# Kuuma Installation Question



## DaveH (Mar 1, 2015)

I am seeking some opinions about a Kuuma VF 100 install.  Putting it in this corner would be necessary to get it next to the hot water and hook up the H2O coil.  I've read the unit does not radiate too much heat, but that is my verizon service line and the direct tv cables on the wall.  I intend on cleaning them up before install, but does anyone think it would be too close to the heat?  The chimney will likely be exiting the house to the right, along the same wall as the door.  The yellow line is also my propane, I think that is far enough away.  Worst case would be I put the furnace along the wall by those outlets and move the HW tank into the corner next to it.


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## brenndatomu (Mar 1, 2015)

If you respect the clearances that Kuuma recommends you should be fine. 
What's the plan for a chimney, class A out through the wall?


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## DaveH (Mar 1, 2015)

brenndatomu said:


> If you respect the clearances that Kuuma recommends you should be fine.
> What's the plan for a chimney, class A out through the wall?



Yes, class A through the wall to the right.


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## STIHLY DAN (Mar 1, 2015)

You will have no issues at all putting it anywhere in the corner. However I would suggest getting a cheap electric water heater and use it as a tempering tank to your heater. You will get much more hot water from your wood. And if you raise it, that would be even better.


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## velvetfoot (Mar 1, 2015)

Hi Dave, fellow Rensselaer Countyite!
I don't have any experience with forced air but I find it interesting nonetheless so I'll chime in anyway.
I'd think you want to make sure you have a nice short tie in to a chimney that's in a good place on the outside of the house (it's going to be a new chimney, right?)  The chimney seems to drive a lot of other stuff.
There's also integrating the duct work into the existing system-short too?  
You want to leave room for maintenance-the work flow involving the wood and ash removal, cleaning the unit as well as the venting.
I'm sure the manual has stuff to say about all this too.
I have no idea about water tank location, but I'd think if a circ pump was involved there'd be no problem in locating it where you want.


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## cityboy172 (Mar 1, 2015)

Replace the pressure relief valve on you water heater before you have  a problem.


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## DaveH (Mar 1, 2015)

velvetfoot said:


> Hi Dave, fellow Rensselaer Countyite!
> I don't have any experience with forced air but I find it interesting nonetheless so I'll chime in anyway.
> I'd think you want to make sure you have a nice short tie in to a chimney that's in a good place on the outside of the house (it's going to be a new chimney, right?) The chimney seems to drive a lot of other stuff.
> There's also integrating the duct work into the existing system-short too?
> ...



It will be a new chimney and the furnace will be as close as i can get it to the wall.  I got a quote from Matchless for the chimney plus install, not cheap, but it was about what I was expecting.  The furnace is coming in the next week or two, and it looks like all this snow will start melting finally.  I might end up waiting for mud season to end in order to get the unit from the garage to basement, so I have time to make the last minute plans.


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## DaveH (Mar 1, 2015)

cityboy172 said:


> Replace the pressure relief valve on you water heater before you have a problem.



Because of the wet floor or the build up? I grabbed some water out of it before the picture was taken, thats why the floor is wet.


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## cityboy172 (Mar 1, 2015)

DaveH said:


> Because of the wet floor or the build up? I grabbed some water out of it before the picture was taken, thats why the floor is wet.


The build up causes the issues. You'll get build up under that seat, and it won't reseal. Thats also a pretty bad / dangerous habit to be manipulating a T/P valve.


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## velvetfoot (Mar 1, 2015)

DaveH said:


> It will be a new chimney and the furnace will be as close as i can get it to the wall.  I got a quote from Matchless for the chimney plus install, not cheap, but it was about what I was expecting.  The furnace is coming in the next week or two, and it looks like all this snow will start melting finally.  I might end up waiting for mud season to end in order to get the unit from the garage to basement, so I have time to make the last minute plans.


