Question-and-Answer Resource for the Building Energy Modeling Community
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In my opinion the internal mass needs to be considered in a warehouse since it will represent a strong dampening factor to temperature changes. So the approach of calculating the surface area and mass (or representative construction and materials) makes sense to do.
Unfortunately, I think warehouses and the internal mass that is represented inside are also pushing another assumption that is used in building energy simulation which is the "well stirred zone" if circulation fans are not used. The idea that the temperature is uniform throughout a zone when zones are the size of warehouse zones is probably not very accurate. You may have experienced how some aisles in a warehouse can seem much colder than others. Given that, not all the surface is really actively interacting at the same temperature so perhaps some of surface area of the internal mass should be adjusted downward.
I am not aware of any specific reports that have investigated this. One of the few places that I know that describe modeling assumptions for warehouse internal mass is PNNL-17056 "Technical Support Document: The Development of the Advanced Energy Design Guide for Small Warehouse and Self-Storage Buildings" by Liu, et al. (See section 7.3.4). It shows some calculations for internal mass but not much other discussion on the topic.
