Central Ventilation System

Different Types Of Mechanical Ventilation

There are three types of whole-house mechanical ventilation systems: exhaust-only, supply-only, and balanced. Each system uses a combination of fans, ducting, dampers and controls, and they each have different pros, cons, and costs accompanying them.

Exhaust-Only Ventilation:

Exhaust-only ventilation tends to consist of a fan, commonly a bath fan, exhausting indoor air. Outdoor makeup air is drawn into the house through leaks in the building’s enclosure.

Supply-Only Ventilation:

Supply-only ventilation consists of a fan drawing outdoor air into the house. Indoor air escapes through the building enclosure and exhaust fan ducts.

Balanced Ventilation:

Balanced ventilation systems are a combination of exhaust and supply methods roughly providing equal indoor exhaust and outdoor supply air flows (e.g. an exhaust fan combined with a supply fan or passive inlet vents).

A balanced system could include a heat recovery ventilator (HRV) or an energy recovery ventilator (ERV).