Honeybee simulates a zero-degree room or sets up a zero-degree cooling source

Yixin · July 7, 2022, 1:41am

Dear friends, I have a problem with the simulation. I want to simulate a cold storage in the building interior, but the regular air conditioning settings cannot set the cooling below 20 degrees. I need to set up a room with a cooling source of minus 3 degrees, or a cooling source of minus 3 degrees inside the room. Can Honeybee’s simulation achieve this?

kentakahas · July 8, 2022, 1:49pm

I believe you cannot model refrigeration systems in native Honeybee since it only has basic air conditioning equipment for typical operation ranges.

Depends on what you are trying to do, but your best bet is to use EnergyPlus or OpenStudio’s refrigeration systems. Links to some Unmet Hours post for examples:

chris · July 12, 2022, 2:14pm

You can model this condition right now using an Ideal Air System. You just need to make sure that you put the cooling supply air temperature of the system low enough using the HB Ideal Air component.

But I know that people would like to use the actual refrigeration systems that OpenStudio supports and so I opened an issue for this and I will get to it eventually:

github.com/ladybug-tools/honeybee-energy

Add support for Refrigeration Systems

opened 02:07PM - 12 Jul 22 UTC

chriswmackey

new development

It seems like we should add support for this and it should function similarly to… how HVAC and SHW systems function in the schema. Actually, it might be best to just enable people to swap out the HVAC with a refrigeration system template. Then, we can parse in the walk-in refrigerators that are in the standards gem as Program Types and the refrigeration system will just try to meet their cold setpoints: https://github.com/NREL/openstudio-standards/blob/master/lib/openstudio-standards/standards/ashrae_90_1/ashrae_90_1_2019/data/ashrae_90_1_2019.refrigeration_walkins.json This is probably best as it will involve very minimal changes to the schema and there likely won't be a need to ever heat a walk-in refrigerator. Maybe we even put them under Heat/Cool HVAC templates and the refrigeration templates are kinda like "cooling only" systems (much like the "heating only" systems that are already under this section).

In the meantime, if you need support for this, you’ll either have to edit the OSM in the OpenStudio App or write a short script to add the refrigeration system with a Measure or with the OpenStudio SDK inside a GHPython component like so.