Is an outdoor air kit really needed? Let me hear from you.....

[peirhead]

Many newer homes have a balanced air exchanger system that sucks in outside air and exhausts stale house air with various flavors of heat recovery systems. The balanced systems take into account changes on air pressure due to bathroom fans, dryers, furnaces and Pellet stoves..... and keep the house at a neutral pressure...If you have one of these system an OAK is probably not necessary. The idea is to manage where the fresh air comes from...preferably not cold drafts from around the windows!! The OAK is probably never a bad thing but unnecessary in many cases.

 

[sydney1963]

OAK, YES!

 

[Shane]

They're all that way, so were Whitfields.

So your saying Shane that ALL pellet stoves have a hole in the "OAK" tube that runs from the back of the stove to the firebox? I didn't know that.

Some have a closed system... Harman and Englander for example.

Using an OAK that just connects to the back cover is silly, imo. You may as well just crack a window.

No absolutely not, I was responding to macman about the Avalons and added that Whitfields are like that too. I know that there are several brands/models that have solid tubes.

 

[krooser]

Here's my OAK using Selkirk vent materials...

 

[ORiley]

My Avolon heats a 48' x 26' pole barn. No OAK here for two reasons; (1) I have enough fresh air "leaks" and (2) I want to take the humidity out of the air in early spring and late fall.

 

[sydney1963]

Here is what my OAK looks like. I have had it since day 1, so don't know what it would be like without it. Nice and warm, no drafty air around my feet.

 

[CenterTree]

Here's my OAK using Selkirk vent materials...

Please shed some light on the SELKIRK system, It seems to me that if the fresh air intake is so very close to the exhaust (at the end of the pipe) then wouldn't the exhaust (toxic) air be drawn IN with the good air. And if so, does it even matter since that air will be "used" and re-exhausted anyway?. I always thought it is best to have a certain DISTANCE between the exhaust and fresh intake. ANy comments?

 

[Shane]

Look at their website it's their direct vent system. Look at the components and install instructions and you'll see how it works.

 

[krooser]

Here's my OAK using Selkirk vent materials...

Please shed some light on the SELKIRK system, It seems to me that if the fresh air intake is so very close to the exhaust (at the end of the pipe) then wouldn't the exhaust (toxic) air be drawn IN with the good air. And if so, does it even matter since that air will be "used" and re-exhausted anyway?. I always thought it is best to have a certain DISTANCE between the exhaust and fresh intake. ANy comments?

No idea... all I know is this is the system my dealer sells the most of and it's an EZ install.

I had never done any comparison shopping for my pellet vent materials. I bought my used St Croix from ESES and also the vent kit. The pieces I didn't use from the kit they bought back... a good deal IMHO.

 

[jimcooncat]

The instructions told me to make the OAK as straight as possible. But now I'm getting condensation on it, and the drip is going onto my hearth pad. I'm going to have to keep this mopped up or I'll get rust on my stove base! Anyone else in this situation? Is there a better way to do this, maybe make a dip in the OAK so it will drip from the middle rather than near the stove?

Check it out:
(broken image removed)

 

[Shane]

I would think that a slight bend wouldn't hurt much. If you want to make sure, you could call the tech dept or the stove dealer.

 

[oconnor]

The instructions told me to make the OAK as straight as possible. But now I'm getting condensation on it, and the drip is going onto my hearth pad. I'm going to have to keep this mopped up or I'll get rust on my stove base! Anyone else in this situation? Is there a better way to do this, maybe make a dip in the OAK so it will drip from the middle rather than near the stove?...

Insulate and wrap the pipe airtight. You will only get condensation if there is s temp differntial between the surfaces - so a few wraps of insulation would help, and some sort of vapour barrier - BUT -

Remember it is near heat, so non combustibles please. Think rockwool and foil with foil tape.

I had an energy advisor last week tell me he has seen condensation issues that have actually rusted the air inlet off the stove, so you want to avoid that.

 

[oconnor]

I am CONFLICTED concerning OAK (Outside air kit/Outside Combustion Air etc) - here is my problem

The science behind why an OAK is a good idea makes perfect sense to me. I have recommended it to many on here, especially when they have depressurisation issues on a basement install - I wish that my old stove in our previous house had one installed - I likely would not have filled the house with smoke when the flue reversed one cold day. It essentially removes the firebox from the effects of depressurisation,

EXCEPT

The science behind why an OAK can be a problem makes sense also - see (broken link removed to http://www.woodheat.org/outdoorair/outdoorair.htm) for the details . The Woodheat site is the main source of info on the negative side of OAK installs - his main point is that wind effect can generate enough negative pressure on the downwind side of a house to overcome the draft of some flues when operating EPA stoves.

So who is "he"? John Gulland is a well respected authority on wood heat issues, and was a big force behind having mandatory OAK removed from the National Building Code in Canada. His concerns surround pressure issues and wind effect creating the POTENTIAL to overwhelm flue draft and reverse the flue. Here is his Hearth.com wiki https://www.hearth.com/econtent/index.php/wiki/John_Gulland/ . Some addition comments on the issue of OAK from Mr Gulland can be found here : Yahoo Groups - Woodheat - OAK discussion. It is a good read - even those who are very pro OAK should review it, as you need to be able to address the concerns he raises in a logical fashion to counter them if you think they are wrong. For now, I just don't know. I am not a scientist nor engineer.