Yeah, my general impression is that Matchless is not cheap but good.  They do duct work too, I guess?
I hired a guy with a biggish skid steer with tracks and forks to move the boiler from the garage to the basement-it made some impressions in the lawn that seem to have gone away, but it was June.  Are you responsible for moving into the basement?  I wonder if you could do something while the ground is still hard, albeit snow-covered?
I'm sure they're professionals, but I, myself, drilled a couple of 4" holes for a relocated oil tank through the concrete wall with a rented core drill and it turned out great, so I assume they're going to drill a hole too.


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## DaveH (Mar 1, 2015)

velvetfoot said:


> Yeah, my general impression is that Matchless is not cheap but good. They do duct work too, I guess?
> I hired a guy with a biggish skid steer with tracks and forks to move the boiler from the garage to the basement-it made some impressions in the lawn that seem to have gone away, but it was June. Are you responsible for moving into the basement? I wonder if you could do something while the ground is still hard, albeit snow-covered?
> I'm sure they're professionals, but I, myself, drilled a couple of 4" holes for a relocated oil tank through the concrete wall with a rented core drill and it turned out great, so I assume they're going to drill a hole too.



My neighbor has a HVAC company, so I'll talk to him about the duct work.  I haven't spoken to the shipping company yet directly, but I assume they will dump it in the driveway and I am responsible for the rest.  If I can get the furnace to the basement while the ground is still frozen I will.  I will probably get a skid steer over here to move it but I'm traveling the next couple weeks so I'll have to see what the weather does. I have a bit of a grade down to the basement so I don't wanna see my investment go sliding down the hill.  

They would drill through the wall.  It doesn't seem worth it to rush the install this year, hopefully the worst of it is over, so im gonna keep shopping and recruit friends to help with the install. The insurance company prefers a professional so that might force my hand.   The price for parts estimated by Matchless was cheaper that what I looked at online, on build your own websites.  The $1100 install fee was tough to swallow.


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## STIHLY DAN (Mar 1, 2015)

And a Prefab chimney is easy to install. Start to finish mine was 3 hours.


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## velvetfoot (Mar 1, 2015)

Here's a picture of last June.  It will get warm and sunny again.


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## brenndatomu (Mar 1, 2015)

You can get Selkirk Supervent at Menards, everything you'd need to build a class A chimney for $821 (plus shipping since there are no big green Ms around you) and like Stihly says, it's easy to install. Agree with VF, rent a core drill, perfect hole through the foundation in no time!
Chimney parts...
http://www.menards.com/main/store/2...rod_Tech_Spec/combinedBuyersGuidetechdata.pdf
1. Through the wall/support kit, $291.09 
2. 6" x 36" (x 6 for 18' chimney) $449.94
3. Wall bands (x 3) $44.25
4. Lock bands (x 6) $35.94
-------------------------------------------------------
Total $821.22, at regular store prices (+ tax)

If you have snow on the ground right now I'd get that bad boy in there before it melts. It will minimize damage to the yard, especially if the ground is froze too. I had to dig up someones yard to repair a leaking water line last week. The yard was a swamp from the leak but I was able to get the hoe close enough to dig and still stay on snow/frozen ground. I piled the dirt (slop!) on the snow and was able to swipe it back in the hole with the hoe bucket when done without ever exposing the grass. It started snowing shortly after and in a couple hours you couldn't even tell anything had been done except for the backhoe tracks in the snow. If that leak had been in the springtime it would have required some serious landscaping afterwards!
Another idea is to use the snow to your advantage, make a sled. Sheet of plywood or steel roofing, you'd might be surprised how easily it will move that way!
Like mentioned above, mount your tempering tank (or water heater, whatever you use) as high as possible, it will make the gravity flow work better.
My 2 cents...


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## brenndatomu (Mar 1, 2015)

Oh, and try to keep the placement of the furnace such that you can use 45* elbows on the stove pipe over to the chimney connector instead of 90s, it will greatly improve draft and much less (probably none) smoke rollout when you open the loading door


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## DaveH (Mar 1, 2015)

brenndatomu said:


> Oh, and try to keep the placement of the furnace such that you can use 45* elbows on the stove pipe over to the chimney connector instead of 90s, it will greatly improve draft and much less (probably none) smoke rollout when you open the loading door



I was planning on this and was concerned it would make cutting the hole through the wall myself a little trickier.  I guess I'd have to estimate the angle in order to have the pipe exiting the wall at the 45.


