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CFS AIR
27-04-2016, 11:47 AM
Hi all,

Am hoping you can assist me in calculation system COP's.

I am working with the below formula but am not receiving the results i expect.

https://en.wikipedia.org/wiki/Coefficient_of_performance

I am with holding additional data as I would like you to all pass on your COP calculations and explanations on why or how you use your formula without opinion or bias.

I am trying to produce a calculator that will calculate this autonomously. Currently i am only interested in cooling only calculations and also confirm a project i am working on is producing the results that are printed.

My issue is electrical energy is used as the input unit, but where is the refrigeration unit actually incorporated into the equation? The

Cheers All
Jono

mohsixp
27-04-2016, 01:17 PM
Cooling or Heating Capacity in KW is to be divided by Power input in KW ... you will get EER or COP

Rob White
27-04-2016, 03:53 PM
.

True COP can only be worked out by using Ph charts and then the
chart has to be specific to that refrigerant.

COP can be quickly calculated by dividing the cooling capacity by the compressor power
but this is only a quick snapshot of the system and usually tends to be referred to as
Energy Efficiency Ratio (EER). EER is not true COP, true COP is a calculation between
the evaporator refrigeration effect and the compressor work done and is measured in
kJ/kg, that can then be calculated into watts.

So in answer to your question true COP can only be calculated by a fridge engineer
who fits gauges and measures the actual performance of the system and then calculates
the COP by using the appropriate ph chart.

COP varies as condition varies and a simple calculator will not be able to deal with
all the variables that are taken into account.

The best calculator I have ever used is from the Coolpack Ref utilitieshttp://www.en.ipu.dk/Indhold/refrigeration-and-energy-technology/downloads.aspx
software and
used correctly it calculates COP very effectively.