# Basement humidity level / percentage ?



## Drifthopper

Does anyone have any info on what is an “acceptable”  level for humidity in a regular house basement?

What I am asking on “acceptable” , is how high can the humidity be allowed to get before mold and mildew start to form? 

House is a two story colonial,  built in 1977,  poured concrete basement, about 800 sq. ft. , not finished, glass block windows with center screens that I do not open,  washer / dryer / work bench / furnace and wood furnace off to one end under family room, sump pump in far corner…standard, solid basement.

The guy that sold the house left an old dehumidifier, (  like from 1977 ).   Seeing that it was old and having it look like a big energy monster, I would only run it every so often.   

Well, one yr, un-packing Christmas decorations, quite a few items had mold on them, these were tossed. 

So, two summers ago I got  a new dehumidifier and a small digital temperature / humidity level reader :  Temp on top , Humidity on the bottom. 

Last summer, I was running the dehumidifier on “dry” (there are three settings, normal, dry, and Extra dry” ) Dry is the middle setting. 

My typical humidity level was around 48% to 55% ,   basically right around 50%.     BUT…..the machine was running ALL THE TIME..  So even with this new dehumidifier, it still added $15 to 20 bucks every month to the electric bill, spring , summer and early fall.  

This season, 2010 – To save on the electric bill, I have the dehumidifier set on “normal” , it does not run / cycle near as much,  but my humidity level is around 60 % to 67%  ( 67% is the highest I’ve seen on the digital reader)   

Basement temperature is about the same, 62, 64, sometimes 68, depending on how hot it is outside. 


Now ….i understand that all houses are different and everyone’s situation/set up is different, but there has to be some type of baseline to say what is ok, and what is not. 

Any input (or links for info) is greatly appreciated.


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## tiber

(this should probably be in the DIY forum)...

I shoot for 70% humidity. 

The actual humidity is about 68% by my super duper humidity thing.

Check the sump lid. It should have a rubber ring or similar gasket around it. If this is in poor condition, it's a cheap fix. If you live near water such as myself, most of your humidity is coming through the sump even on days when it's not really humid out.


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## EatenByLimestone

Why don't you open the windows and get some air in there to help dry things out?

Matt


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## SteveKG

May we assume the dryer is vented to outdoors? I realize this isn't the problem, but I just want to be certain it isn't adding to that problem.

What is the ambient humidity [what's the normal outdoor humidity around there].

Could be that if you could circulate outdoor air through the basement and back out, it would help, at least when it isn't cold outdoors. The electricity used by a fan to do so would have to be figured, as in whether it is less than running a dehumidifier, of which it sounds as if you need more than one. Or might.


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## velvetfoot

I've insulated the basement walls and find there is no condensation there.  I bet if I insulated the floor there'd be less cool surface for condensation as well.  I don't think opening the windows is the answer;  it'll just bring in humid, moisture-laden air to a cooler area where it'll make for a higher relative humidity since the cooler air won't hold as much moisture.


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## jklingel

The numbers you want are "30 to 50%", according to a chart I read on healthyheating.com. I have also seen those numbers elsewhere. Further, bacterial, viral, allergic rhinitis and asthma, respiratory infections, and ozone production problems actually increase below 30% RH. GL. john


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## velvetfoot

I just looked at weather.com .  
It's 87% rel. humidity out there now, and I guess in here too since I don't have air conditioning.
I think this is a summer time question, not a winter heating thing.


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## woodburn

This is a great post.  I've also wondered the same thing for my basement.  I would think that 55% would be the highest you would want to allow.  I too have a humidity meter down there and I keep mine at 50%.  I notice once it hits 60% I feel a difference in the air and it gets a bit of a scent.  I've never had any issues with mold.  

I'd go back to the "dry" setting.  Carefully check the grade around the house and make sure EVERYTHING is pitched away nice.  Also, are your gutter leaders long enough?  Making sure of things like that might make the machine run much less.  I also like Steve's suggestion of checking the dryer vent.  

Good luck!


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## Jack Straw

I believe that you want to keep it under 60%. Letting heat/or the sun in will raise the air temperature. As the temperature rises the relative humidity will go down. You are basically drying out the air. The only time you want to bring outside air in is when the humidity is low. If there is dew on the lawn in the morning you definitely don't want to bring in that air.


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## Highbeam

I was told to keep my bedroom's air below 50% to limit the dust mites. In reality we are nearer 60% on average. For a basement, your current 60-67% is just fine and not going to cause mold on the surface if you are getting 60-67% everywhere. My guess is that if you could measure the humidity between an exterior wall and a stack of boxes (where you found mold) you would find much higher RH levels than you do out in the middle of the room or near the dehumidifier. You need air circulation to get all the water out.


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## Drifthopper

Thanks for the replies ..guys... 

Limestone....when i use to open the small windows in the glass blocks, the humidity seemed higher,  i think having it all closed up doesn't allow moisture in......???

Steve...yes, vented outside.    I'm in WNY...close to Lake Erie..summer humidity is always high...60 to 80% , some days higher...

John....my humidity down there during the buring season is 30 to 40 % ....maybe lower 25%/28% if it's real cold outside for an extended time. (month) , so to get 30% in the summer would be very tough.   my dehumidifier would be always running to get 50% . 

Foot.......just askin' a question.....someone out there may have info i could put to use. 

Woodburn...thanks,  on my temp/humidity meter,  last night it was 68 degrees, with 68 % humidity, and in the upper coner of the digital reader was a little smile face with "comfort" after it, ,,,,, so the meter tells ya a good level, but i don't know how it relates ,/ if it relates to a basement. 

Jack...60% seems good / ok.   no smell or odors. 

Highbeam.....one thing i forgot to type in my original post , was i doo run a fan also.   just a simple pedistal ocillating fan to keep the air moving, i'll tune this on and off depending on what the outside temps are,,,,high,,,80* plus...fan on , 70* or below..fan off...sometimes i'll just run it during the day....on in the AM , off in the PM.    and the boxes with the Christmas decorations are about 1" away from the wall, and up on planks on 2 x 4's off the floor.  i figure with the fan goin' and having them away from the wall and off the floor the air will be able to move around 'em. 

Maybe i'll try a drier setting " more dry" just during the night......???.......and just watch the humidity level....


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## vvvv

http://www.smartvent.net/crawlspacevent.htm
dewpoints have to be proper for drying, this has a computer to figure out when to vent/blow


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## yanksforever

30 to 50 is the ideal humidity


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## Drifthopper

From Blimp's link...........

"The most important fact is how quickly crawl space relative humidity rises and falls
with outdoor vapor pressures. When a weather front moves in or out, and outdoor
vapor pressure rises or falls, humidity in both crawl spaces rises or falls, immediately. 


If moisture had to move through the ground and vapor barriers, these relative
humidity changes could not possibly occur immediately. 

"""""The average relative humidity in the home without the vapor pressure controlled
device is 70%, """""

whereas the home with the device averaged 52%. Using a fan only at
the right time becomes highly beneficial. 

This is winter. In summer, without a ventilator, even with all the foundation vents
open, the relative humidity will be 80 to 90%. See Reference : Samuelson “Relative
humidity exceeded 90% for 44 weeks”. 



................Ok..... copied this from above  - 

The average relative humidity in the home without the vapor pressure controlled
device is 70%,

......................So.....is 70% ...Bad..????

that link is selling a product,,,,but says nothing about what humidity level is bad.


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## coolidge

Is your rim joist properly insulated? Is the moisture entering through the concrete floor, or the blocks?  Try taping a piece of plastic to the floor and wall to see if moisture is traveling through them, there should be water dropplets on the backside of the plastic after a few days.


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## semipro

We keep ours at 60-65% RH.  If it gets any higher than that we start noticing the smell of mold.   So, if your goal is preventing mold growth that might the right level.


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## Laszlo

Aim for between 25% and 60% relative humidity for your living spaces. Mold and mildew is mostly an issue at 70% RH or more, so your dehumidifier's "normal" setting should be fine. However, don't just measure the air in the middle of the basement--the relevant measurement is the RH near potential condensing surfaces, like against cooler walls and floors.



EatenByLimestone said:


> Why don't you open the windows and get some air in there to help dry things out?


Don't do this. As velvetfoot stated, letting in moist/warm outside air to a cool basement will raise the humidity in the space and potentially lead to condensation on surfaces and a higher risk of mold. Instead, make sure you tighten up any air leaks with caulk and spray foam to stop moisture-laden air from entering. Pay particular attention to service penetrations such as around pipes and wiring. Properly insulating and air sealing the rim joists can be equivalent to closing off a window-sized leak.



coolidge said:


> Is your rim joist properly insulated? Is the moisture entering through the concrete floor, or the blocks? Try taping a piece of plastic to the floor and wall to see if moisture is traveling through them, there should be water dropplets on the backside of the plastic after a few days.


