this post was submitted on 07 Jan 2025
315 points (97.3% liked)

Technology

60316 readers
3332 users here now

This is a most excellent place for technology news and articles.


Our Rules


  1. Follow the lemmy.world rules.
  2. Only tech related content.
  3. Be excellent to each another!
  4. Mod approved content bots can post up to 10 articles per day.
  5. Threads asking for personal tech support may be deleted.
  6. Politics threads may be removed.
  7. No memes allowed as posts, OK to post as comments.
  8. Only approved bots from the list below, to ask if your bot can be added please contact us.
  9. Check for duplicates before posting, duplicates may be removed

Approved Bots


founded 2 years ago
MODERATORS
you are viewing a single comment's thread
view the rest of the comments
[–] ikidd@lemmy.world 69 points 1 day ago (4 children)

Actually, I'm surprised they weren't using them long before. It's basically AC with an extra valve. Thought they get priced like they're some sort of new technology.

[–] jqubed@lemmy.world 42 points 1 day ago (1 children)

There was never really a need in ICE vehicles since they can primarily use waste heat from the engine.

[–] Ulrich@feddit.org 13 points 1 day ago (1 children)
[–] tb_@lemmy.world 11 points 1 day ago (1 children)

Pretty sure @jqubed@lemmy.world meant to explain why they weren't a thing in cars in general

[–] Ulrich@feddit.org 0 points 1 day ago

Yes that was my point.

[–] lemming741@lemmy.world 11 points 1 day ago (1 children)

Vapor injection is the new technology. It's why older heat pumps were useless below 32f.

[–] ikidd@lemmy.world 12 points 1 day ago

Vapor injection becomes an excuse to downsize the compressor and lowers the cost, it seems. You could easily go lower than 32 if you oversized the pump before EVI, but those were only in specific heatpumps.

[–] kameecoding@lemmy.world 2 points 1 day ago

I reckon they thought seat heating and steering wheel was enough, and it kinda is for the most part

[–] echodot@feddit.uk 6 points 1 day ago (2 children)

I suspect the reason for that was that the pumps used in car ACs are not really very powerful. They were alright for cooling the car down, but for heating heat up in a cold environment you need a fair amount of throughput, they work if you have the throughput, but you need it to be there.

They work by pulling ambient heat out a large part of the outside and dumping it into the small inside. You need many times the contents of the interior to warm up if it's a cold day outside. Thus you need a lot of air and if you want it to happen in a reasonable time frame you need quite a powerful little motor. The ones on houses are fine because they're huge anyway.

[–] Ulrich@feddit.org 11 points 1 day ago (2 children)

It uses the same amount of energy to create cold as it does to create heat.

[–] Bronzebeard@lemm.ee -1 points 13 hours ago

Heart pumps don't create heat, they move it.

[–] Photon@feddit.org 4 points 1 day ago (1 children)

Well it's about temperature differences, those are larger in winter I guess. On the other hand there is a lot more radiative heat load in summer...

[–] Hule@lemmy.world 0 points 19 hours ago

There's a "sweet spot" for temperatures, so if a compressor and heating agent works well in summer, it won't work well in winter.

[–] Chronographs@lemmy.zip 3 points 1 day ago

They also need to be able to get the cold side colder than the outside air so once it gets too cold they don’t really work. There can also be some problems with condensation but when they do work they’re great.