Wood stove and backdraft

[begreen]

Where do folks usually get theirs? The stove is only for my finished basement which is my office I work in 5 days a week

Normally one gets the wood from a wood supplier. This can be either a place that is dedicated to firewood supply or a tree company that does it as side work. Hardwood takes 1-2 yrs to season. Full-time burners are usually 2-3 years ahead on their wood supply for this reason. This could be 4-8 cords of wood stacked under a top cover or in a shed. Beware of sellers that claim the wood is seasoned. 90% of the time it is not. Firewood does not dry well in tree-length form. It needs to be split and stacked to dry thoroughly. In the short term, you may need to buy kiln-dried wood. Do a google search for firewood suppliers in your area.

The stove will heat more than just the basement. A lot of the heat will convect up the large open stairwell next to the stove location.

 

[Casadecorgz]

I'm not familiar with this unit, but the specs show it is a dual-motor design that will permit proper balancing.

Awesome! I just sent the chimney liner installer a friendly but matter of fact email explaining he needs to come back to install the tee cap.

I’m going to check out some wood stove stores near my house with my wife tomorrow

 

[Winterpeger]

I got a renewaire ERV, what things should I be aware of when they’re installing it?

That the unit is balanced, whatever cfm is being exhausted has to be drawn in on the fresh air side. The HRV/ERV should not be installed to change home pressurization.

 

[begreen]

Slight positive pressurization to correct a negative pressure zone to neutral pressure is ok. This has solved drafting issues for tough cases.

 

[Winterpeger]

Slight positive pressurization to correct a negative pressure zone to neutral pressure is ok. This has solved drafting issues for tough cases.

With this caveat

 

[begreen]

With this caveat

Yes, the installer needs to know what they are doing. The caveat is for excessive positive pressure. There is another caveat right above that one-

Combustion and flue gases from heating appliances must
never be allowed to enter living spaces.
ERV/HRV unit must be properly balanced to prevent
negative pressure in structure. Negative pressure can
cause back−drafting of combustion gases in other
household appliances such as Gas Furnaces, Oil
Furnaces, Hot Water Heaters, Wood Stoves, Fireplaces,
etc.

 

[Winterpeger]

It’s not the proper way to correct pressurization issues but will defer to your knowledge.
"Balanced"

 

[bholler]

It’s not the proper way to correct pressurization issues but will defer to your knowledge.
"Balanced"

So what is the proper way to correct pressure issues?

All instructions talk about balancing the system. In some cases that will mean adding pressure to the house with the unit so the house is properly balanced. That means either neutral or slight positive pressure.

 

[Winterpeger]

That is what some don’t understand the HRV system its self is (bringing in as much air as it is expelling hence balanced). The pressurization or depressurization of a home has nothing to do with a properly balanced HRV.

 

[bholler]

That is what some don’t understand the HRV system its self is (bringing in as much air as it is expelling hence balanced). The pressurization or depressurization of a home has nothing to do with a properly balanced HRV.

Ok so how do you balance the home? And why do some hrvs have adjustments to that balance if you aren't supposed to use them

 

[Winterpeger]

A HRV system is designed to bring in fresh air and to expel the same amount of stale air nothing more nothing less, to a well sealed home. It was never designed to change the pressurization of the home … period.

 

[bholler]

A HRV system is designed to bring in fresh air and to expel the same amount of stale air nothing more nothing less, to a well sealed home. It was never designed to change the pressurization of the home … period.

Ok so how should we be addressing an imbalance in the system? I am not trying to argue. I have heard this argument before and havnt gotten an answer as to how to fix the issue

 

[Winterpeger]

Ok so how should we be addressing an imbalance in the system? I am not trying to argue. I have heard this argument before and havnt gotten an answer as to how to fix the issue

With the HRV taken out of the equation how would you normally rectify the situation, air sealing, an oak? As has been said many times on hear basement installs can be problematic with drafting issues. I have said my piece about HRV balancing, take from it what you want. Thanks for your input.
Don

 

[bholler]

With the HRV taken out of the equation how would you normally rectify the situation, air sealing, an oak? As has been said many times on hear basement installs can be problematic with drafting issues. I have said my piece about HRV balancing, take from it what you want. Thanks for your input.
Don

Yes of course air sealing on upper levels can help is that's the issue. But in most newer homes it isn't. And sometimes an oak isn't an option. So why can't an hrv be used to balance the pressure in the home considering there are mechanisms designed into some units to do that? There are hundreds of statements and articles like this some from manufacturers of the equipment available

 

[Winterpeger]

This is all fine if the stove uses a constant amount of air during combustion which I believe it doesn’t. When the stove is not being used what happens to the pressurized air, it travels to the outside envelope. I a cold climate it could cause moisture buildup in the walls and the possibility of rot and mold buildup not a good situation to be in. Since I don’t install wood stoves, just run them (much better now thanks to this site and contributors) all I could suggest is a fresh air outlet in the basement away well away from the stove with a gate on it to be used when the problem arises.

Don

 

[bholler]

This is all fine if the stove uses a constant amount of air during combustion which I believe it doesn’t. When the stove is not being used what happens to the pressurized air, it travels to the outside envelope. I a cold climate it could cause moisture buildup in the walls and the possibility of rot and mold buildup not a good situation to be in. Since I don’t install wood stoves, just run them (much better now thanks to this site and contributors) all I could suggest is a fresh air outlet in the basement away well away from the stove with a gate on it to be used when the problem arises.

