Heating and Cooling Air Balance is a Tightrope Walk
Pressure balancing is probably the least understood, yet one of the most important, services provided by heating and cooling companies. Bottom line, it’s all about achieving the right balance of negative and positive air pressure. Too much of either can create problems. A neutral system is ideal and what is ultimately needed for the healthiest air inside a home. Neutral will also result in lower utility bills since conditioned air is not escaping through cracks and crevices and outside air isn’t making its way indoors. A neutral to slightly positive air pressurization will provide the most comfortable atmosphere and prevent outdoor contaminants from entering the home.
An energy audit can determine if your home has positive or negative air pressure, what’s causing it, and how the home can be brought to neutral. Audits should be done by honest, certified technicians who work at established heating and cooling companies.
The condition in which too much air is drawn into your home and not enough allowed to pass through is called negative pressure. This means that unfiltered and unhealthy air has a welcome mat waiting for it. Outside air contains many pollutants and, especially here in the desert of Arizona, dust has a way of infiltrating even the cleanest of houses. All that outside air being sucked into your home because of a negative pressure system can lead to asthma and allergy problems and other health risks caused by dust, mold, carbon monoxide, and other airborne contaminants.
Some of these issues can be addressed by simply sealing windows and doors with weather stripping and caulking, especially if the home is older, though any leaks in ductwork should always be repaired before adding more insulation.
When conditioned air is allowed to escape through windows, doors, into your attic, and beyond, this is called positive air pressure. All the warm or cool air your system just worked so hard to create goes right out of the house when there’s positive air pressure. Just as in a home that has negative pressure, weather stripping, caulking, and proper insulation are important requirements towards reaching neutral air pressurization. Beyond that, installing baffles, vents, transfer grilles and ducts, or return ducts, or closing existing ones, may be the answer, depending on each room’s pressure issue.