pre winter wood stove circulation question

[robson]

i have a 2 story house with a wood stove insert in the livingroom / diningroom. the stove has a blower. the room is approx 15x40'. it gets very hot in that room and i'm trying to get the warm air to the second floor. i can't cut vents in the ceiling as the 4 bedrooms are directly above the main area and it would be too hot. how do i circulate the heat? i have tried the 2 fans in the doorways of the room to attempt to get the air up the stairwell to no avail. any suggestions? burning the stove at a lower temp does not solve the problem. i need to get the warm air up and the cool air down.

ty

[barry]

You don't tell us the location of the fans.

In a situation similar to yours, sometimes I send some of the woodstove output up one floor. Natural convection sets up prettty good counter-currents. Using small fan(s) to boost these currents gets many times the cfm moving.

IOW, high up, fan discharging heated air away from stove; low down, opposite direction.

You may want to place small fans in more locations. You may want to escalate to serious air-movers.

This sort of approach works just fine for me, down to single-digits F outside.

HTH, J

[nicksanspam]

How about vents with dampers?

Nick

[Colbyt]

If you have a forced air furnace that serves both floors just leave the fan in the on position. Adding a return air register high on the wall in the room with the stove will help move a little more warm air through the system.

Hope this helps.

Colbyt

[Edwin Pawlowski]

Facts: You will never get the even temperature of a typical house heating system The cold air is coming down and the hot air is going up. Just not the volumes you want.

You must move air out as well as more air in to any of the rooms. You can often help by mounting a small fan in the doorway at the top to blow the hot air in. This forces the cold air out. It also allows you to hit your head at times. It was common to put floor vents above the stove and also at the other end of the house. Ideally it was in a hallway. I'm told this is not allowed by fire codes though.

You need a series of small fans or ducts to get the distribution that you need. It will take some experimenting, but you can improve, but never get full even distribution from a wood stove.

[nicksanspam]

If the bedrooms are too cold now and "cutting vents" would make them too warm, cutting smaller vents (or installing vents with dampers) would make them "just right," no?

People like cooler bedrooms. How about 5 F less than the living room?

It isn't hard to estimate the vent sizes needed to keep the bedrooms

65 F with a 70 F living room. Estimate the heat loss from the bedrooms to the outdoors at 65 F... 880 ft^2 of R20 walls and 600 ft^2 of R40 ceiling would lose (65-30)(880/20+600/40) = 2065 Btu/h on a 30 F day. And 2065 = 16.6Avsqrt(8')5^1.5 makes total vent area Av = 3.9 ft^2.

We always have choices.

Nick

[nicksanspam]

This answers the question, and the dazzling arithmetic is 300 years old :-)

Put the vents in the ceiling. Forget the air handler.

And lose the sarcasm, s'il te plait.

Nick

[Edwin Pawlowski]

Once again Nick dazzles us with his math formula but fails to answer the question.

Just where and how do you run these vents and the appropriate air handler?

[nicksanspam]

1. Buy some 12"x4" floor registers with dampers from Home Depot, about for 2 brass-plasted versions for low-traffic areas or for each for solid brass in high-traffic. OR, buy some 13.5"x13.5" Hart and Cooley registers. Both types fit nicely between joists on 16" centers.
2. Put a supply vent in each room, away from outside walls, ideally near the ceiling, eg a screen above each bedroom door off a central stairwell, and install return vents near outside walls by drilling a hole in the ceiling (taking care to avoid wires and pipes and joists), then cutting an outline for the register from the floor above with a Sawzall or a sabre saw with a long blade. Install grates with drywall screws into studs from above and below.

I did this in a basement ceiling to help warm air move up into a house. The lower grates weren't required for cosmetics.

Nick

[Edwin Pawlowski]

Sure, but you use it so well.

Easier said than done. That is one reason the OP asked the question of HOW?

And Nick is bi-lingual also.