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IamIan · 10-13-2012, 08:03 AM

EER ratings = BTU Output / electrical Watt Input
The higher the EER the more BTUs per Watt of input = more efficient

Coefficient of Performance ( COP ) is a unitless measure of the efficiency = Watt of heat output / watt of electricity input

COP * 3.412 = EER

SEER uses an adjustment to the EER to try to account for operating differences throughout the year and different conditions... Common rule of thumb about SEER * 0.875 = EER... but the specifics of conditions and design can and do deviate from this.

A COP of 1 = 1 Watt of heat per 1 watt of applied electrical energy ... This would also be an EER of 3.412 ... generally about a SEER of ~3.9 ... this would be any resistive heating element based unit that converts 100% of the applied electrical energy input into heat energy output ... in practice it's never 100% ... but that is the best any resistive heating unit can do.

On the other hand ... many heat pumps are able to move heat from one place to another far more efficiently ... Getting a heat pump with a SEER above 4.0 is not very hard to do at all ... 12 and above is also not particularly difficult.

A Heat pump that is operating with a SEER of about 12 will move 4x as much heat energy from point A to point B than that resistive heating element based space heater can.

So ... if you are looking for a more energy efficient form of space heating ... and you don't mind a bit of a project ... you could try to convert a window type AC unit which is a heat pump often with SEERs of 10 , 12 or better ... and just switch it around ... heat pumped into the room ... instead of pumped out of the room ... the crucial part of that would be the sealing up of the interface so you don't have cold air leaking back in ... and of course be mindful that the hot side will get hot ... etc.

Also keep in mind ... it most likely is not the design intended purpose of the units ... so performance will likely not = the advertised summer SEER ... and you may have to include a few design adjustments of your own.

10-13-2012, 08:03 AM	#6 (permalink)
IamIan Master EcoModder Join Date: Dec 2010 Location: RI Posts: 692 Thanks: 371 Thanked 227 Times in 140 Posts	EER ratings = BTU Output / electrical Watt Input The higher the EER the more BTUs per Watt of input = more efficient Coefficient of Performance ( COP ) is a unitless measure of the efficiency = Watt of heat output / watt of electricity input COP * 3.412 = EER SEER uses an adjustment to the EER to try to account for operating differences throughout the year and different conditions... Common rule of thumb about SEER * 0.875 = EER... but the specifics of conditions and design can and do deviate from this. A COP of 1 = 1 Watt of heat per 1 watt of applied electrical energy ... This would also be an EER of 3.412 ... generally about a SEER of ~3.9 ... this would be any resistive heating element based unit that converts 100% of the applied electrical energy input into heat energy output ... in practice it's never 100% ... but that is the best any resistive heating unit can do. On the other hand ... many heat pumps are able to move heat from one place to another far more efficiently ... Getting a heat pump with a SEER above 4.0 is not very hard to do at all ... 12 and above is also not particularly difficult. A Heat pump that is operating with a SEER of about 12 will move 4x as much heat energy from point A to point B than that resistive heating element based space heater can. So ... if you are looking for a more energy efficient form of space heating ... and you don't mind a bit of a project ... you could try to convert a window type AC unit which is a heat pump often with SEERs of 10 , 12 or better ... and just switch it around ... heat pumped into the room ... instead of pumped out of the room ... the crucial part of that would be the sealing up of the interface so you don't have cold air leaking back in ... and of course be mindful that the hot side will get hot ... etc. Also keep in mind ... it most likely is not the design intended purpose of the units ... so performance will likely not = the advertised summer SEER ... and you may have to include a few design adjustments of your own.