I am modeling a 35,000 sf cafeteria that has seven walk-in coolers/freezers with total floor area of about 1700 sf. They are in the basement and first floor of the building. In Energy Plus, the refrigeration model accounts for the energy load on adjacent spaces and recognizes the impact of door openings, air exchange with adjacent spaces, condenser location, and heat exchange through the walls of the unit with the adjacent spaces. It also will model condenser heat recover, which is a feature that will be included in the Proposed Design. However, it is my understanding that there is no requirement (in Energy Plus or ASHRAE 90.1) to model the walk-in boxes physically, meaning they do not have to be represented as spaces in the model. But they occupy space within the building and I think the floor area they occupy should be physically modeled and designated as unconditioned space, with no ventilation required and the walls, floor, and ceiling areas set as adiabatic. But, one of the freezers is in a section of the basement next to three underground exterior walls. This makes me not as sure about making the wall adiabatic.
Since walk-in coolers and freezers are process loads, so I would assume that the interior lighting is considered process load as well. The walk-in floor area would be excluded from calculating the baseline lighting power density allowance.
Are my assumptions correct? Comments, corrections, and guidance are most appreciated!
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5906 thumbs up
November 2, 2016 - 3:56 pm
You are allowed to model these kinds of things different ways as long as you can demonstrate that the way you are modeling it is thermodynamicly the same as the actual condition. So you are not required to model it in place but you are required to demonstrate that your modeling method accounts for all the effects of modeling it in place. Sounds like you have some doubts about that and I agree.
I don't think the lighting is process. I think these are storage spaces.
Julio Fernandez Amodia
5 thumbs up
February 13, 2024 - 9:03 am
Hi,
I am dealing with a similar issue. I have an energy model for LEED v4 compliance with ASHRAE 90.1 2010 and I can't find any guidelines/requirements about how to model cold rooms.
Is there any guideline/recommendation about how to address this?
Thanks
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5906 thumbs up
February 13, 2024 - 10:05 am
Walk in coolers like in the example above or more like a refrigerated warehouse? For a refrigerated warehouse here is a guide - chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/https://www.gcca.org/legacy-system/protected-docs/protdocs/EnergyGuideli...
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5906 thumbs up
February 13, 2024 - 10:06 am
Walk in coolers like in the example above or more like a refrigerated warehouse? For a refrigerated warehouse here is a guide - chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/https://www.gcca.org/legacy-system/protected-docs/protdocs/EnergyGuideli...
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5906 thumbs up
February 13, 2024 - 10:20 am
Walk in coolers like in the example above or more like a refrigerated warehouse? For a refrigerated warehouse here is a guide - chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/https://www.gcca.org/legacy-system/protected-docs/protdocs/EnergyGuideli...