Transferring Wood Stove Heat
Hello,
Apologies if this has been asked and answered and I can’t find it.
What are good-better-best options for heat transfer from an over heating wood stove living room?
We are in a 1960’s ranch home (New England, zone 5) with finished walk out basement, primarily living on the upper level, recently with blown in ~R50-60 cellulose in the attic space. Propane hydronic baseboard heating.
There is a Vermont Castings Montpelier ~50k BTU wood insert in the living room that is isolated from the rest of the home by a single door; this room of course gets quite hot.
My initial thought is to have an in -line ventilation fan run through the unconditioned attic space from the kitchen/mudroom area (cathedral ceiling) and vent through the ceiling near the wood stove thus drawing warm air through the door to the remainder of the house.
Transom would be another option perhaps.
Box fan in the doorway doesn’t seem to work.
Thanks for the considerations.
-M
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Replies
What's the goal here? Are you trying to heat the house with wood or are you trying to make an overheated room more comfortable?
Good clarification;
Primary goal is make the overheated room more comfortable; but supplementing whole house heat is a close second.
Gotcha! You're in a pickle common to wood - usually the output is much too big for the room and distribution is poor. There are options to fix this, but they're not cheap. Here's an example of using a wood fired boiler to heat an efficient house. Basically, it involves lots of water storage - since you have baseboard, it could work for your situation.
https://www.greenbuildingadvisor.com/article/flatrock-passive-firing-up-the-heating-system
The formula for heat transfer by air movement is 1.08*(airflow in CFM)*(temperature difference in F)= BTU/hr. So let's say you wanted to move 30,000 BTU/hr and keep the rest of the house within 10F, you'd have to move 3,000 CFM. So no, a box fan isn't going to cut it. You'd need about a 4'x4' duct with the air moving at 20 mph to get that kind of flow.
There's reason HVAC systems have big ducts and big fans.
You might try wood stove forums. What I’ve read is that you lose a lot of heat trying to move warm air. A better strategy is to try to move cold air to the stove to set up convection currents