2 ms·
> "...they generate more heating/cooling than electricity used." that's thermodynamically impossible. @dktoao, being a mechanical engineer, surely understands
by clairity 4y ago
> "...they generate more heating/cooling than electricity used."
that's thermodynamically impossible. @dktoao, being a mechanical engineer, surely understands this, and made a statement that is different, and more plausible.
COP is a ratio of change in energy (e.g., temperature) produced against a common benchmark (running electricity through a resistive element, for example). that's how it can be greater than 100%. absolute efficiency (what @dktoao offered) compares against a 100% conversion of energy from one form (or place) to another. in this case, you cannot beat 100% (or generally get super close) due to the 2nd law of thermo.
- coryrc 4y agoBasically no common A/C is 30% efficient in any sense of the word. There's a scenario where you can argue it can get as low as 50%, but no common A/C I have ever heard of is using moving less than 2x heat power as electricity power used. 30% is wrong no matter how you cut it. And, "efficiency" doesn't matter. COP does. COP is what is reflected on your electrical bills.
- clairity 4y agoit's basic thermodynamics. you mixed the two, as i explained previously, and now you're leaning into the misconception, rather than acknowledging the difference.
- coryrc 4y agoIn no way is anything you said in either post of use to anyone. If I am in my house, use 1000 W of electricity, get 3000 W of heating, that is what is important. No shit the extra heat comes from the environment. It doesn't matter unless you live within a house completely located inside an artificial climate-controlled area, which applies to... none. No houses.