moving heat in a ranch <revisited>

Ceiling fans to stir it up if you are already pushing the cold air towards the stove.

Shawn

In our old house, the ceiling fan did a lot to push hot air off the ceiling through the doorway. If you stood outside the door (in the next room), you could really feel warm air being blown.

I tried running the HVAC fan, which moves a lot of CFM, and it worked OK at cooling down the room with the stove, but didn't really warm up the rest of the house. I suspect I lost too much heat to the ductwork in the crawlspace.

Later, I cut a hole in the return and put a 150 CFM fan into the hole, in an attempt to draw warm air directly into a cold room. It kind of worked. The air coming out of the fan was warmish (same temp as stove room, say maybe 80F.) but the quantity of air wasn't enough to really make a difference. Maybe 2F in the target room at bedtime.

So I'd say that running 4" flex duct through your attic is a total waste of time. If you could run like a 12" duct with an HVAC blower, then maybe, but only if you could run it in conditioned space -- I'm certain my crawlspace is warmer than your attic...

Now looking at your floorplan -- if you could make a large duct that went out through the garage (over the entry door) and into that other room, and put a big fan in it, then you'd move air in a circle through the primary living spaces.

My opinion would be that it doesn't look like you've optimized your cold air feed, and I'd give that a try. A header fan only on the doorway to the stove room (if I'm reading this correctly) is not the best you can do. For one, get a fan down on floor level, pulling air out of those back rooms. If it were me, I'd put a table fan on the floor at the junction between the living room/kitchen/hallway and see what that would do for you. I essentially heat a back bedroom from two rooms away with an 8" fan on the floor in the bedroom doorway....and it is not a straight shot. The difference is pretty dramatic. It doesn't really take much to get that loop circulating.

Your idea for the attic routing can work well, but you have to be very careful to use high R rated ducting...and seal it. Btw, duct tape is good for almost anything other than that task for which it is named. I'd check out the Fantech in-line fans. Excellent product. For room to room transfer fans it is hard to beat the Tjernlund Airshare. I have been involved in a number of projects using several hundred of them on housing authority work. Not wood applications, but the Airshares were excellent.