I live in a pretty old house in the midwest, built 1929, bought in '21, single-story, ~1300ish sqft, and with a large, spacious basement. Every time summer comes around I’ve had issues with the basement getting MUCH colder than the rest of the house (like >10 degrees F difference), presumably due to poorly-insulated floors and cold air sinking. The HVAC is still capable of keeping the main floor at the temp set on the thermostat, but the temperature differential indicates it’s working quite a bit harder than it really needs to be, and is probably wasting quite a bit of money.
I’m planning on getting an insulation specialist in at some point to go over options for shoring up the insulation, but I’m wondering if there’s anything else I could do to recirculate air in the basement through the rest of the house - even with good insulation, I feel like the laws of thermodynamics would still result in a basement at least fairly colder than the rest of the house.
Is there anything I could look into that is reasonably cost-effective for circulating air from the basement to the rest of the house so my HVAC doesn’t have to work so hard in the summer? Thanks
I initially had the opposite problem where my uninsulated cinder block basement was too hot in the summer and too cold in the winter and my basement didn’t have any HVAC registers or returns. The only air conditioning it got was from a window AC unit and leakage from the HVAC ducts. Over several years I ended up adding 2" foam insulation internally to all the exterior walls, insulating the ceiling to the basement (mostly for sound absorption but it also helped with floor temperatures), and adding returns and registers in the basement. I also added an inline booster fan to help pull air up to a second floor bonus room that was an addition. Now the basement is always comfortable, the second floor is much more comfortable, and the energy costs are about the same. My moisture levels are 30-50% in the summer.
If you pull air from the basement, it’s going to get replaced with warmer, wetter air from upstairs. As it cools the air is going to deposit that water on the coolest surfaces. You might be trading this problem for another, more damaging one.
Wouldn’t the AC still be dehumidifying the air circulation on the upper floors?
Yeah, the basement is going to be colder…
You can circulate the air if you want to balance it out, but the basement is going to get colder again.
If you’re talking about saving energy:
At about 3pm circulate the air. That’s a little before your AC is going to start experiencing it’s highest workload.
At around 6pm or when ever, stop.
Try it for a couple of days with just a fan. If it’s a noticeable difference and you like it, you can get a vent installed that pushes up from the basement, and another somewhere else that just goes straight to the basement. You can put the fan/blower on a timer. I’d recommend one of those “smart plug” things, they work as a timer and you can also controll locally from your phone.
But if you’re circulating air 24/7, it’s just making your AC cool even more air.
So you just want to use it to dump a bunch of cold air when you need it most, and then let it naturally cool down the rest of the nigh/day.
Whether or not this adds up to more than negligible benefits for energy use…
I have zero idea.
But it’s essentially just an inefficient heat pump. The theory behind it is sound.
