The past year has taught us all a lot about invisible threats. The COVID-19 virus, however, is only one of the many things that travels about unaware to us, which is why indoor air quality is an important subject to understand.
Image: Globalheatingairconditioning.com
Let’s start with clarifying what good practices for indoor air quality are. While opening your windows to allow fresh air to circulate into your space can be beneficial, this infiltration can often bring moisture into your building, and almost always fails to satisfy filtration requirements (varied based on square footage and occupancy of a given room). Mechanical ventilation can ensure good air quality, as the air exits and enters through a controlled pathway, is filtered, and is heated, cooled, and/or dehumidified in the process.
Philadelphia has established ventilation guidelines to meet COVID-19 safety standards, particularly on filter options. Filters are rated by the MERV (minimum efficiency reporting values) scale, and the city recommends using a MERV-13 filter. However, Scott Seibert, operator of Mt. Airy Axis co-working space in Northwest Philadelphia and long-time sustainable builder, has found it often difficult to meet this recommendation, and tends to use a MERV-11 filter instead. Essentially, try for MERV-13, but you should be fine with the next-highest rated filter you can find.
The city also recommends that your system provides six air exchanges every hour, and a great sustainable option for mechanical air exchanges are Energy Recovery Ventilators (ERVs). ERVs support your HVAC system by recovering energy from outgoing air and using it to heat the incoming fresh air. Seibert recently made the decision to install ERVs at Mt. Airy Axis for this sustainability factor: “In order to get air exchanges you have to sacrifice conditioned air, there’s no way around it. But ERVs only lose around 10-12% of the conditioned temperature, as opposed to much bigger losses when you open your windows.” Therefore, not only is it an energy efficient process, but ERVs can also lower your overall energy consumption.
While this may seem like an overwhelming investment, there are opportunities to save. A great tip is that, if you know your filtration system is working, you don’t necessarily need to invest in air monitors. These sensors can be very sensitive, so particularly for areas with high traffic, they will likely be set off by particles that don’t pose a long-term issue; unless you’re going to really dive into the data these monitors collect, don’t feel bad skipping them. To make sure your ventilation is operating well, best practice for residences is to change/clean your filters each month for the first year, and then every three months after that. And make a habit of professional inspection and maintenance of your system at least once a year.
If you are looking for other ways to support positive indoor air quality, increasing biophilia in your space is a great option. Mt. Airy Axis is currently in the process of upcycling wooden pallets and filling them with plants to be mounted on the walls. Not only is indoor greenery supportive of cleaner air, they also provide stress relief and sound attenuation for your space. You can purchase small air purifiers for your space as well, which can serve as a physical reminder to think about your indoor air quality. Even when this pandemic becomes a thing of the past, it is so important that we keep taking steps like these towards good indoor air quality and protecting our health -- one breath at a time.
Written by Casey Maslan, a graduate of Boston College ‘20 and contributing writer for Boyer Sudduth Environmental Consultants.