 
This is good advice. Use some clear polyethylene, stretched tightly as you can get it and taped down on all sides. Wait a few days, then have a look at what side the water collects on. If the droplets are on the side you can touch, it's moisture from humid air condensing against the cool concrete. If water collects under the poly, then moisture is migrating through the concrete.

Though building scientists have shown that air leaks move _far_ more moisture than vapor diffusion--according to the DoE, air movement accounts for 98% of water vapor movement! So vapor barriers should be a secondary concern after you do a thorough air sealing.


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## USMC80

Try and keep mine between 50-60 %


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## Ashful

Drifthopper said:


> Does anyone have any info on what is an “acceptable” level for humidity in a regular house basement?


 
40 - 60% is generally recommended as ideal, less than 40% indoor being an irritant for most folks (dry sinuses, etc.) and above 60% lending to the possibility of mold / mildew.  Most dehumidifiers are actually set to "dry" = 40 - 50% and "normal" = 50 - 60%, as you already noticed.



EatenByLimestone said:


> Why don't you open the windows and get some air in there to help dry things out?


 
Everyone has a different climate, but in climes where dehumidifiers are required, this is usually not a good idea.  Outside air is usually where the humidity comes from.  Make sure your sump well and perimeter are sealed, and then you can successfully dry the air within.


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## hearthofgold

Drifthopper said:


> Does anyone have any info on what is an “acceptable”  level for humidity in a regular house basement?
> 
> 
> Drifthopper, have I ever got the answer for you. You could fix the problem by this afternoon, I did, and that was 5 or 6 years ago. Everyone is going to love this!!
> 
> I had a bad humidity problem, and you could smell it when I opened the basement door. I used a dehumidifier for years, and played the empty the water jug game 2 times a day for years, and it drove the electric bill up the old wazoooo.
> 
> Then one day I'm driving home from work and hear an advertisement on the radio, and it was asking if I had a damp moldy basement, bla bla bla, visit our website. So I visit the site, and it shows a vertical piece of duct work, starting a few inches from the floor, and just before the ceiling it exits into a hole in the wall. So the site goes on and on about how great it is, letting you think there is some kind of magic going on, because they weren't saying how it works, but it was going for $1200.00, which you only find out by calling them. So I pull up the reins on my pony, thanked him for his time and didn't get scalped that day.
> 
> Anyway, I'm looking at it and thinking there couldn't be much more than a fan and motor in there. So I hop my pony on down to the local Home Depot, tail and all, and I figured I'd do a little experiment, found a little motor with a 9 bladed plastic fan, already mounted in a piece of 8 or 9 inch duct. Its intended use is for when you have a cold room, you draw air from the warm part of your heating system and direct it to the cooler room. The motor is the same one they used to put in the old record players, totally silent, and I bought a flexible hose. My basement window pains come out by sliding a small piece of tapered metal, which held the glass in place. I replaced it with a piece of plywood and cut a round hole for the duct. Then I attached the hose and made it so it hangs about four inches off the floor. When I tell you that within one hour the smell was totally gone I'm not kidding. My wife and I were almost beside ourselves in disbelief. There is just a pleasant neutral smell, and very comfortable, which is now my man cave. Got my hobby table, exercise equipment, room for jogging, rc cars and helicopters, and I'm the man now.
> 
> The unit they were selling had a humidity sensor to shut it off and on. Big woop. And they wanted hundreds of dollars to install it. My fan runs 24/7/365 and costs $10 per year in electric, that's right ten dollars. I just replaced the motor in 2012. It still ran but would stop for whatever reason, and go again if I pushed the fan, so I figured I got my moneys worth out of it and didn't want any problems, and was probably on it's way out anyway.
> 
> What happens is that in the summer the hot outside air gets in and contacts the cooler surface of the basement walls, hits the dew point, which is when a certain amount of hot hits a certain amount of cool, and moisture forms by condensing, which is called condensation. Never ever open the windows in the summer as it will not dry out anything.
> 
> By having the fan going all the time the air never has a chance to condense. My fan actually changes the basement air two times per hour. You just figure out cubic feet of the basement and how many cubic feet an hour the fan moves. And guess what, if I did have that horrible gas called radon, which rises from the earth in enclosed spaces, it's gone too. So I don't mind having it running all year, especially for ten dollars.
> 
> Guess what, in another article I told about closing all my hot air registers, since I heat with wood, because I was drawing air out of the duct work, and wasting wood, and never knew it until recently, after all the years of using wood, from the early seventies and how much better everything is, using less wood, and more stable temperature.  But guess what, where my basement used to be in the fifties it's now in the sixties and it wouldn't be like that without the fan.  Man talk about a good deal, this is it.
> 
> Now, I have to admit, there is ever the slightest amount of moisture, but the only way I know this is because if I keep clothes down there for a very long time it does pick up a tiny bit of smell. Big woop, the cave is rocking and rolling.
> 
> I think back then it cost me $86, so it's got to be a bit higher today, but can you say big woop?
> 
> You're gonna love this so spread the word. Any handyman could add this to his services.
> 
> Good luck.
> 
> 
> 
> 
> What I am asking on “acceptable” , is how high can the humidity be allowed to get before mold and mildew start to form?
> 
> House is a two story colonial,  built in 1977,  poured concrete basement, about 800 sq. ft. , not finished, glass block windows with center screens that I do not open,  washer / dryer / work bench / furnace and wood furnace off to one end under family room, sump pump in far corner…standard, solid basement.
> 
> The guy that sold the house left an old dehumidifier, (  like from 1977 ).   Seeing that it was old and having it look like a big energy monster, I would only run it every so often.
> 
> Well, one yr, un-packing Christmas decorations, quite a few items had mold on them, these were tossed.
> 
> So, two summers ago I got  a new dehumidifier and a small digital temperature / humidity level reader :  Temp on top , Humidity on the bottom.
> 
> Last summer, I was running the dehumidifier on “dry” (there are three settings, normal, dry, and Extra dry” ) Dry is the middle setting.
> 
> My typical humidity level was around 48% to 55% ,   basically right around 50%.     BUT…..the machine was running ALL THE TIME..  So even with this new dehumidifier, it still added $15 to 20 bucks every month to the electric bill, spring , summer and early fall.
> 
> This season, 2010 – To save on the electric bill, I have the dehumidifier set on “normal” , it does not run / cycle near as much,  but my humidity level is around 60 % to 67%  ( 67% is the highest I’ve seen on the digital reader)
> 
> Basement temperature is about the same, 62, 64, sometimes 68, depending on how hot it is outside.
> 
> 
> Now ….i understand that all houses are different and everyone’s situation/set up is different, but there has to be some type of baseline to say what is ok, and what is not.
> 
> Any input (or links for info) is greatly appreciated.


----------



## hearthofgold

Drifthopper said:


> Does anyone have any info on what is an “acceptable”  level for humidity in a regular house basement?
> 
> What I am asking on “acceptable” , is how high can the humidity be allowed to get before mold and mildew start to form?
> 
> House is a two story colonial,  built in 1977,  poured concrete basement, about 800 sq. ft. , not finished, glass block windows with center screens that I do not open,  washer / dryer / work bench / furnace and wood furnace off to one end under family room, sump pump in far corner…standard, solid basement.
> 
> The guy that sold the house left an old dehumidifier, (  like from 1977 ).   Seeing that it was old and having it look like a big energy monster, I would only run it every so often.
> 
> Well, one yr, un-packing Christmas decorations, quite a few items had mold on them, these were tossed.
> 
> So, two summers ago I got  a new dehumidifier and a small digital temperature / humidity level reader :  Temp on top , Humidity on the bottom.
> 
> Last summer, I was running the dehumidifier on “dry” (there are three settings, normal, dry, and Extra dry” ) Dry is the middle setting.
> 
> My typical humidity level was around 48% to 55% ,   basically right around 50%.     BUT…..the machine was running ALL THE TIME..  So even with this new dehumidifier, it still added $15 to 20 bucks every month to the electric bill, spring , summer and early fall.
> 
> This season, 2010 – To save on the electric bill, I have the dehumidifier set on “normal” , it does not run / cycle near as much,  but my humidity level is around 60 % to 67%  ( 67% is the highest I’ve seen on the digital reader)
> 
> Basement temperature is about the same, 62, 64, sometimes 68, depending on how hot it is outside.
> 
> 
> Now ….i understand that all houses are different and everyone’s situation/set up is different, but there has to be some type of baseline to say what is ok, and what is not.
> 
> Any input (or links for info) is greatly appreciated.