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## velvetfoot (Mar 1, 2015)

He might have meant minimize the right angles, not go through the wall at a 45.


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## DaveH (Mar 1, 2015)

got it


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## Smoke Signals (Mar 1, 2015)

DaveH said:


> I am seeking some opinions about a Kuuma VF 100 install.  Putting it in this corner would be necessary to get it next to the hot water and hook up the H2O coil.
> View attachment 154942
> View attachment 154941



I didn't think a water loop was allowed in the fire box on the Kuuma? How do you plan to install the coil? in the duck work?


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## DaveH (Mar 1, 2015)

They make a H2O coil option.  Preheats water entering HW tank, or tempering tank.  There isn't many pictures or detailed descriptions on the website.  People here seemed happy with it on this site so I figured it was worth a shot.


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## Smoke Signals (Mar 1, 2015)

Oh cool, is this new? I thought I asked about this one time and they told me they didn't have this option. Regardless, I'm glad to hear they do. A Kuuma is in my long term plan and I thought I was going to have to do with out DHW from wood. Guess not, good news!


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## brenndatomu (Mar 1, 2015)

velvetfoot said:


> He might have meant minimize the right angles, not go through the wall at a 45.


Yes, this ^ ^ ^. Yeah, the chimney tee goes outside the wall and a 1' piece of class A pipe goes through the wall to the inside with a stove pipe adapter (or chimney connector) on the end. Which makes me realize that I forgot that part on my parts list earlier, I think the 1 footers are $45 or so.


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## DaveH (Aug 16, 2015)

Kuuma has made it into the basement.  Skidsteer got it in with no damage besides some ruts in the yard.  The chimney is going in soon and now I have to get the hot water tank situated for the H2O coil.  I like the sounds of the stone lined tanks but not the $1200 price tag.  I have a 40 gallon electric water heater now that is 8 years old and I was thinking about getting a new one, spend maybe $500, and using the old one as the tempering tank.  Anybody do anything different?


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## STIHLY DAN (Aug 16, 2015)

If you get a new electric tank, seriously think about it being a heat pump water heater. save a ton of cash over the years.


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## sloeffle (Aug 19, 2015)

STIHLY DAN said:


> If you get a new electric tank, seriously think about it being a heat pump water heater. save a ton of cash over the years.


I couldn't agree with you more. My HPHW costs me about one-fourth of what it cost me to run my Marathon.



DaveH said:


> I like the sounds of the stone lined tanks but not the $1200 price tag. I have a 40 gallon electric water heater now that is 8 years old and I was thinking about getting a new one, spend maybe $500, and using the old one as the tempering tank. Anybody do anything different?


Have you looked at Marathon ? They are plastic and have a lifetime tank warranty.


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## DaveH (Aug 19, 2015)

sloeffle said:


> I couldn't agree with you more. My HPHW costs me about one-fourth of what it cost me to run my Marathon.
> 
> 
> Have you looked at Marathon ? They are plastic and have a lifetime tank warranty.



After researching HPHW I think I'm sold on them.  I wish some of the less expensive models had better reviews, but the Stiebel Eltron seems to be the only bullet proof model.  The GE model has had problems it seems, that may or may not have been worked out.  There is a $400 rebate in Upstate NY from the power company, so that helps take the sting off.  The 80 gallon model is sold at home depot, but I cant find where to by the smaller unit.


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## sloeffle (Aug 19, 2015)

I got an AO Smith Voltex 50 gallon for the same price they are selling the GE's HPHW here in Ohio for. The AO Smith has a 10 year warranty. @woodgeek has had the 80 gallon model for a few years without that many issues from what I can recall.


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## brant2000 (Aug 20, 2015)

cityboy172 said:


> The build up causes the issues. You'll get build up under that seat, and it won't reseal. Thats also a pretty bad / dangerous habit to be manipulating a T/P valve.



