5 ms·

How quickly does heat naturally increase in a house that's been cooled like that? I've only lived in apartments, but I guess it gets back to equilibrium with o

How quickly does heat naturally increase in a house that's been cooled like that? I've only lived in apartments, but I guess it gets back to equilibrium with outside temperature in a few hours once AC is turned off. I guess a couple hours of cheap cooling in the middle of the day might save an hour of expensive cooling later, if it's timed right. I'm interested if there have been any studies or maths to back it up and quantify the effectiveness.

spywaregorilla 3y ago
depends on insulation
- jacquesm 3y ago
  In part, but that's not all of it. The bigger driver is the amount of thermal mass.
coolsunglasses 3y ago
Using the house as a thermal battery (heat or cold, dealer's choice) works great in my house but my house is so well insulated that we have CO2 problems. Planning to setup a fresh air intake with an ERV to mitigate this.
BobaFloutist 3y ago
I mean that's going to depend heavily on insulation, light insulation, how many device you have generating heat (computers, servers, refrigerator, tv), and how many times you enter/leave your place. In a well insulated place with airlock-style entrance (even just a mudroom with solid insulation on both doors) where you're blocking out sunlight and not running a ton of electronics, it could easily take hours and hours.
xnx 3y ago
Some research here: https://www.pv-magazine.com/2023/08/14/mitigating-residential-duck-curve-via-solar-pre-cooling/ https://www.pv-magazine.com/2023/08/14/mitigating-residentia...
wolverine876 3y ago
> I guess it gets back to equilibrium with outside temperature in a few hours once AC is turned off. I've been in houses where we shut the windows as soon as possible after sunrise, as temperatures started increasing, and the house never caught up with the outside temperature - it was cooler all afternoon, cooler until sundown. No AC needed. I think that tactic might work well generally. Just let in the cool air at night, shut the windows and trap it. At least you can save a good part of the day's AC. It's obvious, free, and simple, but I never see it discussed.
- iopq 3y ago
  My dad has holes under the window for the water to roll off when you clean it. Those holes let in cold and hot air readily. He doesn't even wash the windows. It's a really bad design for what you're saying
petre 3y ago
Read on about decrement delay and thermal buffering if you're curious. https://www.greenspec.co.uk/building-design/decrement-delay/ https://www.greenspec.co.uk/building-design/decrement-delay/

spywaregorilla 3y ago

depends on insulation

jacquesm 3y ago
In part, but that's not all of it. The bigger driver is the amount of thermal mass.

coolsunglasses 3y ago

Using the house as a thermal battery (heat or cold, dealer's choice) works great in my house but my house is so well insulated that we have CO2 problems. Planning to setup a fresh air intake with an ERV to mitigate this.

BobaFloutist 3y ago

I mean that's going to depend heavily on insulation, light insulation, how many device you have generating heat (computers, servers, refrigerator, tv), and how many times you enter/leave your place. In a well insulated place with airlock-style entrance (even just a mudroom with solid insulation on both doors) where you're blocking out sunlight and not running a ton of electronics, it could easily take hours and hours.

xnx 3y ago

Some research here: https://www.pv-magazine.com/2023/08/14/mitigating-residential-duck-curve-via-solar-pre-cooling/ https://www.pv-magazine.com/2023/08/14/mitigating-residentia...

wolverine876 3y ago

> I guess it gets back to equilibrium with outside temperature in a few hours once AC is turned off. I've been in houses where we shut the windows as soon as possible after sunrise, as temperatures started increasing, and the house never caught up with the outside temperature - it was cooler all afternoon, cooler until sundown. No AC needed. I think that tactic might work well generally. Just let in the cool air at night, shut the windows and trap it. At least you can save a good part of the day's AC. It's obvious, free, and simple, but I never see it discussed.

iopq 3y ago
My dad has holes under the window for the water to roll off when you clean it. Those holes let in cold and hot air readily. He doesn't even wash the windows. It's a really bad design for what you're saying

petre 3y ago

Read on about decrement delay and thermal buffering if you're curious. https://www.greenspec.co.uk/building-design/decrement-delay/ https://www.greenspec.co.uk/building-design/decrement-delay/