Drifthopper said:


> Does anyone have any info on what is an “acceptable”  level for humidity in a regular house basement?
> 
> What I am asking on “acceptable” , is how high can the humidity be allowed to get before mold and mildew start to form?
> 
> House is a two story colonial,  built in 1977,  poured concrete basement, about 800 sq. ft. , not finished, glass block windows with center screens that I do not open,  washer / dryer / work bench / furnace and wood furnace off to one end under family room, sump pump in far corner…standard, solid basement.
> 
> The guy that sold the house left an old dehumidifier, (  like from 1977 ).   Seeing that it was old and having it look like a big energy monster, I would only run it every so often.
> 
> Well, one yr, un-packing Christmas decorations, quite a few items had mold on them, these were tossed.
> 
> So, two summers ago I got  a new dehumidifier and a small digital temperature / humidity level reader :  Temp on top , Humidity on the bottom.
> 
> Last summer, I was running the dehumidifier on “dry” (there are three settings, normal, dry, and Extra dry” ) Dry is the middle setting.
> 
> My typical humidity level was around 48% to 55% ,   basically right around 50%.     BUT…..the machine was running ALL THE TIME..  So even with this new dehumidifier, it still added $15 to 20 bucks every month to the electric bill, spring , summer and early fall.
> 
> This season, 2010 – To save on the electric bill, I have the dehumidifier set on “normal” , it does not run / cycle near as much,  but my humidity level is around 60 % to 67%  ( 67% is the highest I’ve seen on the digital reader)
> 
> Basement temperature is about the same, 62, 64, sometimes 68, depending on how hot it is outside.
> 
> 
> Now ….i understand that all houses are different and everyone’s situation/set up is different, but there has to be some type of baseline to say what is ok, and what is not.
> 
> Any input (or links for info) is greatly appreciated.




Drifthopper, have I ever got the answer for you. You could fix the problem by this afternoon, I did, and that was 5 or 6 years ago. Everyone is going to love this!!

I had a bad humidity problem, and you could smell it when I opened the basement door. I used a dehumidifier for years, and played the empty the water jug game 2 times a day for years, and it drove the electric bill up the old wazoooo.

  Then one day I'm driving home from work and hear an advertisement on the radio, and it was asking if I had a damp moldy basement, bla bla bla, visit our website. So I visit the site, and it shows a vertical piece of duct work, starting a few inches from the floor, and just before the ceiling it exits into a hole in the wall. So the site goes on and on about how great it is, letting you think there is some kind of magic going on, because they weren't saying how it works, but it was going for $1200.00, which you only find out by calling them. So I pull up the reins on my pony, thanked him for his time and didn't get scalped that day.

Anyway, I'm looking at it and thinking there couldn't be much more than a fan and motor in there. So I hop my pony on down to the local Home Depot, tail and all, and I figured I'd do a little experiment, found a little motor with a 9 bladed plastic fan, already mounted in a piece of 8 or 9 inch duct. Its intended use is for when you have a cold room, you draw air from the warm part of your heating system and direct it to the cooler room. The motor is the same one they used to put in the old record players, totally silent, and I bought a flexible hose. My basement window pains come out by sliding a small piece of tapered metal, which held the glass in place. I replaced it with a piece of plywood and cut a round hole for the duct. Then I attached the hose and made it so it hangs about four inches off the floor. When I tell you that within one hour the smell was totally gone I'm not kidding. My wife and I were almost beside ourselves in disbelief. There is just a pleasant neutral smell, and very comfortable, which is now my man cave. Got my hobby table, exercise equipment, room for jogging, rc cars and helicopters, and I'm the man now. 

The unit they were selling had a humidity sensor to shut it off and on. Big woop. And they wanted hundreds of dollars to install it. My fan runs 24/7/365 and costs $10 per year in electric, that's right ten dollars. I just replaced the motor in 2012. It still ran but would stop for whatever reason, and go again if I pushed the fan, so I figured I got my moneys worth out of it and didn't want any problems, and was probably on it's way out anyway.

What happens is that in the summer the hot outside air gets in and contacts the cooler surface of the basement walls, hits the dew point, which is when a certain amount of hot hits a certain amount of cool, and moisture forms by condensing, which is called condensation. Never ever open the windows in the summer as it will not dry out anything.

By having the fan going all the time the air never has a chance to condense. My fan actually changes the basement air two times per hour. You just figure out cubic feet of the basement and how many cubic feet an hour the fan moves. And guess what, if I did have that horrible gas called radon, which rises from the earth in enclosed spaces, it's gone too. So I don't mind having it running all year, especially for ten dollars.

Guess what, in another article I told about closing all my hot air registers, since I heat with wood, because I was drawing air out of the duct work, and wasting wood, and never knew it until recently, after all the years of using wood, from the early seventies and how much better everything is, using less wood, and more stable temperature.  But guess what, where my basement used to be in the fifties it's now in the sixties and it wouldn't be like that without the fan.  Man talk about a good deal, this is it.

Now, I have to admit, there is ever the slightest amount of moisture, but the only way I know this is because if I keep clothes down there for a very long time it does pick up a tiny bit of smell. Big woop, the cave is rocking and rolling.

I think back then it cost me $86, so it's got to be a bit higher today, but can you say big woop?

You're gonna love this so spread the word. Any handyman could add this to his services.

Good luck.


----------



## Ashful

hearthofgold said:


> What happens is that in the summer the hot outside air gets in and contacts the cooler surface of the basement walls, hits the dew point, which is when a certain amount of hot hits a certain amount of cool, and moisture forms by condensing, which is called condensation. Never ever open the windows in the summer as it will not dry out anything.
> 
> By having the fan going all the time the air never has a chance to condense. My fan actually changes the basement air two times per hour.


Are these two statements not contradictory?  1)  Never let fresh air into your basement, as it carries fresh moisture.  2)  My fan actually changes the basement air two times per hour.  Not knocking your system, mind you, just questioning the reasoning.



hearthofgold said:


> My fan runs 24/7/365 and costs $10 per year in electric, that's right ten dollars.


For every cubic foot of air you pump out of the house, a cubic foot of fresh air must be drawn in to replace it.  This comes in thru gaps in windows, doors, soffets, sill plate, etc.  Aren't you ignoring the cost of heating loss to this forced draft?  This associated cost may be on par with running a dehumidifier.

I think that what's happening here is that by reducing basement air pressure, you are forcing (mostly) dry air from the first floor into the basement.  During heating season or when AC is running in summer, this probably works pretty well.  When it's mild outside, and you just have the windows open, this system probably has zero effect, but that may coincide with when it is least necessary.


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## velvetfoot

I just might try that fan thing.  Not much to lose, esp. if it would reduce radon levels as well.
Getting back to original question, this on line dew point calculator seems very useful:
http://dpcalc.org/


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## SONOCATIVO

My house was built 1925 in 4 stages by a farmer, the main house was just one large room over a basement, then added a 1/2 story, later added what is the kitchen and another 1/2 story. then 2 additions on either side of the house. The kitchen is actually on a dirt crawl space thats about 18" with ducts and plumbing thats hard to get to.... the rest of the basement is concrete, stone and brick.... any resources they had to build with back then.... Id love to insulate it better, but thinking the only option i have here is to have a new basement dug....Its not as bad with smells, mold, mildew as when I first bought it 3 years ago, had a ton of cleaning to do ( vandalized bank foreclosure ) had to totally gut the place.


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## sportbikerider78

Great thread.
I keep my basement on the lower side 60%.  I have a block foundation and poured floor.  

Question for you guys.  In many places in my basement there is no 'cap' on top of about half the block wall.  There is the framing of the home on it, but that does not completely seal off about half of the block. 
What can i use to economically seal off the top of the block (about 4")?  I think I get cool air coming up through the block and condensing with warmer air.


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## SONOCATIVO

Stuff fiberglass in it and fill with expandable foam? Use items that wont mold or mildew due to moisture.


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## Ashful

I like overkill, so I'd be dropping a length of rebar in each hole and filling with concrete.  If you just want insulation and moisture barrier, I'd be doing closed-cell spray foam... not Great Stuff, but one of the portable / disposable kits used by the pro's who do spray foam installs.


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## sportbikerider78

Yes.  I am just looking for a vapor barrier.  I am going to do closed cell foam sheets on the basement eventually and want to start preventing any kind of drafting.


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## ocampo

newbie here


Wet or damp basements are the most frequent complaint of homeowners. Traditional, decades-old basement waterproofing methods have not passed the test of time: "Over 60 per cent of basements have moisture seepage in one form or another, while 38 per cent experience mold and fungus growth due to an elevated moisture level." – The American Society of Home Inspectors. Slab-on-grade buildings suffer similar moisture problems.


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## delp

Ashful said:


> I like overkill, so I'd be dropping a length of rebar in each hole and filling with concrete.  If you just want insulation and moisture barrier, I'd be doing closed-cell spray foam... not Great Stuff, but one of the portable / disposable kits used by the pro's who do spray foam installs.



