this post was submitted on 17 Sep 2025
263 points (98.5% liked)
Technology
75258 readers
3690 users here now
This is a most excellent place for technology news and articles.
Our Rules
- Follow the lemmy.world rules.
- Only tech related news or articles.
- Be excellent to each other!
- Mod approved content bots can post up to 10 articles per day.
- Threads asking for personal tech support may be deleted.
- Politics threads may be removed.
- No memes allowed as posts, OK to post as comments.
- Only approved bots from the list below, this includes using AI responses and summaries. To ask if your bot can be added please contact a mod.
- Check for duplicates before posting, duplicates may be removed
- Accounts 7 days and younger will have their posts automatically removed.
Approved Bots
founded 2 years ago
MODERATORS
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
That scales down to the home level easily. Box filled with cement dust, dirt, sand, gypsum, gravel is all free material. Water gets more heat lift from heat pumps, but can't store as much heat in a volume as dirt. Both are highly complimentary, because delivering hot water to everywhere in a home is efficient, quiet, dust free, heat. But if you are lucky enough to have centralized option, that is easier.
It takes an extremely large volume of any of these materials to store any useful amount of heat to get you through a cold night or something. The volume looks more like a room than a box, unless you can somehow make it molten that is
I did math for Toronto, Canada. 2000l of hot water was enough (2m^3^). Winters here have gotten cloudier from great lakes warming. Instead of more water as a buffer, dirt is much more space efficient, and just needs the hot water routed through it to get heat transfer.
If hydronic heating system was already being directed towards outer walls instead of straight up from water storage, then a tall "hot dirt" storage, and dual cold water mixing valves (pre and post dirt flow) next to each other, it's less in additional storage costs per heat unit than water, though it does use more electricity to input heat compared to heat pump.
No need for temperatures higher than melting/softening point of copper to get useful heat storage for a home. Just water can be enough if you have the room.
Have you never lived in an apartment building?
I don't know why we haven't come up with better solutions for piping. Or maybe it's just because this building was built very cheaply. But anyway... the pipes make quite a loud banging sound if you shut them fast enough. And a lot of whoooshing in the walls just when using hot water.
High rise apartment buildings have a challenge with pumping water up more than 3-5 floors. This can be solved with intermediate storage on floors, but for high rises, forced air is the usual solution. Heat storage still works well enough with forced air, but water is much better due to internal piping through heat source, where air volume is harder to do there, and if gaining heat from outer shell, then insulation meant to keep heat in is not as good at heat transfer. Water is most perfect heat fluid in world. Air not so much.
This doesn't apply for heat delivery. Tends to be continuous. A faucet is different.
Pegging your pardon, mister.
https://www.youtube.com/watch?v=7KtyzY2rwOg