Circulating heat in a house with an unusual layout...

[Ashful]

I don't think either were attic fires. In fact, one started with a toaster, but once things got going enough to warm up a nearby thermostat, the attic fan kicked on and finished the job. The firefighters didn't stand a chance at saving the structure, once that happened, which I think was the point of the report.

 

[daleeper]

OP's question of circulating heat comes up often, but he has a tough situation to deal with. Usually it is us with stoves in the basement that have trouble getting hot air to go upstairs the way we think it should. There is no easy way to get that hot air to go down, and if the stove were located in the bottom floor, there is no guarantee that it would heat the upstairs the way you would want it to either, but it is a shame that fireplace wasn't put downstairs.

I would be playing with fans and the return duct to see what might work, but I have little faith that you're going to get useable heat down to the bottom where you really need it. That concrete berm wall and floor is going to be hard to warm up with wood heat from the top floor. Use some smoke (incense, cigarettes, something that generates a little smoke) to test how the air wants to naturally flow through the house, and then use fans to assist air movement. As someone already pointed out, small fires upstairs, add/move stove downstairs would be most likely solution.

Good luck.

 

[MDFisherman]

Regarding closing off the large cold air return on the lower level and only using the small return up near the stove: These cold air return vents are calculated for optimal performance. It's probably okay to temporarily seal off the large return to run a short test to see if you can move any heat that way, but I wouldn't advise using this as a permanent fix. If it does seem to work, then you would need to set up (or enlarge the small return) another return equal to the size of the large one that you eliminated or you risk damaging your central system's fan. When I tried to move heat from my basement stove through my house's duct work using my central system's fan I had very poor results.

Blocking off returns is never a good idea unless you are adding additional return ductwork/grilles, free area etc. Forcing air through ductwork at higher velocities just leads to more leaks in your ductwork and overworking the fan as stated.

I don't think adding a separate fan with ductwork would do anymore than adding a large in the room. I would have to agree that if you want heat on lower levels your best option would be to add another stove.