Ashful…what's the difference between the kit closed-cell and the Great Stuff?


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## mass_burner

I like 45-50 %. It also keeps the space a lot cooler. On a 90d day, 80% humidity, folks think I have AC in the basement.


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## Ashful

delp said:


> Ashful…what's the difference between the kit closed-cell and the Great Stuff?


I wasn't saying I wouldn't use Great Stuff because it's not closed cell, I was saying I'd be using a portable kit over cans of Great Stuff due to the size of the job.  I've only used Great Stuff a few times, but I think it actually is closed-cell foam.


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## delp

Ashful said:


> I wasn't saying I wouldn't use Great Stuff because it's not closed cell, I was saying I'd be using a portable kit over cans of Great Stuff due to the size of the job.  I've only used Great Stuff a few times, but I think it actually is closed-cell foam.


Thanks for your thoughts Ashful! I just finished doing a "poor-person's" joist cavity insulation project at my house. Since it's easily reversible and ended up costing less than $100, I used 2" foil faced rigid insulation cut about ½" shy of the two dimensions and sealed it in place with great stuff. Hoping this winter will see less air infiltration in the basement. 

Anyway, I thought I had missed something I should have known about the Great Stuff when I read your post.


----------



## blades

Delp ,no, you did ok, eps closed cell in joist cavities and on top of sill -seal edges with any of the various spray cans of foam. there are some that are water clean up( latex based) vs great stuff- work just as well. sheet foam by what I have read about 2" thick . Fiberglass batts allow  too much air passage and with that vapor passage as well. the key here is to not allow an air gap at the floor sill framing doing so could allow moisture to condense behind foam. Of course total sprayed in foam is the best. small kits are available from the various box stores. these are kind of pricey from what I have seen to the point where a contractor isn't all that much more saves headaches. Years ago when I read about this ( Mother Earth news early 70's ) I went and felt around the top of my blocks, holy yikes the amount of air traveling up out of blocks felt like a hurricane in some places in that particular home. Spray foam was brand new back then then and the formaldehyde issue was just being raised, so most were doing fiberglass, since that time the dirty truth about air migration and r value shrinkage of fiberglass( as the temps dip) has seen the light. Mfgs of fiberglass knew it, public didn't still isn't widely known and is being down played by the fiberglass mfg. ( pretty standard operating procedure for mfgs now days- case in point,automotive ignition switches as a point of reference)

Granite counter tops are taking a hit now from the radon issue- being played upon by the the alternative counter top mfgs ( course they conveniently forget to mention their own issues as far as toxins are concerned.) Ceramic tile counters are taking hits as well - not the tiles but the grouting and under layment being a home for nasties - so its difficult to win no mater what. 

Course with all that air traveling through the basement- Radon wasn't an issue- something else that has not been taken into consideration ya sure they take a reading right at the sump and it goes high right there and oh my ya got to spend a couple grand to mitigate it - where as in the rest of the space it possibly is way below minimums over all. Scare tactics for sales. Not all of us have super tight sealed up homes - sometimes not even all that possible short of tearing half the structure down. Isn't it amazing that so many of us survive past 30 years old vs all these terrible things.


----------



## dunned8698

hearthofgold said:


> Drifthopper, have I ever got the answer for you. You could fix the problem by this afternoon, I did, and that was 5 or 6 years ago. Everyone is going to love this!!
> 
> I had a bad humidity problem, and you could smell it when I opened the basement door. I used a dehumidifier for years, and played the empty the water jug game 2 times a day for years, and it drove the electric bill up the old wazoooo.
> 
> Then one day I'm driving home from work and hear an advertisement on the radio, and it was asking if I had a damp moldy basement, bla bla bla, visit our website. So I visit the site, and it shows a vertical piece of duct work, starting a few inches from the floor, and just before the ceiling it exits into a hole in the wall. So the site goes on and on about how great it is, letting you think there is some kind of magic going on, because they weren't saying how it works, but it was going for $1200.00, which you only find out by calling them. So I pull up the reins on my pony, thanked him for his time and didn't get scalped that day.
> 
> Anyway, I'm looking at it and thinking there couldn't be much more than a fan and motor in there. So I hop my pony on down to the local Home Depot, tail and all, and I figured I'd do a little experiment, found a little motor with a 9 bladed plastic fan, already mounted in a piece of 8 or 9 inch duct. Its intended use is for when you have a cold room, you draw air from the warm part of your heating system and direct it to the cooler room. The motor is the same one they used to put in the old record players, totally silent, and I bought a flexible hose. My basement window pains come out by sliding a small piece of tapered metal, which held the glass in place. I replaced it with a piece of plywood and cut a round hole for the duct. Then I attached the hose and made it so it hangs about four inches off the floor. When I tell you that within one hour the smell was totally gone I'm not kidding. My wife and I were almost beside ourselves in disbelief. There is just a pleasant neutral smell, and very comfortable, which is now my man cave. Got my hobby table, exercise equipment, room for jogging, rc cars and helicopters, and I'm the man now.
> 
> The unit they were selling had a humidity sensor to shut it off and on. Big woop. And they wanted hundreds of dollars to install it. My fan runs 24/7/365 and costs $10 per year in electric, that's right ten dollars. I just replaced the motor in 2012. It still ran but would stop for whatever reason, and go again if I pushed the fan, so I figured I got my moneys worth out of it and didn't want any problems, and was probably on it's way out anyway.
> 
> What happens is that in the summer the hot outside air gets in and contacts the cooler surface of the basement walls, hits the dew point, which is when a certain amount of hot hits a certain amount of cool, and moisture forms by condensing, which is called condensation. Never ever open the windows in the summer as it will not dry out anything.
> 
> By having the fan going all the time the air never has a chance to condense. My fan actually changes the basement air two times per hour. You just figure out cubic feet of the basement and how many cubic feet an hour the fan moves. And guess what, if I did have that horrible gas called radon, which rises from the earth in enclosed spaces, it's gone too. So I don't mind having it running all year, especially for ten dollars.
> 
> Guess what, in another article I told about closing all my hot air registers, since I heat with wood, because I was drawing air out of the duct work, and wasting wood, and never knew it until recently, after all the years of using wood, from the early seventies and how much better everything is, using less wood, and more stable temperature.  But guess what, where my basement used to be in the fifties it's now in the sixties and it wouldn't be like that without the fan.  Man talk about a good deal, this is it.
> 
> Now, I have to admit, there is ever the slightest amount of moisture, but the only way I know this is because if I keep clothes down there for a very long time it does pick up a tiny bit of smell. Big woop, the cave is rocking and rolling.
> 
> I think back then it cost me $86, so it's got to be a bit higher today, but can you say big woop?
> 
> You're gonna love this so spread the word. Any handyman could add this to his services.
> 
> Good luck.


_______________________
Heartofgold, I really appreciate your post, and want to try this in my basement.  Do you have anything off-the-shelf, or a link to a website, that will explain how to put this low-level, low-power exhaust fan in my crawlspace (this "crawlspace" is a misnomer...it's tall enough that I need a ladder to touch the floor above). 
Sign me, headed to Home Depot


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## thewoodlands

Drifthopper said:


> Does anyone have any info on what is an “acceptable”  level for humidity in a regular house basement?
> 
> What I am asking on “acceptable” , is how high can the humidity be allowed to get before mold and mildew start to form?
> 
> House is a two story colonial,  built in 1977,  poured concrete basement, about 800 sq. ft. , not finished, glass block windows with center screens that I do not open,  washer / dryer / work bench / furnace and wood furnace off to one end under family room, sump pump in far corner…standard, solid basement.
> 
> The guy that sold the house left an old dehumidifier, (  like from 1977 ).   Seeing that it was old and having it look like a big energy monster, I would only run it every so often.
> 
> Well, one yr, un-packing Christmas decorations, quite a few items had mold on them, these were tossed.
> 
> So, two summers ago I got  a new dehumidifier and a small digital temperature / humidity level reader :  Temp on top , Humidity on the bottom.
> 
> Last summer, I was running the dehumidifier on “dry” (there are three settings, normal, dry, and Extra dry” ) Dry is the middle setting.
> 
> My typical humidity level was around 48% to 55% ,   basically right around 50%.     BUT…..the machine was running ALL THE TIME..  So even with this new dehumidifier, it still added $15 to 20 bucks every month to the electric bill, spring , summer and early fall.
> 
> This season, 2010 – To save on the electric bill, I have the dehumidifier set on “normal” , it does not run / cycle near as much,  but my humidity level is around 60 % to 67%  ( 67% is the highest I’ve seen on the digital reader)
> 
> Basement temperature is about the same, 62, 64, sometimes 68, depending on how hot it is outside.
> 
> 
> Now ….i understand that all houses are different and everyone’s situation/set up is different, but there has to be some type of baseline to say what is ok, and what is not.
> 
> Any input (or links for info) is greatly appreciated.


