No Outside Air in Building Load Calculations

When I run my HVAC building load calculations, there is no outside air, ventilation load, or airflow included.

Cause

In the Project Info command, if the ☐ Use Actual Supplied Airflow in Ventilation and Psychrometric Calculations box is checked, the ventilation calculations use the airflow from the diffusers inserted on the drawing.

If no diffusers are inserted, there is 0 supply airflow, and various calculations based upon a percentage of the supply airflow end up being 0 also.

The setting is included for when you want to do your ventilation calculations based upon your actual design, rather than the calculated supply airflows for the project. If you turn it on before diffusers are inserted, the calculations will not work.

Solutions

The simplest solution is to uncheck the ☐ Use Actual Supplied Airflow in Ventilation and Psychrometric Calculations box. This solution will use the calculated supply airflows for the ventilation calculation.

Alternatively, you can insert supply diffusers with airflows in your rooms using the Insert Diffuser command. This solution will use the supply airflow from the diffusers that are inserted for the ventilation calculation.