Question-and-Answer Resource for the Building Energy Modeling Community
Get started with the Help page
Ask Your Question
0

Why DB asks for the COP instead of EER for cooling systems?

asked 2021-10-29 02:26:50 -0600

updated 2021-10-29 07:29:21 -0600

I am a beginner in the DB modelling and I have a simple question: considering the efficiency of cooling systems is expressed in EER (Energy Efficiency Ratio), why DB asks for the COP (Coefficient of Performance) as if it were a heating system?

For example, if I have a multi split system with EER=3.32 (cooling) and COP=3.9 (heating), should I find out a way to convert the EER to COP or it's just a "name issue" and I can insert the EER value (3.32) where it asks for the COP of the cooling system in the DB?

Thanks!

edit retag flag offensive close merge delete

Comments

@brunaonety are you using the "Simple HVAC" model option (only defining efficiency inputs and not creating Detailed HVAC diagrams connecting components together)?

Aaron Boranian's avatar Aaron Boranian  ( 2021-10-29 07:30:46 -0600 )edit

Hey @Aaron Boranian, yes, I am.. I am using the Ideal Loads option.. but I am a bit confused because it still asking for the efficiency of the systems.. Actually, what I need from the outputs of the simulation is the primary energy for the building, so I`m not sure if I should just ignore the equipment coefficients and calculate manually the primary energy using the sensible heating and cooling results or if these results already consider in any way these system efficiencies that DB asks as an input...

brunaonety's avatar brunaonety  ( 2021-10-29 08:35:40 -0600 )edit

Does this post answer your question?

Aaron Boranian's avatar Aaron Boranian  ( 2021-10-29 12:38:06 -0600 )edit

1 Answer

Sort by ยป oldest newest most voted
1

answered 2021-10-31 05:00:12 -0600

Jim Dirkes's avatar

I think the simple answer is that EnergyPlus (for which DB is an interface) uses COP for cooling coils. This is a long-standing situation! You need to convert EER to COP. For packaged systems, this requires adjusting EER to account for the fan power - not a simple numerical conversion. You can find conversion procedures (I think) by searching this forum or contacting me privately. I'd be happy to help. (jim at fsmgmt.co)

edit flag offensive delete link more

Your Answer

Please start posting anonymously - your entry will be published after you log in or create a new account.

Add Answer

Training Workshops

Careers

Question Tools

1 follower

Stats

Asked: 2021-10-29 02:26:50 -0600

Seen: 230 times

Last updated: Oct 31 '21