According to the U.S. Environmental Protection Agency (EPA), the concentration of air pollutants inside the typical American home is two-to-five times greater than what the average American is exposed to outside, and in many homes pollution density is much higher.
The good news is that this problem is solvable, through an expanded use of ventilation.
What is Ventilation and Why is it Important?
Ventilation means air movement, specifically the removal of stale, polluted indoor air and its replacement with cleaner, fresher air from outside.
Indoor living spaces contaminated with dust, dirt, moisture, pet dander, pollen, mold spores, bacteria, smoke, fumes from nearby roads or adjacent garages, chemical traces from cleaning products, bathroom and kitchen odors, and other sources of airborne unpleasantness require frequent ventilation. But if your home is like most, chances are your ventilation is inadequate.
Our homes are a refuge. Nevertheless, maintaining acceptable air quality inside of them is a constant challenge. Without proper ventilation unclean air can fill your lungs and nasal passages, putting you and your family at risk for allergy attacks, asthma, skin problems, bacterial infections, and eye, nose and throat irritations.
Ventilation is preventive medicine, and if you neglect to provide proper ventilation in your living area you can pay a heavy price for your neglect.
Three Types of Home Ventilation and How They Can Work for You
There are three sources of ventilation that can clear your home’s air: natural ventilation, mechanical ventilation, and air infiltration or exfiltration. The first two can be powerful allies, while the latter can help you as well if you give it a little boost.
Windows and doors (especially screen doors) are your natural ventilators, and if they are kept open and unblocked they can do good work. To increase natural venting efficiency, you should keep windows and doors open on opposite sides of the home and on separate floors. This will draw air through and maximize air flow.
To boost flow further, electric fans can be strategically placed near windows to increase the speed of the air’s movement.
If you can’t keep your windows open all year long, you can supplement natural ventilation with one of four mechanical ventilation system options:
- Supply ventilation systems. Supply fans bring fresh air from the outside through intake vents placed at various locations around the home’s perimeter, piping it throughout the home via ductwork. Supply ventilation systems aren’t suitable for cold climates, since they can pressurize indoor air and increase indoor heat loss through air leakage in winter.
- Exhaust ventilation systems. These systems use exhaust fans to expel air through outtake vents, depressurizing indoor spaces and making it easier for fresh air to re-enter the home. Exhaust ventilation systems are not ideal for hot, humid climates, where penetration of outside air can create moisture problems on the interior of the home.
- Balanced ventilation systems. Exhaust and supply fans are both installed and operated in unison, to keep air constantly flowing in and out. Because of their four-season efficiency, balanced ventilation systems work well in any climate.
- Spot ventilation. Exhaust fans placed in bathrooms, kitchens or garages can ventilate specific rooms vulnerable to odors or other types of contamination.
Mechanical ventilation systems must be properly sized to meet the ventilation needs of each individual home, and trained indoor air quality professionals can help assist with that task.
Infiltration and Exfiltration
Infiltration and exfiltration refer to air leakage into and out of your home through cracks, holes, and crevices in walls, floors and ceilings, or under and around doors and windows. This air movement helps but is not sufficient to fully cleanse indoor air, and you should supplement its action by purchasing air cleaners or air purifiers.
Air cleaners use fans to pull in air, which is then passed through a filter to remove microscopic (or larger) particle contaminants before the air is recirculated into the room.
Air purifiers work similarly, and some models use filters. But other models use ultraviolet light (UV) to neutralize living bacteria and other microorganisms, and still other models use an absorbent material (often activated carbon) to “soak up” the pollen, spores, dust particles, chemical traces and so on that can make your home’s air virtually unbreathable.
Air cleaners and purifiers come in a broad range of sizes, capacities and prices, depending on your needs and preferences.