Wood burning insert in NC, is it worth it?

[Tron]

You both must have plenty of make up air to not have any influence. Good job.

Not really, I mean, the house isn't 100% airtight, but not a drafty shed, either.
My point was that the air going into the return at floor level isn't that warm in the first place, and would lose most of it's heat going through the ducting in the attic.

I don't have an OAK (stove is not on an outside wall and the foundation is concrete), but I certainly notice pressure changes in the house, especially on low-draft days. Such as when the bathroom vent is running. To run the kitchen vent, which is industrial-sized, I certainly have to open a window not to get backdraft into the stove.

 

[stoveliker]

My view is that if one uses an HVAC ducted fan system, the ducts should be in the insulated envelope as mentioned above, AND it works best if there is no return in the stove room, just a register *blowing* air. The return(s) should be as far away as possible from the stove room. That air pushed into the stove room through the register will push warm air out of the stove room.

That way, if there are pressure differences, at least the stove room would have a higher pressure, and the warmest air does not go through ducts (where it can cool down), but through the living space where it is beneficial.

 

[Tron]

AND it works best if there is no return in the stove room, just a register *blowing* air. The return(s) should be as far away as possible from the stove room.

Ideally, agreed. My layout is that the return is in a hallway connecting the stove room and the bedroom. So no good way to get warm air into the bedroom, sadly.

 

[LakeFall]

You both must have plenty of make up air to not have any influence. Good job.

BKVP

Or we just have crappily-sealed houses
Assuming no air loss in the HVAC, wouldn't the only effect be a pressure drop from flowing air? The same amount of make-up air still needs to enter the house to get the insert drafting (upwards), right?

 

[Tron]

Assuming no air loss in the HVAC

As a rule of thumb, I've heard that a loss of 20% through the ducts (seams and such) is considered normal. Which then obviously has to be made up from cracks around the house. Plus the amount the stove uses.

 

[snojetter]

You both must have plenty of make up air to not have any influence. Good job.

BKVP

Or maybe lucky. When the house was built, I put a return near the stove with the intention of pulling warm air into the ducts and redistribute it. I think a lot of people have this idea, but it doesn't seem to work in practice - certainly not the slam dunk it sounds like in theory. The house is well sealed with closed cell foam insulation, but includes a "passive air ventilation" system which is basically two holes in the wall in our mechanical room. I'm also running a a 25-ish foot flue/chimney with no damper. All in all, the stove (and house, I suppose) breaths well under all conditions and I have full control for roughly 12-hour loads throughout the burning season. If I lucked my way into the right combination of home features to make for an easy burning Princess, I'm ok with that 😁

 

[stoveliker]

I hope the return is farther than 10 ft from the stove - per US code.

 

[begreen]

Or we just have crappily-sealed houses
Assuming no air loss in the HVAC, wouldn't the only effect be a pressure drop from flowing air? The same amount of make-up air still needs to enter the house to get the insert drafting (upwards), right?

If an hvac system is balanced in an open home, then running it shouldn't influence the fire. It's when the return is in a wing, a room that gets closed off by doors, or side apt., that things can get imbalanced. Or the system is poorly designed. Our forced air heat pump has no influence on the fire in our open floorplan home.