this post was submitted on 21 Sep 2026
12 points (87.5% liked)

Gardening

6914 readers
132 users here now

Your Ultimate Gardening Guide.

Rules

  1. Be respectful and inclusive.
  2. No harassment, hate speech, or trolling.
  3. Engage in constructive discussions.
  4. Share relevant content.
  5. Follow guidelines and moderators' instructions.
  6. Use appropriate language and tone.
  7. Report violations.
  8. Foster a continuous learning environment.

founded 3 years ago
MODERATORS
scarabic@lemmy.world
sabbah@lemmy.world
ManamaKhan@lemmy.world
Spacebar@lemmy.world
Bitswap@lemmy.world
12
Why does no one seem to use peltier elements to heat small greenhouses? (feddit.org)
submitted 2 weeks ago* (last edited 2 weeks ago) by viertesauge@feddit.org to c/gardening@lemmy.world
24 comments fedilink hide all child comments
 

Genuine question. When I look up options for heating greenhouses its either propane, kerosene or electricity. So if you dont want to use fossil energy for any reason, why not use peltier elements which would boil down to resistive heating and moving heat from the outside to the inside?

Is it because they dont last in the weather? Or because they require a DC source? (couldnt you simply move the PSU inside the greenhouse and use any conversion losses as additional heating?) Or maybe its because you would have to possibly cut a hole in your greenhouse walls so that the peltiers cold side is actually on the outside?

you are viewing a single comment's thread
view the rest of the comments
[–] dgdft@lemmy.world 7 points 2 weeks ago (1 children)

That understanding is mostly correct, but when you crunch the numbers, the “ + whatever heat it moves from one side to the other”-component of the equation tends to be small in practice relative to the input energy, such that you wind up very close to resistive heating. At best, you’ll get a COP around 1.5.

That means you pay a lot of overhead for marginal efficiency gains, and if you have clean electricity to run your heat pump, you already have clean electricity to run resistive heat.

[–] viertesauge@feddit.org 2 points 2 weeks ago

yeah marginal gains are probably the actual reason