Ventilation / HVAC Collection editorial
Supply, exhaust and balanced ventilation
Mechanical ventilation strategies move air in different ways. Building tightness and climate shape the choice.
Exhaust-only
Fans remove indoor air and replacement air enters through openings and leakage paths. This strategy is simple but the source and condition of incoming air may be difficult to control.
Supply-only
Outdoor air is brought inside mechanically and indoor air leaves through relief paths. Filtration can be incorporated, but air distribution and pressure differences require attention.
Balanced systems
A balanced design mechanically supplies and extracts similar amounts of air. HRV and ERV equipment can recover some energy during that exchange. Commissioning should measure actual flows rather than relying only on the fan nameplate.
Plan the entire air path
Identify intake and exhaust positions, filters, ducts, controls, sound, maintenance access and the interaction with existing heating and cooling. Ventilation is a system design question, not just a fan purchase.
Sources and further reading
- US Department of Energy: Heat Pump Systems
- US Department of Energy: Central Air Conditioners and Heat Pumps