It's basically because they don't directly convert electricity into heat, they just pull it in from outside. It still takes energy to 'push the heat uphill' from a cold place to a hot place, but less than directly heating.
To take my previous comment to the next level, have you ever put your finger over the end of an old-school bicycle pump and tried to push it in? If you have, you'll know that the pump gets hot. The reason is that you are not only compressing air, you are compressing the heat that the air has. This raises the temperature and we can use this phenomenon to move heat around.
Imagine you were outside where it was cool and you extended the bicycle pump and blocked the end permanently.
Then you went inside hour house and compressed the pump. The air (and heat) in the pump would be compressed into a smaller space, so it the air temperature of the air in the pump would increase. If you compressed it a bit, the air in the pump might go up to be the same temperature as the air inside your house. If you compressed it even more, it would get hotter than the air inside the house. If you then held it there, over time, the heat inside the pump would transfer through the wall of the pump to the air in your house. This would cause the air inside your house to warm up and the air inside the pump to cool down until they are the same temperature. In doing this you have taken the heat in the air outside, and released it inside.
If you then went back outside and allowed the pump to extend again, then the air would decompress and, because the heat previously left the air in the pump (when it was inside), it would get quite cold. Colder than the air outside. If you then waited again, the air in the pump would gradually warm up, drawing heat from the air from outside of your house. This happens because even though the air outside is cool, it's still warmer than the air in the pump.
Rinse and repeat. An air conditioner on heating mode, or a heat pump basically work in the same way. However, rather than using a bicycle pump, they have fluid running in a loop from inside to outside and back inside. The evaporator (outside the house) collects heat by allowing the fluid to 'expand' and cool below the ambient temperature outside. The condensor (inside the house) releases the heat by allowing the fluid to 'contract' and heat above the ambient temperature inside.
In this way, no heat is directly created from electricity. It is just moved from outside to inside. Believe it or not, this takes less energy than converting electricity into heat directly.
I've deliberately not talked about phase change here to keep it simple, that doesn't change the basic idea behind it.
Wow, that's amazing. Thanks for such a great explanation!!
I'd never thought of the cooling pipe used in CPUs before, but it's really no different
This would be a great post for an “explain it like I run Reddit” instance.
!nostupidquestions is a community dedicated to being helpful and answering each others' questions on various topics.
The rules for posting and commenting, besides the rules defined here for lemmy.world, are as follows:
Rule 1- All posts must be legitimate questions. All post titles must include a question.
All posts must be legitimate questions, and all post titles must include a question. Questions that are joke or trolling questions, memes, song lyrics as title, etc. are not allowed here. See Rule 6 for all exceptions.
Rule 2- Your question subject cannot be illegal or NSFW material.
Your question subject cannot be illegal or NSFW material. You will be warned first, banned second.
Rule 3- Do not seek mental, medical and professional help here.
Do not seek mental, medical and professional help here. Breaking this rule will not get you or your post removed, but it will put you at risk, and possibly in danger.
Rule 4- No self promotion or upvote-farming of any kind.
That's it.
Rule 5- No baiting or sealioning or promoting an agenda.
Questions which, instead of being of an innocuous nature, are specifically intended (based on reports and in the opinion of our crack moderation team) to bait users into ideological wars on charged political topics will be removed and the authors warned - or banned - depending on severity.
Rule 6- Regarding META posts and joke questions.
Provided it is about the community itself, you may post non-question posts using the [META] tag on your post title.
On fridays, you are allowed to post meme and troll questions, on the condition that it's in text format only, and conforms with our other rules. These posts MUST include the [NSQ Friday] tag in their title.
If you post a serious question on friday and are looking only for legitimate answers, then please include the [Serious] tag on your post. Irrelevant replies will then be removed by moderators.
Rule 7- You can't intentionally annoy, mock, or harass other members.
If you intentionally annoy, mock, harass, or discriminate against any individual member, you will be removed.
Likewise, if you are a member, sympathiser or a resemblant of a movement that is known to largely hate, mock, discriminate against, and/or want to take lives of a group of people, and you were provably vocal about your hate, then you will be banned on sight.
Rule 8- All comments should try to stay relevant to their parent content.
Rule 9- Reposts from other platforms are not allowed.
Let everyone have their own content.
Rule 10- Majority of bots aren't allowed to participate here.
Our breathtaking icon was bestowed upon us by @Cevilia!
The greatest banner of all time: by @TheOneWithTheHair!