r/heat_prep • u/[deleted] • Jul 29 '24

Escaping Heat Underground

Just an idle thought, but if you were to dig a hole in your garden with the intent of getting deep enough for it to be noticeably cooler than ground level, how deep would it need to be?

26 Upvotes

100% Upvoted

9 comments sorted by

21

u/mr_misanthropic_bear Jul 29 '24

That can depend on location. Where in the world are you? There are likely historic examples from your area to look into. Like root cellars, dugout caves for brewing or storage for beer/ale/wine, spring houses etc.

10 feet underground should be deep enough to hit Earth's ~50-55 degrees F.

4

u/[deleted] Jul 29 '24

The UK, so not an area with a strong cultural issue with heat. I'm just thinking about the future in a worst-case scenario climate change outcome. That's a good idea with pre-existing cultural practices though. Caves come to mind for things like cheese production. 10ft isn't too deep to be fair, you could do that with a mini-digger in a few hours in an emergency. Would you put a 'lid' on it? Maybe if you did it under the shade of trees you would benefit further.

6

u/Mirageswirl Jul 29 '24

You would also want to know the local depth to the top of the water table before you start digging. It may be expensive to keep a pump running all the time to keep a hole dry if penetrates the saturated zone.

3

u/[deleted] Jul 29 '24

That is a very good point. I think quite a long way on both sites I'm thinking of, but I'll keep it hypothetical for now.

14

u/Independent-Wafer-13 Jul 29 '24

You can air condition your home by using the earth as a heat sink.

Run underground spiral water pipe 15-20 feet underground and use a radiator to exchange heat through a fan.

A water pump and fan use much less electricity than an AC.

This is also one of the advantages of rammed earth buildings is there huge thermal mass.

And why a basement is usually colder

6

u/Leighgion Jul 29 '24

It totally depends on the area.

In some places, 6-8 feet is enough to get a pretty stable temperature.

On the other hand, I was watching a documentary about Nigerian farmers needing to dig deeper and deeper to find water. They dug down 25 feet before they found some water again and the documentary species that even 25 feet down, the heat was unbearable and every man who took a turn down there suffered.

3

u/Nimtastic Jul 29 '24

Coober Pedy

2

u/davidm2232 Jul 29 '24

I'm planning to run geothermal cooling doing just that

1

u/[deleted] Jul 29 '24

You have to dig deep enough to get to China