Where is this idea flawed / how to guestimate efficiency? - Page 2

Robl · 04-06-22, 02:48 AM

I just looked up EER, SEER - as a UK person these terms have been on the edge of my consciousness for some time! We get COP and SCOP here. So:

COP (Coefficient Of Performance) is Power out / Power used. Used for heating or cooling, same units used, so is just a ratio, needs conditions (Tin, Tout stating, usually in degC). COP heating is generally COP cooling+1, if the conditions are similar - heating or cooling is often unstated, and causes confusion. For a compressor it will generally be cooling stated as this is the thermal power moved by the fluid.

SCOP (Seasonal COP) tries to use appropriate conditions for your region, and needs Tout stating. I've only seen it used for heating, but I'm in the UK:-)

EER is COP but in (Btu/h)/kW and cooling specific.

SEER is Seasonal EER.

Suprisingly I found a simple EER to SEER link in a webpage - surely this is just an empirical formula that works sometimes in some places with some heatpumps?:
EER = 1.12 * SEER - 0.02 * SEER^2
https://power-calculation.com/EER_SE...nditioning.php

jeff5may · 04-13-22, 09:26 AM

While an air compressor heater and a pressure drop "vortex" cooler could be construed as a heat pump with some creative marketing and/or play on words, the system is not really considered a "standard" heat pump. As the others have stated, the compression/decompression of atmospheric air is really not energy efficient.

The missing pieces are the closed loop and the condensible gas. Even a machine with no moving parts except the compressor (think deep freezer chest) can cool (or heat, think water heater cylinder) a lot of mass. Latent heat transfer is the key.

Usually there's no such thing as a free lunch, but in this case, the engineers figured one out. Its called an EVAP chiller or a swamp cooler. Please don't make me explain how that works.

04-06-22, 02:48 AM	#11
Robl Helper EcoRenovator Join Date: Oct 2020 Location: Cambridge, UK Posts: 31 Thanks: 3 Thanked 27 Times in 14 Posts	I just looked up EER, SEER - as a UK person these terms have been on the edge of my consciousness for some time! We get COP and SCOP here. So: COP (Coefficient Of Performance) is Power out / Power used. Used for heating or cooling, same units used, so is just a ratio, needs conditions (Tin, Tout stating, usually in degC). COP heating is generally COP cooling+1, if the conditions are similar - heating or cooling is often unstated, and causes confusion. For a compressor it will generally be cooling stated as this is the thermal power moved by the fluid. SCOP (Seasonal COP) tries to use appropriate conditions for your region, and needs Tout stating. I've only seen it used for heating, but I'm in the UK:-) EER is COP but in (Btu/h)/kW and cooling specific. SEER is Seasonal EER. Suprisingly I found a simple EER to SEER link in a webpage - surely this is just an empirical formula that works sometimes in some places with some heatpumps?: EER = 1.12 * SEER - 0.02 * SEER^2 https://power-calculation.com/EER_SE...nditioning.php

04-13-22, 09:26 AM	#12
jeff5may Supreme EcoRenovator Join Date: Jan 2010 Location: elizabethtown, ky, USA Posts: 2,431 Thanks: 431 Thanked 619 Times in 517 Posts	While an air compressor heater and a pressure drop "vortex" cooler could be construed as a heat pump with some creative marketing and/or play on words, the system is not really considered a "standard" heat pump. As the others have stated, the compression/decompression of atmospheric air is really not energy efficient. The missing pieces are the closed loop and the condensible gas. Even a machine with no moving parts except the compressor (think deep freezer chest) can cool (or heat, think water heater cylinder) a lot of mass. Latent heat transfer is the key. Usually there's no such thing as a free lunch, but in this case, the engineers figured one out. Its called an EVAP chiller or a swamp cooler. Please don't make me explain how that works.