What is Internal Air & Furniture Gain on my Loads Calculation results?
Air & Furniture Gain represents gains/losses in interaction with the mass of air in the space and/or the furniture in the space. This output is listed on the Room Loads Report as well as in a Room Variable that can be viewed directly in the results file in VistaPro. It follows the convention that heat gained to the room node from the air/furniture is shown as a positive value while loss from the room node is a negative value.
The effects of the furniture mass is determined using the Furniture Mass Factor on the thermal template (found on the Space Conditions tab of the template/Space Data). A value of 1 would be typical furniture in an office for instance. A higher value can be entered for a library or space where the mass of the internal furniture is significant.
This is defined on the User Guide as:
Furniture Mass Factor The thermal capacity of objects in the space, expressed as a multiple of the thermal capacity of the air mass.
The effects of the air mass is determined using the air density defined in ApLocate.
Note: The air density defined in ApLocate is at reference condition. it will change as the temperature and relative humidity of the air changes. At most times of day, this gain/loss will be 0 because everything is balanced at setpoint. This gain/loss will typically only appear when the setpoint changes (from setback to occupied or vice versa). For example, a space is at 80F and so is the air inside it. This needs to be brought down to 75F.
