COP and EER for Air-Cooled Chillers

If you're looking for definitions of these acronyms, then I'd suggest starting out with this HVAC Glossary.

Are you really writing to us from Iran?

Yes i am really writing from Iran I have small factory to produce HVAC equipment like All Valves and fittings used for steam boiler/level control/burners control/ I purchased a Italian Chiller for factory 200 ton and COP was questions for me because in academic EER is = COP. 3.41 for that chiller this nomber is 8.56 and 8.56Divided 3.41 / the nomber we get it is 2..... and it is very low and show the chiller is not good?

What is the temperature of the water (or brine) leaving the chiller? For air conditioning, it might be about 45-50°F (7-10°C), with a COP of about 3. For other purposes, it might be colder, and the COP will be lower. 8.56/3.41 ≈ 2.51.

The COP and EER are fairly closely related. The higher either value is, the better the energy efficiency. However, the higher these values, usually the higher the cost. Thus you need to check how quickly the higher initial cost can be recovered by the reduced operating expense. In other words, economic analysis.