HVAC = Heating, Ventilation and Air Conditioning.
We are resonably good at remenbering to do the heating and air conditioning part but we are hopeless at thinking about the ventilation part.
Ventilation is a crucial part of building performance. Without it the system fails.
Remember the mantra of “Build tight and vent right.” It is important for the health of the building and the health of the occupants.
If we do an HVAC job without the ‘V’ we end up with a HAC job.