Yes, thermal mass only serves to even out fluctuations in temperature. If the outside environment swings between hot and cold then a building with high thermal mass will tend to have a temperature in the middle of those two extremes. Like how a heavier ship is tossed about on the waves much less than a small boat.
But if a place is consistently hot or cold for a long time thermal mass doesn’t really do anything. At most you can use it as a battery, so you can, for example, run a heat pump while electricity is the cheapest and use the thermal mass to maintain the temperature you established over the costly period.
So many people think that its a substitute for insulation though, which slows down the rate of heat transfer in or out, and does actually let you use less energy to maintain a given temperature.
Korhaka@sopuli.xyz 9 hours ago
A large part of the problem is people trying to get as much sun in the house as possible. If you don’t do that its still perfectly comfortable without AC. Just open the windows overnight and shut them in the morning.
Would like to get a reflective film for the windows to reduce the sun coming through though rather than just shutting the curtains as that still lets some heat in but its better than open curtains.
cynar@lemmy.world 8 hours ago
You can get wall insulation that is, effectively a stiff bubble wrap made of milar foil. It’s not even that expensive I cut it to match windows, then used suction cuts to fix it in place.
It’s amazingly effective at keeping heat out. During the 45 degree weather, I barely had to use my air conditioner, to have a comfortable temperature.
Korhaka@sopuli.xyz 5 hours ago
The film allows you to still see out and get a bit of light and doesn’t result in your house looking like a drug den. I am aware of the foil though. How does it compare to tinfoil on cardboard?
cynar@lemmy.world 5 hours ago
I’ve not tried tin foil. The insulation seems to be more robust, and it wants to lie flat. It’s also optimised for IR reflection, tin foil isn’t.
Downside, it’s a near perfect blackout material. I only put them up when it’s going to be ridiculously hot, and only on the sun facing side of the house.