It has been said that your indoor air quality is far more polluted than the outside air. Is this true? Is it always more polluted? The answer is much more complicated. Indoor air quality (IAQ) is a dynamic ever-changing condition that affects our health, our comfort, and our pocketbooks! Trying to get to the heart of poor IAQ and its causes takes time and dedication to measure and gather the data, interpret the data, and offer a reasonable solution that is comprehensive and effective.
The three main components of indoor air quality are: Filtration, ventilation, and humidity control. This is often referred to as the Holy Trinity of IAQ. Will now discuss the three briefly.
Filtration
Many heating and cooling systems have a minimal filter that is insufficient for treating the air in your home, furthermore many of them are also insufficient to adequately protect the heating and cooling systems form loading up with dirt and causing premature failure.
A good filtration system is designed for each specific need. When we have determined that a filtration upgrade is a solution, we consider 3 things: location of equipment, airflow requirements and type of filtration needed (allergens, dust, VOC) . A good filtration system is not simply a bigger filter. This IS NOT a ‘go big or go home’ fix. Many times, that is the solution but it most cases a tested and balanced approach it best. In some case that we have seen, the filter size was just correct for the system, but the return duct leakage was terrible causing the Air distribution to the house is 10% or unfiltered spreading dust and dirt throughout the duct system and house.
Certain homes and the occupants require auxiliary continuous filtration or HEPA filtration due to severe allergies or medical conditions. This also is considered whenever an IAQ audit is being performed.
Ventilation
Ventilation is an often-overlooked aspect of IAQ and is the process of changing air in and out of the home at a prescribed amount. This is needed for several reasons.
- VOC limiting. VOCs (volatile organic compounds) can build up in the home due to off gassing materials, or chemicals. They can also come from garages and cooking appliances. VOCs have been linked to numerous health problems like asthma and cancers. VOCs are now being understood to be coming from many more products than previously known, and indoor air tests can reveal the type and possible sources. The best solution for dealing with VOCs is to exchange air at regular intervals.
- Ductwork leakage. Leaky ductwork is a major problem in homes. Leaky ducts cause an enormous burden on the HVAC system and also depressurize or pressurize the enclosure of the house causing UNWANTED ventilation in crawl spaces, attics and exterior walls The best solution to unwanted infiltrated air is to seal the ducts and seal air gaps on and around the home. Make the vents you have more efficient and then it’s possible to see if an auxiliary ventilation system is needed.
- Infiltration and exfiltration. This is the air that is able to pass in and out of little gaps and holes in the home enclosure. Air sealing is the process of closing up those gaps and joint in the framing of drywall and mechanical penetrations in the walls, joists and plates. This limits infiltration and exfiltration. The more one can control how and where the air leaks in and out, the more the inside of the home with be healthier and comfortable and even less expensive to heat and cool.
- Odor eliminating. Let’s face it, HOMES GET STINKY! Homes are boxes that are designed to hold air inside. In our home we have pets, cooking, pooping, dirty sweaty kids and so many other sources of odors. Having a properly ventilated home will help to minimize odors by exchanging the air inside the home with outside air. The is usually achieved with an Energy Recovery Ventilator (ERV) or a Heat Recover Ventilator (HRV). These devices work to both ventilate and minimize the heat load of the home.
Humidity Control
Humidity control is a vital component of your home’s indoor air quality. Humid air in sticky, clammy, damp, moist, muggy, musty, and sweaty. Humid air will aid in the growth of biologicals e.g. mold and bacteria viruses live longer damp air. Air that is too dry is staticky, arid, and some symptoms include: dry mouth, dry eyes, dry or cracking skin, nasal irritation, nose bleeds, feels cold, and worst of all
- Your home’s AC unit is designed to dehumidify as it cools the home. Sometimes the AC does not run long enough to adequately dehumidify the home. This can be a result of an AC system that is too large for the home, too much air infiltration, or the seasonal weather is not requiring many run hours but yet the outdoor air has a high relative humidity (RH). Sweating ductwork or vents is a symptom of a high RH in the home. Many homes, at times, require ancillary dehumidification to control to humidity levels.
- In the Midwest, dry air is most common during the winter months. If you are experiencing dry air symptoms for more than a month, you may want to consider a whole home humidifier. This system connects to a waterline and evaporates water into the home’s heating system. A home humidifier range in capacity and can be controlled by many of our modern smart thermostats.
