Dear all,
I am currently developing an energy model for a mall building. In this mall there are hundreds of small retail units, each including a tiny service toilet for employee use (<5m2).
In such a large scale, I am seeing how my model thermal zones are x2 because of these small toilets, but I cannot find any standard of indication/recommendation on how to model these spaces or whether they should be merged with the zone they serve.
Does anyone have had a similar issue? do you know any standard that defines these spaces or how to deal with them? I believe since the size and the loads are not significant they should be merged along with the areas that provide service, which on the other hand is a conservative scenario energy-wise since these areas will have a larger load overall.
We are trying to simplify the model since the simulation time will increase considerably the more the number of zones, and thus the complexity of any consequent data post process.
I will be grateful to hear about previous experiences in this matter or similar.
Thanks
Julio Fernandez Amodia
5 thumbs up
February 24, 2023 - 9:11 am
Anyone?
I have found this addenda for LEED 2009 that seems to address something similar to the description above.
https://www.usgbc.org/leedaddenda/1645
Have you had small rooms as part of a larger thermal zone before? how have you addressed these?
Thanks
Camilo Velez
PrincipalSimgea
15 thumbs up
February 27, 2023 - 10:06 am
Hi Julio,
From our experience, as with most things related to energy modeling, it depends, but considering the size of your project, the use of that space and the size of those restrooms I would merge it with the adjacent space. Now, if you were to just be modeling one retail unit and/or are doing another kind of assessment about these spaces, i.e. thermal comfort, retrofit, etc, I would split it.
Regarding guidelines, ASHRAE 90.1, and its User Manual, should be the starting point, but there are other sources out there such as PNNL, and also forums such as unmethours. But at the end of the day, a lot of times is about a judgment call, and keeping things fair between baseline and proposed models, so you can have an apples to apples comparison.
Hope that helps.
Julio Fernandez Amodia
5 thumbs up
February 27, 2023 - 10:32 am
Thanks Camilo.
I understand that there isn't one single formula for this issue and several approaches might be acceptable if they respond to the credit's main objective, whether thermal comfort or energy performance.