Don

We are talking about tiny amounts of air here for a woodstove in relation to other things in the home. We are just talking about balancing the house. If you do that the stove will work fine and it won't cause any issues.

 

[begreen]

We are talking about tiny amounts of air here for a woodstove in relation to other things in the home. We are just talking about balancing the house. If you do that the stove will work fine and it won't cause any issues.

The amount of air the stove needs for combustion is relatively small. There are other several other factors that will create a negative pressure zone. The instructions for an HRV provide explicit instructions on how to balance for a negative pressure zone. With a balanced system, there should be no backdraft unless there are other design issues like in the OP's case.

ERV/HRV Ventilator Setup, Balancing, and Micro-balancing

A how-to guide to setting up, balancing, or micro-balancing a ERV/HRV ventilator. An essential process to achieve a balanced ventilation system.

lukeskaff.com

 

[Winterpeger]

“The instructions for an HRV provide explicit instructions on how to balance for a negative pressure zone.” Luke Skaff provides “explicit” instructions on how to balance for a negative pressure zone. I cant find any HRV manufacture advising to place a HRV into an unbalance state. Do what you think acceptable.
Don

 

[bholler]

“The instructions for an HRV provide explicit instructions on how to balance for a negative pressure zone.” Luke Skaff provides “explicit” instructions on how to balance for a negative pressure zone. I cant find any HRV manufacture advising to place a HRV into an unbalance state. Do what you think acceptable.
Don

Just balance the house and the stove will work. That's what I have been saying the whole time. Previously you said an hrv was only meant to exchange equal amounts of air. But clearly they can be used to balance pressure.

But regardless of this whole sidetrack I have a feeling the issue in this case is probably just a cold chimney.

 

[stoveliker]

I think there is a potential miscommunication here: what is being meant by "balancing".
Either balancing the *pressure* inside and outside (which is what begreen's link section 2 and 5.5 discusses) or to balance the *air flows* (i.e. flow in = flow out, link section 5.4), which would not be balancing the pressure.

Balancing flow alone between intake and exhaust alone is not enough, in general and particularly when other appliances are using air flows.
The window exercise they describe is prescisely meant to make fan-flow in unequal to fan-flow out *in order to equilibrate the pressure of the home* due to air flows not going thru the hrv (i.e. leaks).

 

[begreen]

“The instructions for an HRV provide explicit instructions on how to balance for a negative pressure zone.” Luke Skaff provides “explicit” instructions on how to balance for a negative pressure zone. I cant find any HRV manufacture advising to place a HRV into an unbalance state. Do what you think acceptable.
Don

The room location is already in an unbalanced state if this is a negative pressure zone. The HRV can balance this to near neutral.

Also, the state is not static. It varies all the time as exhaust fans are turned on, other heating or hw heaters kick in. Or when a door or window is opened. The HRV is setup to the basic state with nothing running.

But regardless of this whole sidetrack I have a feeling the issue in this case is probably just a cold chimney.

That is very possible and why I think it would be better for the OP to address one issue at a time so that a lot of tail chasing doesn't follow due to multiple variables changing at the same time.

I think there is a potential miscommunication here: what is being meant by "balancing".

Well said.

 

[Winterpeger]

I have absolutely no misunderstanding. Having a HRV in balance is one thing, having the home internal pressure balanced with the outside is something completely different. When using a HRV unit to artificially raise the basement pressure to eliminate smoke rollout, which this discussion is all about could lead to other problems down the road. Do what you believe is proper, this will be my final comment.

Don

 

[bholler]

I have absolutely no misunderstanding. Having a HRV in balance is one thing, having the home internal pressure balanced with the outside is something completely different. When using a HRV unit to artificially raise the basement pressure to eliminate smoke rollout, which this discussion is all about could lead to other problems down the road. Do what you believe is proper, this will be my final comment.

Don

So the manufacturers saying their products can be used to eliminate negative pressures in a home in their ul approved instructions are wrong?

 

[Casadecorgz]

The room location is already in an unbalanced state if this is a negative pressure zone. The HRV can balance this to near neutral.

Also, the state is not static. It varies all the time as exhaust fans are turned on, other heating or hw heaters kick in. Or when a door or window is opened. The HRV is setup to the basic state with nothing running.


That is very possible and why I think it would be better for the OP to address one issue at a time so that a lot of tail chasing doesn't follow due to multiple variables changing at the same time.


Well said.

Hey! Just wanted to let you know that I talked to my chimney company and they put me on the calendar two weeks from now. They’re going to remove the liner, attach an extension to the tee, and cap it. They confirmed the whole liner is insulated. Thank you so much for your advice! It potentially saved me so much headache.

I have the ERV install coming up and I’m also swapping out my stove for a Regency F1500

 

[begreen]

Hey! Just wanted to let you know that I talked to my chimney company and they put me on the calendar two weeks from now. They’re going to remove the liner, attach an extension to the tee, and cap it. They confirmed the whole liner is insulated. Thank you so much for your advice! It potentially saved me so much headache.

I have the ERV install coming up and I’m also swapping out my stove for a Regency F1500

Good, that should help the cold draft. The F1500 is a bit on the small side. It'll be fine for chill chasing, but not for 24/7 heating. The F2450 would be a better fit.