How to Maintain Good Indoor Air Quality
in the time of the Coronavirus
There's a lot of stuff floating around in the air in our homes. Allergens, dander, dust mites, VOCs, chemicals from our household cleaners, mold, bacteria and other particulates. Some of these are just part of life. Plants release pollen, moisture builds up during a shower, dogs and cats slough off dander, dust accumulates, and we have to clean the house to keep our families safe and healthy. Some of what's in our air is the result of home improvement like the VOCs that come off of fresh paint, adhesives, flooring, and even new furniture.
And then there are viruses like COVID-19. According to an October 5th statement by the CDC the COVID-19 virus is transmitted by both larger and smaller (aerosol) droplets. So, unless you're always wearing a mask with very high filtering capabilities or standing more than 6 feet from someone in an outdoor space, there will be risk. VOCs, chemical fumes, and bacteria can also float around in the air, long after we've finished painting or cleaning. But fear not.
A well-planned mechanical ventilation system will exhaust air out of your home from the most polluted rooms (think kitchen, bathroom, home gym) and bring fresh, filtered air into your home. Proper ventilation, according to the Home Ventilating Institute, is the forced movement of air into and out of a building (your home for the purposes of this article). This is often called mechanical ventilation because a mechanical system (such as a bathroom fan, range hood, energy recovery ventilator or air handler - often attached to the furnace) moves the air into and out of the home. Proper ventilation is key to having a healthy home and, while ventilation doesn't provide 100% protection against airborne pollutants and viruses, it limits your exposure and continuously provides you with fresh, healthy air.
There are three basic ways to achieve whole home ventilation.
- Exhaust Ventilation – This is accomplished, typically, with a quiet, efficient bathroom fan that is set to run continuously at a minimum CFM, thereby drawing stale, polluted air out of the home which is replaced naturally. Most every home has a bathroom fan because building codes normally require it. But not every home has a quiet fan. And not every fan meets everyone's needs or desires. It's possible that the fan in your bathroom has been there for a while and is starting to show signs of age like a yellowed cover or a rattling sound. Updating that fan with an ultra-quiet Ultra Green(tm) series fan will give the room superior ventilation with barely noticeable sound. Or, maybe you're tired of lugging a portable speaker into the bathroom so you can relax to some music or catch up on your latest podcasts. A fan with a built in Sensonic Bluetooth speaker can take care of that issue.
- Supply Ventilation – With supply ventilation, fresh air from outside is pushed into the home via a dedicated supply fan that is ducted into the HVAC return trunk. These fans contain filters and can often offer high level MERV filtration to clean the air before it comes into the home. By forcing fresh air into the home the fan helps dilute the concentration of pollution, bacteria, and viruses and forces that polluted air out of the home.
- Balanced Ventilation - Balanced ventilation is the healthiest and usually the most energy efficient ventilation solution. With this type of ventilation - sometimes called a Fresh Air System – stale and polluted air is exhausted out of the home while fresh, filtered air is brought into the home. It's called balanced ventilation because the volume of air entering matches the volume of air leaving. As with the supply fan, Fresh Air Systems have great filtration options that can filter out viruses. The most common Fresh Air System options are HRVs (heat recovery ventilators) and ERVs (energy recovery ventilators). Both systems have two fan mechanisms: one for outbound air and one for inbound air. Both HRVs and ERVs pass the two airstreams through an air exchange core. HRVs transfer the heat lost during the air exchange and ERVs transfer both the heat and humidity levels. In either case you end up with a house filled with fresh air that is pre-tempered , which puts less load on your furnace, air conditioner and filters.
Photo by CDC on Unsplash