So, in the end, I am inclined to not install an OAK on my stove, as I don't have draft issues when cold, nor do I have drafts in my house that are aggrevated by indoor air being vented out my flue. Given that the loss of air from within the envelop of a house as a result of burning an EPA stove is REALLY LOW (in the order of 10-50 CFM, depending on your source - which is less than your bath fan), I am likely to spend my skills and money on other ways of keeping heat in my house/keeping outside air out of my house, like a block off plate (still not done that yet).

If I did have issues that an OAK can relieve, like spillage or cold hearth syndrome or flue reversal, then I would truly look at installing one, but I would have to re-read the issues John raises, and consider how to avoid the wind effect issues he raises.

I have not read any folks who installed an OAK who didn't say it worked well, but I haven't read much from folks who spend time and money on solutions who anectodatlly report that they wasted thier time and money. That said, I haven't read of any of the disasters that John predicts actually occuring (I haven't read everything mind you), so to me, I am still conflicted.

Like any tool, I think that an OAK is good at some things, and can have some issues - but burning wood has issues too, and I do that.

If anyone has read anything on actual OAK malfucntions, I would love to know.

 

[marksav]

An OAK is not needed BUT cold air will be pulled into the building to feed the stove. From what I have been told with an OAK the cold outside air makes the stove burn more efficiently (like you read from herman), More BTU for your buck. New high efficiency furnaces require the OAK to meet the ratings.

As for the condensation problems, the room where the stove is located has to be humid. Warm humid air coming in contact with the cold intake will create condensation similar to you getting into your car on a cold rainy or snowy day and turning on the heat and the windows fog up from the water evaporating. Insulation sounds like a good idea but like said earlier remember the temps the stoves get to.

Please feel free to correct me if I am wrong.

 

[bungalobob]

OAK may not be needed, but everyone in my house suddenly notices less cold drafts near windows and doors. That has got to a plus. When the oil furnace was running it was always cool and drafts were throughout the house. Now with the pellet stove, the drafts are minimal or non-existent. So preferred is my opinion.

 

[Devo]

I am CONFLICTED concerning OAK (Outside air kit/Outside Combustion Air etc) - here is my problem

...The science behind why an OAK can be a problem makes sense also - see (broken link removed to http://www.woodheat.org/outdoorair/outdoorair.htm) for the details . The Woodheat site is the main source of info on the negative side of OAK installs - his main point is that wind effect can generate enough negative pressure on the downwind side of a house to overcome the draft of some flues when operating EPA stoves.

So who is "he"? John Gulland is a well respected authority on wood heat issues...

The article only addresses stoves and/or fireplaces that use the stove's heat to create the draft. A pellet stove has a combustion air fan which pressurizes the flue. Big difference.

If the wind overcomes the pressure created by the combustion air fan in a pellet stove, you probably have bigger problems.

 

[oconnor]

The article only addresses stoves and/or fireplaces that use the stove's heat to create the draft. A pellet stove has a combustion air fan which pressurizes the flue. Big difference.

If the wind overcomes the pressure created by the combustion air fan in a pellet stove, you probably have bigger problems.

You are correct.

Somehow, I thought I was in the Hearth Room when this post started, and now I'm in the Pellet Mill.... Toto, we aren't in Kansas anymore. These guys use electricity to burn thier wood. I'm not sure what my friends over there would say if they found me hanging out with you guys....(LOL)

Sorry for the crossover post. That said, Gulland does seem to be a lone voice on the side of seeing problems with OAK on natural draft appliances. Are there any other voices out there that support his POV?

 

[Devo]

... That said, Gulland does seem to be a lone voice on the side of seeing problems with OAK on natural draft appliances. Are there any other voices out there that support his POV?

I agree with him. I exchanged emails with him a few years back about the topic.

 

[krooser]

I would think that a system like my Selkirk vent would eliminate any condensation since the outside air is being drawn into the house AROUND the warm exhaust vent...

I must say that my home was very drafty with my gas furnace... it's in the basement and draws air from the basement. I'm no expert on this stuff but I believe I have fewer drafts with my pellet stove.

 

[rayttt]

Presently I dont have an OAK installed but I am thinking about it.
I have cold floors..and my feet are often cold...My pet bird Im sure is feeling the cold
as he walks across my living room...but hes not talking
I put my thermometer on the floor and its 10 degrees colder than the room temp 72 and 62 on floor.
the cold draft on the floor has to be coming from some where...presumably from the other rooms where its colder.
the OAK should stop this..but then wont the other rooms not get as warm because theres no cold air removal so no
heated air replacement??

 

[Devo]

Presently I dont have an OAK installed but I am thinking about it.
I have cold floors..and my feet are often cold...My pet bird Im sure is feeling the cold
as he walks across my living room...but hes not talking
I put my thermometer on the floor and its 10 degrees colder than the room temp 72 and 62 on floor.
the cold draft on the floor has to be coming from some where...presumably from the other rooms where its colder.
the OAK should stop this..but then wont the other rooms not get as warm because theres no cold air removal so no
heated air replacement??

Where ever the cold air is coming from, it's coming from outside. IF the air is coming from another room, installation of an outside air kit may (or may not) make the other room warmer.