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

Glycol Cooling coil with Temperature below zero in E+. How to model?

asked 2018-12-08 03:11:03 -0600

updated 2018-12-11 15:14:05 -0600

I have to model a Glicol Cooling system where the Glicol supply temperature is around -5°C. The IDF editor tells that the Water Coil works only for temperature above zero. There is a way to overcame this limitation?

edit retag flag offensive close merge delete

1 Answer

Sort by » oldest newest most voted
0

answered 2018-12-11 15:20:15 -0600

EnergyPlus supports glycol plant loops, and the water-side of Coil:Cooling:Water is able to handle temperatures below freeezing. But the chilled water coil model has no provisions for frost on the air side, so it's not valid below freezing. For cold-temperature applications, you need to use the refrigeration objects, starting with Refrigeration:AirChiller.

edit flag offensive delete link more

Comments

Regarding the Coil:Cooling:Water I'd want to ask you some more details: If I follow with the model of glicol plant loop and water coil, the simulation will end with error, or I will get the results but they are wrong only because the energy use for defrosting are not accounted? Or the heat balance on the coil will be wrong with very unrealistic results due to the model formulation? In my case, the defrosting is done with water spraid on coil pack and I don't really care about the energy impact of this process since is meaningless in my application.

Your experience will be helpful

Marco Giuliani gravatar imageMarco Giuliani ( 2018-12-13 10:09:23 -0600 )edit

A quick check of the coil source code does not reveal any error messages related to freezing temperatures, so it may work fine and simply remove moisture from the air like normal. Or you may run into some psychrometric function problems. The only way to know is to try it.

MJWitte gravatar imageMJWitte ( 2018-12-14 13:29:11 -0600 )edit

And be sure to add output variables for all of the node conditions entering and leaving the coil so you can verify if energy is conserved and if the psychrometrics look reasonable.

MJWitte gravatar imageMJWitte ( 2018-12-14 13:30:09 -0600 )edit

Your Answer

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

Add Answer

 

Question Tools

1 follower

Stats

Asked: 2018-12-08 03:11:03 -0600

Seen: 37 times

Last updated: Dec 11