Mechanical ventilation services in Baltimore, MD

Ventilation is necessary to remove old, stale air in buildings and replace it with new, fresh air. Mechanical ventilation allows for controlled air exchange and helps to moderate internal temperatures, reduce moisture accumulation, and reduce odors.

There are three types of whole-house mechanical ventilation systems: supply-only, exhaust-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.

Supply-only ventilation consists of a fan drawing outdoor air into the house. Indoor air escapes through the building enclosure and exhaust fan ducts. Supply-only can be a dedicated system or, more commonly, a central-fan integrated (CFI) system. With a CFI system, outdoor air is ducted to the return plenum of an HVAC air handler that draws in and distributes the outdoor air.

Exhaust-only ventilation is essentially the opposite of supply-only ventilation. In an exhaust-only system, air is drawn out of the building. This relies on indoor air entering through openings such as doors and windows. This system also includes a central fan.

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 can include a heat recovery ventilator (HRV) or an energy recovery ventilator (ERV). An HRV transfers a portion of the heat between the exhaust air and the fresh air; an ERV transfers heat and moisture. An HRV or ERV provides the benefits, but limits the drawbacks, of supply-only and exhaust-only methods. Commonly, an HRV is recommended for dry, cold climates and an ERV is recommended for moist, warm climates.

There are pros and cons to each type of mechanical ventilation – one type may work better for the situation than another type. Consulting with our professionals can help improve your building’s air quality. Contact us today.