By Eurihea Speciale
When trying to decide how to model basements, the lines of distinction between what constitutes a conditioned vs. unconditioned basement can appear somewhat blurred. Also, once you come to the conclusion that your basement is in fact conditioned, then you must answer the question of whether or not to add the floor area to the Conditioned Floor Area (CFA). The good news is, we have come to some solid conclusions on what constitutes a conditioned vs. unconditioned basement when certain conditions are met.
The first step is to determine the level of conditioning.
The basement should be considered conditioned space and modeled as a conditioned basement if any of the following
conditions is met:
- Basement is unfinished and ducts are directly conditioning the space.
- Basement is finished and ducts are directly conditioning the space.
- Basement is unfinished, but rooms directly connected to the space are directly conditioned and are supplying air indirectly. For example, an unfinished storage or mechanical room in an otherwise finished, directly conditioned basement. In this case, as long as there has been no attempt made to thermally isolate these unfinished spaces from the finished spaces and floor above, then these spaces should be modeled as conditioned space and any equipment or ductwork located within these rooms should be modeled as being within conditioned space.