Indoor Air Quality Services

Understanding Indoor Air Quality

A typical American family generates a substantial quantity of airborne contaminants including dander, smoke, dirt and hair. Other irritants like pollen and contaminants are picked up outside and released indoors through daily movement. When combined, these unhealthy toxins are continually cycled through the HVAC system and transferred from room to room. Breathing contaminated air over an extended period of time can ultimately lead to the development of chronic respiratory illness. Even short term exposure will aggravate existing conditions like asthma and allergies.

While older homes usually have a number of unplanned fresh air pathways, they are not immune from the effects of substandard indoor air quality. Homeowners who seal envelope leaks to improve efficiency should be aware of the probable IAQ consequences. Older homes often have poorly installed duct systems with serious negative pressure leakage. When the HVAC system is engaged, a variety of contaminants are drawn into the ductwork from the attic or crawl space and blown into the living area. In quantifying the hazard, the EPA has concluded that the air inside an average home is usually 2-5 times more polluted than the air outdoors.

How to Improve Indoor Air Quality

A building with an air quality problem can be challenging to remediate, and the professionals at McWilliams & Son incorporate a variety of critical components in a complete IAQ strategy.

  • Ventilation: Mechanical ventilation devices are installed and calibrated to introduce a specific amount of fresh air into the indoor environment while exhausting stale, contaminated air. Advanced ventilators include recovery features that help recapture some of the energy lost during the air transfer process.
  • Air Humidifiers: Proper humidification is critical in maintaining healthy indoor air quality. When the air is too dry, microscopic contaminants remain airborne until they are inadvertently inhaled by someone in the building. Air with relative humidity below 30 percent can irritate nasal passages and aggravate dry skin conditions. Central humidifiers use a steam or atomized mist process to introduce moisture into the duct system in order to raise relative humidity to healthy levels. In addition to better IAQ, maintaining proper humidity will prevent wood furniture from cracking due to excessive dryness.
  • Filtration: Air purifiers are a critical element in a well-designed IAQ system. Filters trap and remove particulate matter as the air passes through the duct system. Filters are mounted directly in the air handler or inside a hinged return air grille located in a wall or ceiling. Every filter is assigned a Minimum Efficiency Reporting Value (MERV), which is used to compare the effectiveness of different filter styles. MERV measures the size and quantity of particulates that are captured as the air passes through the filter. Fiberglass filters are the least expensive, but they are ineffective at trapping smaller contaminants like pollen and contaminants. Most contractors recommend installing a media filter with a MERV value of at least seven. Electronic air cleaners and HEPA filters are exceptionally efficient at trapping small particles under one micron in size.
  • Eradication: Contaminants, fungi and other hazardous organisms thrive in a moist, dirty environment, which can be found at the A-coil in an HVAC system. A
    UV germicidal lamp positioned directly inside the coil will destroy a wide array of spores, contaminants, bacteria and other undesirable biological organisms. A UV lamp will keep the interior of the air handler cleaner, which will help improve performance and extend the life of the equipment.

Complete IAQ Solutions

At McWilliams & Son Heating and Air Conditioning, we are committed to keeping your home healthy, comfortable and energy efficient. We encourage you to explore this website to learn more about our complete line of indoor air quality products and services.