We like our basement between 35 to 45 percent. 

This summer we've kept the basement windows closed because of the high humidity. Our basement temps have been between 68-70 this summer which has been nice.


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## fbelec

my dehumidifier has a variable dry to moist knob. i run mine halfway which the knob says is normal. feels like air cond here also. we've had mid 90's here everyday for over a week. the temp just today is up to 74 and will drop down a little by morning. before the dehum any metal started to rust and it smelled musty. nothing had mold on it. i go into alot of basement with my job and i find most people do the wrong thing with there dehum. they plug it in and turn it all the way to the driest setting. it sends the electric bill up for energy used and burns out the dehum in about two years and then we can talk about the heat that it makes in the basement which in turn heats up the next floor above. you might think that it's not dry enough so turn the unit lower. dehum's are made to do a certain amount if it is not doing it instead of cranking the unit to run hard get a second unit set them both to normal and it will dry out and since they both are not running hard it will be minimal on the power bill because they both are cycling like they should.


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## Poindexter

So how much grading?  What slope, what rise and run?  I am going to need a surveyor's transit to see what is possible on my lot, but a goal or starting point to work from would be nice.

The further I get into mold abatement in my 1980 build, the bigger headache it is becoming.  It seems the ideal solution would be to pull the house forward on the lot about 15 feet.

I was in the crawl space this summer, I have poured concrete walls, vapor barrier over dirt for the floor, and salt stains in the concrete at opposite corners.  One near the hosebib on the front and one at the down spout on the rear corner.  I rerouted the downspout, five, six, seven years ago, it empties 14 feet from the foundation now...

Current plan is to rent a skid steer spring 19 and make all the slope I can around the building while still able to drain via gravity over the curb onto the street.


----------



## blades

pointdexter- some of your issues could be related to what is below the surface. Type of sub soil & ground water flows sub surface.  At one of my previous homes located 1/2 down a hill   and an 30 home subdivision on top of said hill  created a subsurface flow  that drove me nutz. ended up installing a poured concrete deflection wall sub surface, 6ft  high wall about 2ft under surface  back side from house piped out around  & past home only way I could control it , Plus I built a surface berm for deflection of that water as well.  Before the subdivision was built I had no problems. After it was built and all the homes constructed I would get a river in back yard and across the front yard- neighbor across street suffered same problems, both of us did a lot of remedial landscaping to control/ deflect water.


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## Ashful

Every basement water issue I've ever had, in 45 years of life and at least a dozen houses, has been resolved on the exterior:

1.  Clean and functional gutters.
2.  Downspouts extended away from the house, preferably running into burried pipe that surfaces more than 30 feet from house.
3.  Filling any low spots around foundation, so all slope is away from foundation for at least 3 feet.
4.  Installing drain pipe, where all else fails.

It's the rare house that will have a wet basement, after following these four principles.


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## blades

That home was dry as a bone for many years prior to the new subdivision. Problem was /is caused by all the run off up there as well as sumps pumping out.  The blame really lies with the city. Couple other areas same thing occurring enough so that the owners in one subdivision are suing the city to rectify there oversight in regards to what the developer did or did not do.


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## Ashful

I hear you.  In PA it is illegal for any property development to affect runoff to or from an adjacent property, so it would be a pretty cut-and-dry case here.  No plans would be approved that consisted of grading which would affect runoff toward your property, and if somehow that managed to happen, the burden would be on the developer to remedy the situation.  You might want to check your local laws, as I suspect they’re similar.


----------



## Highbeam

Ashful said:


> I hear you.  In PA it is illegal for any property development to affect runoff to or from an adjacent property, so it would be a pretty cut-and-dry case here.  No plans would be approved that consisted of grading which would affect runoff toward your property, and if somehow that managed to happen, the burden would be on the developer to remedy the situation.  You might want to check your local laws, as I suspect they’re similar.



It’s not that simple. No, the burden is on the affected homeowner to prove that this new problem is new and that it is caused by the new project. It’s almost never the city’s fault, the project plans were stamped by an engineer.


----------



## Ashful

Highbeam said:


> It’s not that simple. No, the burden is on the affected homeowner to prove that this new problem is new and that it is caused by the new project. It’s almost never the city’s fault, the project plans were stamped by an engineer.



It is actually fairly simple if you can show that the developer deviated from the plans.  It is also not that difficult a case if it can be shown that the plans create a problem, and were approvoved in error.

The more difficult case is when the plans were followed, and there is no clear deficiency in the plans.  Then you have to resort to historical data, such as comparing conditions that cause recent flooding to past similar or worse conditions that did not, and proving there are no new maintenance issues or mitigating factors that would contribute.  I’d agree with you, if this were the case.


----------



## Highbeam

Ashful said:


> It is actually fairly simple if you can show that the developer deviated from the plans.  It is also not that difficult a case if it can be shown that the plans create a problem, and were approvoved in error.
> 
> The more difficult case is when the plans were followed, and there is no clear deficiency in the plans.  Then you have to resort to historical data, such as comparing conditions that cause recent flooding to past similar or worse conditions that did not, and proving there are no new maintenance issues or mitigating factors that would contribute.  I’d agree with you, if this were the case.



As I read it, we are saying almost the same thing. Yes I am a professional engineer and yes I do this for a living.


----------



## Seasoned Oak

thewoodlands said:


> We like our basement between 35 to 45 percent.


Thats seems very dry. The mayo clinic recommends between 45 to 50 as ideal. Too low can dry out your nasal passages and encourage illness. Too low can also cause nose bleeds. Notice the flu and colds are much more common in winter. I shoot for 50 to 60 for our below grade finished basement. We suffer over winter when it stays consistently below 40%.


----------



## thewoodlands

Seasoned Oak said:


> Thats seems very dry. The mayo clinic recommends between 45 to 50 as ideal. Too low can dry out your nasal passages and encourage illness. Too low can also cause nose bleeds. Notice the flu and colds are much more common in winter. I shoot for 50 to 60 for our below grade finished basement. We suffer over winter when it stays consistently below 40%.


I think we hit 37 percent once last summer but the majority of the time we're at 47 percent with a temp between 68-72 this summer.


----------



## ChuckTSI

Have an old 1850 stone home. They built the interior walls inside the stone walls. Only the main center beam sit on the stone. And that is a problem. Stone needs to breathe. If I attempt to seal off the cellar from moisture (30x20 @ 6 feet hight)..  I will end up with water in the stones that won't be able to escape and start causing problems in the winter. The mortar will crumble, etc.  There are way to many entry points for air to get in.

I have been doing lots of reading.  Everyone says. spray foam the stone. Done. But I don't believe it's that simple. Again, stone needs to breathe.
The basement is at 94-96% humidity in the summer.  temps are never higher than 16 degrees C down there and the hot humid summer air just rushes in and condenses.  The reverse happens in winter. same condensation build up as the cellar never drops below 1 degree.C

Previous owner threw up 2x4 framing and pink insulation right up against the rock. When I bought, the insulation was all sagging and the 2x4 were black mold.  I removed it all. The basement improved greatly, but it's still @94-96%. Floor joists seem to be in good shape except the header where cold is rushing in from old windows that they never put in. Was just pink insulation with boards leaning outside the house.

I can't put a dehumidifier. It will never win against outside air coming in.
I can't seal it. Stone needs to breathe or risk greater problems.

I have closed off those windows and used rockwool instead of pink fiberglass.
I added interior perimeter drain to improve drainage to the sump.

I have thought of pinning that dimpled sub floor stuff to the walls. down 4 feet from rim joist. (allow air to pass behind and the stone can dry out).
Then adding pink styrofoam rigid board (down 4ft) over it. 
I would then add 2 layers of 6mil plastic down on the gravel floor. Leaving 12" around the edge of the room for the air to move between the walls and the room.  The walls are never really wet. If they are it's only due to condensation. not seepage through from ground outside.

The idea for me I think it to reduce the surfaces that can release moisture directly to the room. I will never be able to seal it unless I spend 100K to get the foundation redone.


