Section 5.2 HVAC (Heating, Ventilation and Air Conditioning) reviews the basics of what insulators and air sealing contractors should know about HVAC units and their integration into the air barrier and 'house as a system'.
SPECIAL NOTE: HVAC work is a regulated trade and should ONLY BE DONE by licensed technicians. Maintaining airtightness can be planned ahead of time - involve your HVAC technician in the planning process to make sure it's done properly.