What is “Makeup Air” and Why Does it Matter for Indoor Air quality?

In nearly every residential and commercial building there’s a system known as an HVAC system. This stands for “Heating, Ventilation, and Air Conditioning.”  

In most structures, there are several appliances that push air in or pull air out including things like clothes dryers, bathroom fans, fireplaces and kitchen range hoods. These appliances depressurize the interior of the structure. Any air exhausted through mechanical systems must be replaced by an equal volume of air from the outside to re-balance the pressure. Unless airways are deliberately provided for the incoming air through mechanical design in the HVAC system, it will flow in through the path of least resistance through passive means, such as gaps around windows and doors, between framing and the foundation, or at other leaky building components.  With homes becoming more and more energy efficient and ‘tighter,’ the passive replacement of makeup air is changing how air enters the structure.

According to the EPA, there are three basic strategies to improve indoor air quality: 

1. Source Control.  This is exactly what it sounds like – seal, enclose, remove the ‘source’ of indoor air contaminants so you can control your exposure or eliminate it. For example, seal or enclose materials that contain asbestos; ensure gas stoves are functioning properly to reduce emissions; or limit/eliminate the use of pesticides.

2. Improved Ventilation.  This is especially important for short term activities that could release high levels of pollutants (i.e., painting, heating with kerosene, welding).  The act of simply opening your windows, turning on exhaust fans, or running attic fans to improve ventilation will greatly dilute or remove the pollutants. Improved ventilation can also be a successful strategy to improve and reduce problems like exposure to molds.  

Everyone has heard the phrase, ‘the house is closed up and stuffy’ or something to that effect. There’s a lot of truth to this! If you’re routinely opening your windows or actively seeking to get more fresh air into your home, that will almost always improve your indoor air quality.  New home designs take this into account and are beginning to include ways to more efficiently and regularly bring fresh outdoor air into the home. ‘This Old House’ has a great video demonstration on how this process works, and on the engineering solutions that are becoming more common in today’s homes; you can access the video here. 

3. Air Cleaners.  There are many types and sizes of air cleaners on the market, ranging from relatively inexpensive table-top models to sophisticated and expensive whole-house systems.  The effectiveness of an air cleaner depends on how well it collects pollutants from indoor air and how much air it draws through the cleaning or filtering element.  A very efficient collector with a low air-circulation rate will not be effective, nor will a cleaner with a high air-circulation rate but with a less efficient collector. Another important factor in determining the effectiveness of an air cleaner is the strength of the pollutant source. Table-top air cleaners, in particular, may not remove satisfactory amounts of pollutants from strong nearby sources. People with a sensitivity to particular sources may find air cleaners are only helpful in conjunction with other concerted efforts to remove the source.

Concerned About Your Indoor Air Quality in Your California Home?  

At Guzi-west, we perform professional testing for indoor air quality in Humboldt/Del Norte, McKinleyville, Eureka, Chico, Redding and surrounding areas. For additional services, please explore our website. Contact us today to schedule a professional testing service for your home or business. (888) 351-8189