----------



## Ashful

ChuckTSI said:


> Have an old 1850 stone home. They built the interior walls inside the stone walls. Only the main center beam sit on the stone. And that is a problem. Stone needs to breathe. If I attempt to seal off the cellar from moisture (30x20 @ 6 feet hight)..  I will end up with water in the stones that won't be able to escape and start causing problems in the winter. The mortar will crumble, etc.  There are way to many entry points for air to get in.
> 
> I have been doing lots of reading.  Everyone says. spray foam the stone. Done. But I don't believe it's that simple. Again, stone needs to breathe.
> The basement is at 94-96% humidity in the summer.  temps are never higher than 16 degrees C down there and the hot humid summer air just rushes in and condenses.  The reverse happens in winter. same condensation build up as the cellar never drops below 1 degree.C
> 
> Previous owner threw up 2x4 framing and pink insulation right up against the rock. When I bought, the insulation was all sagging and the 2x4 were black mold.  I removed it all. The basement improved greatly, but it's still @94-96%. Floor joists seem to be in good shape except the header where cold is rushing in from old windows that they never put in. Was just pink insulation with boards leaning outside the house.
> 
> I can't put a dehumidifier. It will never win against outside air coming in.
> I can't seal it. Stone needs to breathe or risk greater problems.
> 
> I have closed off those windows and used rockwool instead of pink fiberglass.
> I added interior perimeter drain to improve drainage to the sump.
> 
> I have thought of pinning that dimpled sub floor stuff to the walls. down 4 feet from rim joist. (allow air to pass behind and the stone can dry out).
> Then adding pink styrofoam rigid board (down 4ft) over it.
> I would then add 2 layers of 6mil plastic down on the gravel floor. Leaving 12" around the edge of the room for the air to move between the walls and the room.  The walls are never really wet. If they are it's only due to condensation. not seepage through from ground outside.
> 
> The idea for me I think it to reduce the surfaces that can release moisture directly to the room. I will never be able to seal it unless I spend 100K to get the foundation redone.



I have a dry finished basement, parts of it dating to the 1730’s, and the newest corner of it being 1779.  It’s not that difficult.  I have lived in nothing but old houses (some dating back to late 1600’s) my entire life, and I’ve gotten the basement in every last one of them to hold 50% RH.

In rough order of importance:

1.  Repair or replace any broken or missing gutters.
2.  Run all downspouts into buried PVC piping, drained downhill, far from the house.  If you can’t do this, at least extend all downspouts far from house, and downhill.
3.  Fix any grading around house that sends water toward foundation.
4.  At a minimum, pour a slab floor.  Better is to dig, install perf pipe, gravel, then pour.  My current house has the latter solution, but my two prior houses just had slab poured on dirt floor.
5.  Install a dehumidifier.  If it hasn’t stopped running after a week, install a second dehumidifier.  I have two in my current basement, but it’s over 2000 sq.ft. and broken into several rooms.
6.  Seal around all basement doors and windows.  Seal sill plate or joist penetrations.
7.  Insulate and/or seal basement ceiling, if living space above is not air conditioned in summer.

You are correct, you do not want to directly seal the stone, but stone does not release so much moisture into the basement that a dehumidifier won’t keep up with it.  Air infiltration and a damp dirt floor are the primary enemies, here.  Stone walls do pretty well, with regard to air infiltration, if you seal doors, window, and sill plate / joist penetrations.  I have done this in several cases, and have always achieved RH = 50%, where previous owners had assumed the basement could just never be dry.

Note that items 1 - 3 are all about keeping water away from the foundation.  This is the number one problem, in my experience.


----------



## ChuckTSI

Ashful said:


> I have a dry finished basement, parts of it dating to the 1730’s, and the newest corner of it being 1779.  It’s not that difficult.  I have lived in nothing but old houses (some dating back to late 1600’s) my entire life, and I’ve gotten the basement in every last one of them to hold 50% RH.
> 
> In rough order of importance:
> 
> 1.  Repair or replace any broken or missing gutters.
> 2.  Run all downspouts into buried PVC piping, drained downhill, far from the house.  If you can’t do this, at least extend all downspouts far from house, and downhill.
> 3.  Fix any grading around house that sends water toward foundation.
> 4.  At a minimum, pour a slab floor.  Better is to dig, install perf pipe, gravel, then pour.  My current house has the latter solution, but my two prior houses just had slab poured on dirt floor.
> 5.  Install a dehumidifier.  If it hasn’t stopped running after a week, install a second dehumidifier.  I have two in my current basement, but it’s over 2000 sq.ft. and broken into several rooms.
> 6.  Seal around all basement doors and windows.  Seal sill plate or joist penetrations.
> 7.  Insulate and/or seal basement ceiling, if living space above is not air conditioned in summer.
> 
> You are correct, you do not want to directly seal the stone, but stone does not release so much moisture into the basement that a dehumidifier won’t keep up with it.  Air infiltration and a damp dirt floor are the primary enemies, here.  Stone walls do pretty well, with regard to air infiltration, if you seal doors, window, and sill plate / joist penetrations.  I have done this in several cases, and have always achieved RH = 50%, where previous owners had assumed the basement could just never be dry.
> 
> Note that items 1 - 3 are all about keeping water away from the foundation.  This is the number one problem, in my experience.




Thank you thank you thank you   Glad to hear there is hope. I will follow your plan to a T (other than slab floor. That will never happen until the house is paid. Or if I get ambitious with a cement mixer and 800 bags of concrete. >.<) 

1. Gutters and downspouts are almost complete.  I was afraid of the PVC pipes freezing  underground. How far down you put them?  
2 & 3. Little bit of mortar work at ground level to do and then grading is next.
4 Already did the perimeter drain inside. It's gonna have to be 6mil plastic for now.
5. Bought Dehumidifer early 2017. Just waiting till I finish the work above to install.
6. This is an old root cellar. no access from inside the house. You open a trap door at ground level, then walk down very steep steps to a door into the cellar under the main living area. Almost done sealing the old window areas.
7. I air condition in the summer. But the temperature in cellar never exceeds 16 degrees and I have AC set to 21. I still want to install Reflectix between the joists just for a little added comfort in the winter from the FREEZING floor.  If I install Rockwool batts, afraid the mice will get into it.


----------



## Ashful

ChuckTSI said:


> Thank you thank you thank you   Glad to hear there is hope. I will follow your plan to a T (other than slab floor. That will never happen until the house is paid. Or if I get ambitious with a cement mixer and 800 bags of concrete. >.<)
> 
> 1. Gutters and downspouts are almost complete.  I was afraid of the PVC pipes freezing  underground. How far down you put them?
> 2 & 3. Little bit of mortar work at ground level to do and then grading is next.
> 4 Already did the perimeter drain inside. It's gonna have to be 6mil plastic for now.
> 5. Bought Dehumidifer early 2017. Just waiting till I finish the work above to install.
> 6. This is an old root cellar. no access from inside the house. You open a trap door at ground level, then walk down very steep steps to a door into the cellar under the main living area. Almost done sealing the old window areas.
> 7. I air condition in the summer. But the temperature in cellar never exceeds 16 degrees and I have AC set to 21. I still want to install Reflectix between the joists just for a little added comfort in the winter from the FREEZING floor.  If I install Rockwool batts, afraid the mice will get into it.


Sounds like you're on the right track.  I've never had any issues with the drainage piping freezing, because the only time there's ever water in it is when it's already warm enough for your downspouts to be carrying water.  Also, it's usually always continuously-sloped, so there's no water staying in the piping.  I have these done in three different materials, sch.20 PVC drain pipe near the house, transitioning to 6" corrugated black drain pipe or sch.35 sewer pipe, and no freezing issues with any of these.  Depth varies from 1 to 4 feet, to maintain continuous downward slope, across my undulating yard.  As long as there's no "belly" in the slope of the pipe, it will always stay dry when not doing it's thing.

In the current house, which was built adjacent to a spring (1730's), the prior owner put about a mile of perf pipe under the basement floor before pouring the slab.  This is connected into a drain that runs to the storm basin, which seems to be carrying water most of the year, even when it hasn't rained for a week.  No issues with this one freezing, even though it's penetrating the storm basin only 24" below grade.

Plastic on the floor?  That would probably keep humidity down at least as well as a slab, but there's the obvious durability concerns.  Trying to dehumidify with a dirt floor and no barrier might be pretty darn tough, though.


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## Seasoned Oak

Cant stress enough that keeping water out in the first place pays years of dividends.  Running a dehumidifier can add a lot of dollars to your electric bill. As much as $30 monthly. Which is  more than i spend to make hot water. Although even with a dry basement when its 90% humidity outside some of that finds its way in with air infiltration.


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## Kiotick4010

Best thing we did was to install a hybrid heat pump water heater to replace our old electric water heater.

It allowed us to get rid of the dehumidifier.  The basement air is dry, with no musty smell.

Best of all, it cost only $50 after all of the utility rebates were factored in.


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## Highbeam

after monitoring humidity all winter at 30-35% we have decided to purchase a dehumidifier to lower humidity in the home from 60 to about 40 through the summer. I hung all of the doors in the winter and that 20% makes a couple of them too tight! Dust mites, mildew, and odors seem to like 50%


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## zrock

Most off the shelf dehumidifiers only do 45%.... in the summer if u have windows open or air conditioning running then u will never achieve that. Adjust your doors so they have about 3/16th and u will never have issues.. 