Respectfully, I'm not sure that I agree.  Just like is done with high pressure boilers, I think it's a good practice to exercise relief valves.  Otherwise, they may not work when they need to.


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## STIHLY DAN (Aug 20, 2015)

DaveH said:


> After researching HPHW I think I'm sold on them.  I wish some of the less expensive models had better reviews, but the Stiebel Eltron seems to be the only bullet proof model.  The GE model has had problems it seems, that may or may not have been worked out.  There is a $400 rebate in Upstate NY from the power company, so that helps take the sting off.  The 80 gallon model is sold at home depot, but I cant find where to by the smaller unit.



They fixed all the GE problems with the manufacturing moved to the us. Have had mine for 3 years and no issues. They also have a 10 year warranty. If you can fit and afford an 80 gal go with that.


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## DaveH (Aug 24, 2015)

STIHLY DAN said:


> They fixed all the GE problems with the manufacturing moved to the us. Have had mine for 3 years and no issues. They also have a 10 year warranty. If you can fit and afford an 80 gal go with that.



Do you use the H2O coil on the Kuuma?  I spoke to Steibel Eltron rep about using pre heated water with the HPWH and they said it isn't preferred.  I'd guess the savings would be bigger not using the $200 coil (if I couldnt use it), and buying a HPWH then using the coil and a traditional water heater.  

I heard the GE problems were caused by Chinese manufacturing.  Good to hear they moved it here.  They are an option for me.  

Chimney going up tomorrow, then I can start hook up of duct work and electrical.


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## STIHLY DAN (Aug 25, 2015)

I do have the coil on mine. I use an 80 gal unplugged electric water heater as a tempering tank, that feeds the hpwh.


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## DaveH (Aug 25, 2015)

STIHLY DAN said:


> I do have the coil on mine. I use an 80 gal unplugged electric water heater as a tempering tank, that feeds the hpwh.




 Thanks.  Steibel Eltron rep said cold water at the bottom of the tank helps the R134 refrigerant turn from a hot gas back into a liquid to restart the process.  If it works for you i might give it a try.


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## DaveH (Aug 25, 2015)

Chimney is in.  Furnace is in place.  Duct work scheduled.  My concern now is again hot water.  Installer is questioning the use of a tempering tank.  He wants to hook the H2O coil right up to the current water heater.  I am likely getting the tank but will either way work?


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## STIHLY DAN (Aug 25, 2015)

Its hard to heat hot water when its already hot. Greater the temp difference, better the heat transfer.


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## DaveH (Sep 4, 2015)




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## JRHAWK9 (Sep 4, 2015)

DaveH said:


> Installer is questioning the use of a tempering tank.  He wants to hook the H2O coil right up to the current water heater.  I am likely getting the tank but will either way work?



Last summer when I installed my Kuuma a local plumber was also looking at me sideways when telling him how I wanted the old 40 gal electric water heater I had connected between my coil and water heater...lol  I decided to do it all myself.  Saved a lot of $$ as well.


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## brenndatomu (Sep 4, 2015)

Looks good. What size is you return air duct there...looks like a single 8"?
EDIT: Never mind, I just seen the second pic, 12" pipe?


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## begreen (Sep 4, 2015)

The ducting looks undersized. The VaporFire 100 has a 24x24" supply plenum. Looks like it is being restricted quite a bit. Supply looks to be about 8" x 24" or 192 sq in.  The return if 12" round is about a fifth of the supply plenum size and much smaller than the supply duct. Restrict it too much and the blower may race due to too much static pressure. Also, this could be problematic during a power outage:
DUCTS SHOULD BE LARGE ENOUGH TO HANDLE GRAVITY AIRFLOW IN EVENT OF ELECTRIC POWER OR FURNACE FAN FAILURE (APPROXIMATELY180-200 SQ. IN.)


