You’ve probably come across the following statistic before: we spend 90% of our time indoors, or inside buildings. The source of this oft-cited data comes from an August 1989 Report to Congress on Indoor Air Quality, which was generated by the United States Environmental Protection Agency. Fast-forward 30+ years later to spring 2020, and what the researchers failed to account for was a scenario in which we, in fact, find ourselves spending something closer to 99.9% of our time indoors due to a global pandemic and all its glorious stay at home orders.

In cities like New York, where our office is based, the density of the built environment exacerbated this condition in a pre-pandemic world. And for those weathering the crisis in the city and beyond, indoor confinement has become the new normal. This intersection of health crisis and “indoorness” has led us to focus on our role as designers in creating indoor spaces - and the direct relationship between our choices and the healthy or unhealthy interior living environments that result.

There are (3) primary categories of building “stuff” that contribute to the healthiness or unhealthiness of an interior space, and they are:

Heating, Ventilation, and Air Conditioning (better known as HVAC)
Building Materials
Furniture, Fixtures, and Equipment (commonly referred to as FF&E)

You and your electronic devices, tchotchkes, books, pets, alligators, food, clothing, shoes, dead skin cells, hair, and whatever you dragged in on your feet also have a big impact on the interior environment, but we are putting the blame for these contaminants squarely onto our clients and their post-occupancy liberties. Like that time you used spray paint to “install a mural” over your natural stone backsplash. We won’t name names, but you know who you are.

While we long ago accepted that we can’t control our clients, what we can influence are those three primary categories mentioned above. We are serious about delivering a project that will yield a high-performance space, and for us - healthy interior air quality is essential. With this series, we are starting out with #1, which takes a closer look at how we incorporate the design of air management systems (HVAC) into high performance projects.

What if I told you there is another alarming statistic from the United States EPA, and that is also from the 80’s!? Truly outrageous. This one, from the T.E.A.M. study, also examined indoor air quality and found that “concentrations of some pollutants are often 2 to 5 times higher than typical outdoor concentrations,” and this was in 1987. Between our near-exclusive relationship with our places of domicile and these stats, I’m pretty sure we should never stop wearing our N-95 masks. Ah, dystopia, you’ve arrived! (1)

And what is in this air? In addition to what you might bring in by choice or accident, it includes an airborne soup of other delightfuls, including - but not limited to - the following: VOC’s (volatile organic compounds, including formaldehyde), bacteria, molds, pollen, dust mites, cleaning solutions/products, smoke/combusted elements, carbon monoxide, natural gas, radon, ozone, pesticides, asbestos, lead, arsenic, and VIRUSES. According to the CDC, “Some biologic pollutants, such as measles, chickenpox, and influenza are transmitted through the air. However, the first two are now preventable with vaccines. Influenza virus transmission, although vaccines have been developed, still remains of concern in crowded indoor conditions and can be affected by ventilation levels in the home.” (3)

This information comes to us from 2006, well prior to the current pandemic. What we do know at this time is that Covid-19, like Influenza, can be transmitted through the air, and that crowded indoor conditions can facilitate a high level of exposure and transmission. Increased ventilation, when provided by a dedicated mechanical system, improves indoor air quality by bringing in fresh outdoor air while simultaneously exhausting the unhealthy indoor air. Coupled with appropriate levels of filtration, we use controlled ventilation systems as a tool to dramatically improve the healthfulness of the interior air supply.

When designing high performance buildings, we turn to mechanical ventilation systems for several reasons. First off, a high performance building is unconventional (for now) in a number of ways. It is extremely air tight, and this limits the infiltration of air that is common in conventional construction assemblies.

Air tightness is great until you cram a room with 20 breathing bodies and a dog, and you start to generate lots of heat and vapor. Soon it is unbearable; your walls are sweating, your people are sweating, and we need active ventilation. We, as high-performance building designers, know to anticipate this - and we plan accordingly. The dedicated mechanical ventilation system manages this, and runs constantly. It is coupled with a high-efficiency recovery system that transfers heat from the warm exhausted air to the cold incoming fresh air (winter scenario, which reverses in summer), thereby further improving the efficiency of the building.

You want this in your next project, and you want your next project to be a high-performance building with mechanical ventilation. You just didn’t know why - until now. We will help guide you through the process, and will ensure that your next building is also good for your health and wellbeing.

(1) U.S. Environmental Protection Agency. 1987. The total exposure assessment methodology (TEAM) study: Summary and analysis. EPA/600/6-87/002a. Washington, DC.

(2) The United States Centers for Disease Control & Prevention. Healthy Housing Reference Manual, Chapter 5: Indoor Air Pollutants and Toxic Materials. 2006. https://www.cdc.gov/nceh/publications/books/housing/cha05.htm