Sent from my SM-G950W using Tapatalk


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## Seasoned Oak

40 to 60 seems to be the sweet spot. Below 40  can cause dry air problems. Iv had furniture crack in winter and wife gets nose bleeds. Above 65-70 can cause dampness problems also. I keep the basement below 65 in summer but it dont have to be too far below that.


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## Ashful

My house runs 19% - 23% all winter.  Your wife would die here, Oak.  [emoji1]

We have been keeping our basement dehumidifiers at 50%, the last several years.  Going down to 40% really jacks up the electric bill, to the tune of a few hundred $$ per month, when running multiple dehumidifiers.  Going up to 60%, we start to notice things getting just a little musty.  At least in our house, 50% seems to be the sweet spot.


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## Seasoned Oak

Ashful said:


> Going down to 40% really jacks up the electric bill, to the tune of a few hundred $$ per month, when running multiple dehumidifiers.  .


 I dont see any reason to try to go lower than 50% Waste of power. Too low humidity fosters illness as does too high humidity.


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## mass_burner

sweet spot here is 55%. but there are so many variables. my basement at primary home is 2x bigger and unfinished, but dehumidifier works less than house on cape which is finished. both homes are the same distance to ocean. also cape house is colder, neither basement is heated.

Sent from my V11 using Tapatalk


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## WiscWoody

I shoot for 55-58% in my full basement during the summer which is short up here. Between that dehumidifier and the AC my electric bill goes from $33 in the winter to $55-60 in the summer. Not bad in my opinion. The charge to be hooked up is $12 of that.


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## Sodbuster

Highbeam said:


> after monitoring humidity all winter at 30-35% we have decided to purchase a dehumidifier to lower humidity in the home from 60 to about 40 through the summer. I hung all of the doors in the winter and that 20% makes a couple of them too tight! Dust mites, mildew, and odors seem to like 50%



Good luck finding one that works. I have 2 Frigidaire's'  that are 3 years old, and they keep blowing codes and stop running the unit. If I unplug them and then plug them in again, they will run for a while then blow another code and crap out on me. They also also make many other brands under private labels.


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## Ashful

Sodbuster said:


> Good luck finding one that works. I have 2 Frigidaire's' that are 3 years old, and they keep blowing codes and stop running the unit. If I unplug them and then plug them in again, they will run for a while then blow another code and crap out on me. They also also make many other brands under private labels.



Three years in a cool basement is not out of the ordinary for dehumidifier lifetime, today. They put such a small amount of refrigerant in them now, thanks to the EPA. It’s also why refrigerators no longer work in a cold garage, the refrigerant condenses and gathers in the coolest part of the system, and the compressor being much warmer doesn’t get any refrigerant, if there is so little in the loop. This leads to inevitable compressor failure. 

I’ve always wondered about the environmental impact of throwing away entire refrigerators and dehumidifiers 4x more frequently than our parents, versus an extra few ounces of r438a, the majority of which will be reclaimed at end of product life.


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## blades

Ashful said:


> Three years in a cool basement is not out of the ordinary for dehumidifier lifetime, today. They put such a small amount of refrigerant in them now, thanks to the EPA. It’s also why refrigerators no longer work in a cold garage, the refrigerant condenses and gathers in the coolest part of the system, and the compressor being much warmer doesn’t get any refrigerant, if there is so little in the loop. This leads to inevitable compressor failure.
> 
> I’ve always wondered about the environmental impact of throwing away entire refrigerators and dehumidifiers 4x more frequently than our parents, versus an extra few ounces of r438a, the majority of which will be reclaimed at end of product life.


  yep just like the desiel fiasco take a unit doing 55-60 mpg add emmision  equipment now gets 20-25 mpg.  so you burn twice as much fuel or more Plus the blue stuff  and spend twice as much time in the repair shop for emmisons related flaws , bottom line is same amount of emissions for either.


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## Seasoned Oak

I have had good luck with the better GE model dehumidifier. The one that pumps the water up into an overhead drainpipe if needed. I have 2 of these in 2 different locations both work very well. One 2yrs old and one about 5 yrs or more old.  I like it around 55 to 60% . Only need to run it in the summer.


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## Sodbuster

Ashful said:


> Three years in a cool basement is not out of the ordinary for dehumidifier lifetime, today. They put such a small amount of refrigerant in them now, thanks to the EPA. It’s also why refrigerators no longer work in a cold garage, the refrigerant condenses and gathers in the coolest part of the system, and the compressor being much warmer doesn’t get any refrigerant, if there is so little in the loop. This leads to inevitable compressor failure.
> 
> I’ve always wondered about the environmental impact of throwing away entire refrigerators and dehumidifiers 4x more frequently than our parents, versus an extra few ounces of r438a, the majority of which will be reclaimed at end of product life.



My parents have a dehumidifier that is 20 years old and still plugging away. I purposely bought models that were designed for cold environments, down to 45 degrees. I can't spend $400 on dehumidifiers every 3 years, you are right engineers just build crap given the design parameters they are given. I'm temped to look for an older one at a  garage and have my buddy fix it for me if it breaks. Or I'll see if he can rig these two to run all the time, and I'll connect them to timers.


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## Ashful

Sodbuster said:


> My parents have a dehumidifier that is 20 years old and still plugging away. I purposely bought models that were designed for cold environments, down to 45 degrees. I can't spend $400 on dehumidifiers every 3 years, you are right engineers just build crap given the design parameters they are given. I'm temped to look for an older one at a garage and have my buddy fix it for me if it breaks. Or I'll see if he can rig these two to run all the time, and I'll connect them to timers.



The cold weather models will definitely do better, if the issue I’ve described above is your cause of death. But no engineer wants to design crap, we all want to design Ferrari’s, that’s why we got into this business. But the market won’t let us, there are 10,000+ customers who will only buy the cheapest crap available, for every one Ferrari customer.  The free market is a cruel mistress.


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## Sodbuster

Ashful said:


> The cold weather models will definitely do better, if the issue I’ve described above is your cause of death. But no engineer wants to design crap, we all want to design Ferrari’s, that’s why we got into this business. But the market won’t let us, there are 10,000+ customers who will only buy the cheapest crap available, for every one Ferrari customer.  The free market is a cruel mistress.



I'm not blaming the engineers, I am blaming the bean counters, upper management, and the EPA. I'm am positive that the engineers shake their head when asked to make product cheaper, knowing full well that the product will fail just beyond warranty. If they were given free reign to build a dehumidifier, using all of their preferred components, including refrigerant, they could and I doubt it would cost that much more. It might be a we bit less efficient, but that's for the consumer to decide.


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## Seasoned Oak

Im happy with my 2 GEs .        Paid $199  @ for 70 pint per day model with pump feature.  
In general i have to say iv been very pleased with every GE appliance iv ever owned. Our family top of the line GE washer goes through a punishing  daily schedule and is still plugging away after about 6 yrs.  More and more of my appliance choices are GE  but now that they have sold their appliance division all bets are off.


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## firefighterjake

Seasoned Oak said:


> Im happy with my 2 GEs .        Paid $199  @ for 70 pint per day model with pump feature.
> In general i have to say iv been very pleased with every GE appliance iv ever owned. Our family top of the line GE washer goes through a punishing  daily schedule and is still plugging away after about 6 yrs.  More and more of my appliance choices are GE  but now that they have sold their appliance division all bets are off.



After buying a replacement GE microwave which was an updated version of the microwave we bought a few years back and going through the hassle of the overly complicated installation I doubt I will ever buy another GE appliance. The microwave itself has been fine --both the old and new model. My real issue was that it was an updated version of an under-cabinet mount (well actually over the stove) and the old bracket did not line up to the bolt holes for the new model which meant drilling three new holes in my cabinets -- two of which were very close to the old holes. Add in a missing screw, a template which did not line up to anything and a few other issues which turned a potential half hour job into a half day job . . . I was not a satisfied customer.


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## brenndatomu

Kiotick4010 said:


> Best thing we did was to install a hybrid heat pump water heater to replace our old electric water heater.
> 
> It allowed us to get rid of the dehumidifier. The basement air is dry, with no musty smell.


Getting ready to do this myself...have the HPWH already, just need a spare minute to install it!


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## Qvist

Below 60% for mold.


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## Seasoned Oak

firefighterjake said:


> After buying a replacement GE microwave which was an updated version of the microwave we bought a few years back and going through the hassle of the overly complicated installation I doubt I will ever buy another GE appliance. .


And i was thinking of GE for my over the range Micro hood. The cheap ones wear out in 2 to 4 yrs. Im on my 3rd over the range micro already. Didnt try a GE there yet .  My service guy will only work on GE and Whirlpool and other american brand appliances.