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## STIHLY DAN (Sep 4, 2015)

A few suggestions and questions. I agree with BEGREEN on the duct looking a bit undersized. Are there backdraft dampers installed? Also on the flue pipe you may want 1 45 and 1 90  instead of the 3 90's. When you pipe in the water heater using all 45's and no 90's will help with the thermo syphon. I also highly recommend a tempering tank. You are going to by happy with this, just needs a few tweak's.


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## DaveH (Sep 5, 2015)

I'll look into improving the duct work set up.


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## maple1 (Sep 5, 2015)

I'm not a furnace or hot air guy but I don't think that's the damper they're talking about.

I think they mean dampers in the duct work to make sure the air doesn't go opposite to the way you want, with more than one furnace in the equation?


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## DaveH (Sep 5, 2015)

maple1 said:


> I'm not a furnace or hot air guy but I don't think that's the damper they're talking about.
> 
> I think they mean dampers in the duct work to make sure the air doesn't go opposite to the way you want, with more than one furnace in the equation?



yes.  There are dampers installed in the duct work


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## STIHLY DAN (Sep 5, 2015)

manual or auto dampers?


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## DaveH (Sep 6, 2015)

STIHLY DAN said:


> manual or auto dampers?



manual dampers


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## STIHLY DAN (Sep 6, 2015)

Just make sure that when the Kuuma is running that the supply is not going through your gas furnace out the return back to the Kuuma. You will get no heat and hurt the Kuuma.


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## DaveH (Sep 12, 2015)

begreen said:


> The ducting looks undersized. The VaporFire 100 has a 24x24" supply plenum. Looks like it is being restricted quite a bit. Supply looks to be about 8" x 24" or 192 sq in.  The return if 12" round is about a fifth of the supply plenum size and much smaller than the supply duct. Restrict it too much and the blower may race due to too much static pressure. Also, this could be problematic during a power outage:
> DUCTS SHOULD BE LARGE ENOUGH TO HANDLE GRAVITY AIRFLOW IN EVENT OF ELECTRIC POWER OR FURNACE FAN FAILURE (APPROXIMATELY180-200 SQ. IN.)



I am a little small for duct work at 160 SQ inch.  All of my duct work was pre existing, so I would need a complete overhaul. I have a two story colonial, so considering the duct work in the walls aren't going to change I am limited in what i can do.   I am looking into a fresh air intake that the furnace can draw off of.  

As far as gravity flow during a power outage, I could replace the "stem" duct work but how much would that help if it fed to 8 by 20 duct work running vertically to the 2nd floor?


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## DaveH (Sep 12, 2015)

brenndatomu said:


> Looks good. What size is you return air duct there...looks like a single 8"?
> EDIT: Never mind, I just seen the second pic, 12" pipe?



EDIT : That is 14n.  I might have to fire it up to see if it needs a fresh air intake.  I half want the weather cool down so I can fire it up.


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## maple1 (Sep 12, 2015)

Not sure what the Kuuma specs but looks like your supply is restricted some - and your 12" return is 30% smaller than the supply. Not sure how all that will balance out since there are likely other factors involved.


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## STIHLY DAN (Sep 12, 2015)

You are choked down on supply, and really choked down on return. In order to make your unit work properly you need to do something with your ductwork. That is too nice a unit to burn up on an incorrect install. Maybe hire someone and give them the installation directions.


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## DaveH (Sep 13, 2015)

STIHLY DAN said:


> You are choked down on supply, and really choked down on return. In order to make your unit work properly you need to do something with your ductwork. That is too nice a unit to burn up on an incorrect install. Maybe hire someone and give them the installation directions.



The vertical return is 196 sq in.  The unit was installed professionally, of course it remains a work in progress.


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## maple1 (Sep 13, 2015)

My 30% guess was based on 12"dia. return. If it's 14", that would be 154 sq.in. So almost up to the 160" you mentioned for the supply. If I understood things correctly. But there would be other factors like restrictions in either. (Bends, etc.)

I'm over my head already here - so will watch how things progress. You might want to round up some temperature measuring gear to measure duct temps with, and maybe a manometer for flow balancing, for when you try it out & tune things up.

You certainly have a nice furnace - good luck!


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