So my home office is in our basement while my wife’s is in a finished attic space. We have a mini split system, but it has to be all heat or all cooling, and many days it’s cold in my office, but hot in my wife’s office.
Thanks to a defunct chimney, I have a pretty decent path from the attic to the basement that could easily accommodate some kind of ducting.
I’d like to make a system that can push air from my office to hers or vice versa as needed. I think this would really help the house in general as cold air tends to pool in the basement.
I’ve seen plenty of ducting booster fans, but I’d like something with a speed (or at least direction) control accessible from the outside.
Does something like this exist? It would need to force air through maybe 30-40’ of ducting.
I have an inline duct booster fan with a control. I would recommend just putting one in your existing HVAC duct that runs upstairs. Also, if you don't already, use your HVAC fan on "On" rather than "Auto" whenever there is an unwanted temperature differential. Overall I don't think your idea about repurposing the chimney with additional duct work to move air is a bad idea. Especially given your description that multiple renovations have been done and perhaps a holistic approach to the HVAC system wasn't taken. Our HVAC contractor re-routed our gas furnace's exhaust gasses that had been going from the basement all the way through all the floors to the attack, the newer model just goes out the wall in the basement. The old exhaust was used to add a return from the upper floor to the basement. And of course, always check that you have more than enough insulation.
I have a mini-split. There’s no ducting in the walls.