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## fbelec

randy i can tell you from experience ge  is the way to go. all the others are made by whirlpool they don't last more than 5 or 6 years. ge microwaves last with any of my customers that have them and mine is 13 years old and going strong. used daily. my last was a ge and the only reason i got rid of it was the door handle broke and i couldn't figure out how to remove it and that was running on 12 years old


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## Seasoned Oak

fbelec said:


> randy i can tell you from experience ge  is the way to go.


I have a top line GE washer and it has been great. As are 2 GE dehumidifiers.  My best Experience with appliances have been GE,  Kenmore & Maytag . Have a Maytag dryer for 20 yrs and still going strong.   Worst experience has been Frigidaire and LG.


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## Sodbuster

Seasoned Oak said:


> I have a top line GE washer and it has been great. As are 2 GE dehumidifiers.  My best Experience with appliances have been GE,  Kenmore & Maytag . Have a Maytag dryer for 20 yrs and still going strong.   Worst experience has been Frigidaire and LG.



I have 2 frigidare  dehumidifiers that are complete garbage, inside of two years.. I bought one for my main basement and another for a small room  in my basement. They both stopped running and showed an error code, in two years time. I think my parents still have the same dehumidifiers from when I was a kid. Isn't being green great?? They use a lot less energy when their not working properly. That's $400 right down the crapper.


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## Ashful

Sodbuster said:


> I have 2 frigidare  dehumidifiers that are complete garbage, inside of two years.. I bought one for my main basement and another for a small room  in my basement. They both stopped running and showed an error code, in two years time. I think my parents still have the same dehumidifiers from when I was a kid. Isn't being green great?? They use a lot less energy when their not working properly. That's $400 right down the crapper.


My line of work often has me working alongside refrigeration engineers and technicians, and so when one of my refrigerators would malfunction, their brains were right there ready for me to pick for information.  To condense the issue of the EPA’s influence on residential refrigeration appliances, which would include dehumidifiers, down to one simple concept:  They have vastly reduced the amount of refrigerant used in an appliance of a given class and size.  The result is that, because the refrigerant tends to condense and pool into the coldest part of the system, the pump sometimes starves and either temporarily fails to cool, or eventually completely fails due to lack of lubrication.  The classic scenario is the garage refrigerator which fails to cool when the garage gets cold, all of the refrigerant is pooled outside the ice box in the condenser, and the constantly-running starved pump actually conducts heat to the evaporator, which in turn turns your refrigerator into an easy-bake oven.  Do this a few times, and it will cost you more in groceries than the price of a new refrigerator.

I haven’t specifically asked about dehumidifiers, but having had several stop working on cold days in my basement, and then magically recover when it gets warmer, I suspect they must have a similar issue.


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## tadmaz

FWIW, my small Danby dehumidifer from Menards is from 2013-ish and is doing great.

I fixed a gutter issue a couple years ago but I am suspecting that it take a few years before my storage area underneath my concrete porch will stop getting humidity?  Soil several feet down probably still has more moisture than it should?  One of these days I will rent a FLIR as well.


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## firefighterjake

I had a bad experience with a over-the-range GE microwave. 

The original microwave wasn't bad . . . but after six or seven years it finally gave up the ghost. The handle had broken on it before that, but I fixed this with a bit of super glue.

When looking for a replacement microwave I figured I would go with a GE microwave -- same make, similar model . . . just an updated version. My thinking was I would be able to use the same mounting hardware. 

That was my first mistake. Mounting hardware was just a bit different . . . just enough so that I had to drill new holes in my cabinet.

Here's my review I posted at Lowes . . .

--

Only two days in . . . so this review isn't all that comprehensive in terms of how well this microwave works, how reliable it is, etc.

The good: I can tell you it is similar to our old GE microwave and the vent is much, much quieter and the light is much, much brighter. Nice improvements over the old microwave. 

The question: The verdict is still out on the door as it feels a bit flimsy. In the store I noted that both of the GE models' doors did not open/close as nicely as other makes/models on display. On our old GE microwave the handle broke and the paint peeled on the door, so I'm watching this model carefully.

The bad (i.e. the installation): To be honest while I often read reviews, I rarely write them . . . especially on something like a microwave. However, I felt compelled to write this review as my wife and I have never had such a challenging time installing this microwave.

I should mention that we are not professionals, but we have remodeled much of our house, including doing a complete renovation in the kitchen (doing pretty much everything but installing the granite counter tops). I would like to think we are not complete idiots when it comes to working on something like this, but this project proved to be a very long and frustrating experience.

First off, why would GE build a microwave with a different mounting bracket from their older models? One of the reasons we purchased a second GE microwave was in the hopes of re-using the same bracket so we could avoid more work and more importantly avoid drilling more holes in the cabinet. Unfortunately, the new microwave/bracket's tabs and bolt placement were off by a bit which meant the old bracket had to come down and the new bracket installed. Next time we may just as well go with any brand if one cannot re-use the same bracket. As it is, we ended up having to use washers with the cabinet bolts since two of the three holes were literally one inch from the old holes and didn't leave a lot of wood to support the weight of the microwave.

The template: I don't know if we were reading this wrong, but we read and re-read the directions to use the template for a recessed cabinet mount and no matter what we did the template would not match up. In the end, the template proved to only be useful to light a fire. We finally gave up and took detailed measurements with a tape measure to figure out where to drill the holes.

Even simple things like installing the charcoal filter on this microwave was a challenge. I thought for sure I was going to snap the plastic grill on the top as it came out only after I applied quite a bit of force. It was here that my wife wondered why GE didn't simply ship the microwave with the filter already installed. Meanwhile, I was wondering a) why the picture in the directions showed a location of a screw where there was no screw and b) what was the engineer of this microwave thinking when they came up with a design where you have to remove three cabinet bolts, tip the microwave towards you, remove two screws and then pry off the grill piece to change a filter every six months or so (seriously . . . the directions recommend you do all this to change out the filter).

I'm not sure if GE has a quality control program in place or if someone was simply having a bad day. Since we don't have ductwork we needed to rotate the blower motor to set it up as a recirculating system. Not a problem. Removed the cover. Removed the screws. Rotated the blower motor and then went to re-install the two screws . . . only to discover one of the screw holes was literally twice the size as the screw. I checked and re-checked, thinking perhaps I was supposed to put in a larger screw . . . or maybe I was supposed to use a different screw location. Nope. This still boggles my mind as to how this slipped through.

Finally, microwave was installed. Plugged in . . . and that's when I noted two "ripples" in the sides of the microwave. Now, to be frank, it's not a huge deal to me. I am a function over form sort of guy, but I guess you could say this was simply the last straw that made me decide to write this review.

In hindsight, at least in terms of the installation and first impressions, I wish we had waited and ordered a different make/model. We opted to buy this GE since it was in-stock and we were hoping to re-use the same bracket. Maybe I'll be pleased and this microwave will last a very long time . . . but I am not holding my breath. Next time I highly doubt we'll be buying a GE based solely on this challenging installation and first impressions of the microwave. 

---

The good news is that we installed it in June of last year and it's still working.


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## Seasoned Oak

I had the same experience with a magic chef same model a few years newer. Holes were just off enough that they were too close to the old holes. I figuered if i got a better quality Micro range hood i wouldnt have to change it out so often.


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## Sodbuster

Seasoned Oak said:


> I had the same experience with a magic chef same model a few years newer. Holes were just off enough that they were too close to the old holes. I figuered if i got a better quality Micro range hood i wouldnt have to change it out so often.



Lol, we have a toaster oven that is at least 25 years old. The handle broke, so my wife wanted a new one. I used epoxy to repair the handle and it's held ever since. She still cranks about it, and wants a new one, but I tell her, "does it make toast?" works the same as a new one.


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## tlc1976

My basement is bare concrete floor and block wall. Water seeps in slowly during summer and fall at the base of the walls so there is a water channel on the perimeter that leads to a sump pump.

I keep it at 45-50% which is about as low as it goes. Makes it hard for spiders and things to want to visit. I’ve gone without one and once it gets to about 70% the pipes start dripping and all my books and papers start getting moist. Which would probably turn to mold if left like that.

I keep the door and windows closed otherwise I’m essentially dehumidifying the outside which is a losing battle. With it closed up it stays nice. It adds maybe $20 to my bill but I’m also not running the pellet stove and extra lights so it’s a wash. In the winter it never runs.

When I moved in there was a soleus that was on its last leg. Going by the date of manufacture it lasted a year and a half. I then spent $200 on a ge from Home Depot which also lasted a year and a half. Each time the coils rusted out. So this time I got a danby from abc warehouse for $200 plus $60 for a 5 year warranty. So if I stay on my track record I’ll get a free one long before warranty is up. And if it lasts 5 years then I’m still 3 units ahead. A win win. So far it’s been just over 2 years and it’s still running fine as it did kick on a bit a week or two ago when it got warm.


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