OPEN VENTS AND POOR INDOOR AIR QUAILITY

RECLAIM YOUR AIR

Air quality has been a topic of heavy conversation and concern over the last few years. It is easy to think about air quality issues with visible smoke lingering in a haze across everything, but what about once we go inside? Our homes should be a clean and safe place for us, but do you really know what you breath in while indoors?

The average American spends 90% of their time indoors and indoor air pollutants are regularly 2-5 times higher than outdoor pollutant levels (EPA, 2017). Many of the indoor air quality issues are brought about by poor conditions in the crawlspace of your home.  Nearly 50% of the air you and your family breathe comes from your crawlspace. This is due to a principle known as the Stack Effect. Outdoor air will enter the home at its easiest point of entry (improperly sealed doors and open crawl space vents) where there is lower pressure. Warm air will then rise through the home as it travels and the condensing air falls creating colder moist air. The differences between these temperatures will vary based on the difference in temperature between the interior and exterior air (Building Performance Institute, 2017). The condensation effects are even more noticeable in the crawlspace than they are anywhere else in the home due to the dramatic temperature shifts in an already moist environment.

The average temperature in a crawl space year around is 55°f. For each degree that the temperature drops when it enters the crawlspace the relative humidity (amount of water in the air) increases by 2.2 percent. During our inspections, we use a tool known as a Hygrometer to measure the heat and relative humidity in the crawlspace. On a summer day with a temperature of 88° and a relative humidity of 39%, that is a 33-degree drop in temperature with an increase in humidity of 72.6 percent.  At 100% humidity, it rains. It is very likely that your crawlspace is raining right now. This moist wet air then evaporates and collects in your insulation, and foundation supports. The wet air will linger in the crawlspace and create an ideal environment for a host of indoor irritants such as mold and increased air particulates.

Poor indoor air quality is the 4^th largest environmental threat in the United States today (EPA,2017). It has been linked to an extensive list of health issues such as; diabetes, asthma, allergies, cancer, Alzheimer’s disease, heart disease, high blood pressure, weight gain, respiratory infections and more. The increase in respiratory issues and childhood asthma rates alone speak volumes about the dangers of poor indoor air health. Asthma is the third leading cause of hospital stays in children and an average of 1 out of every 10 school-aged children have asthma (CDC, 2016). Nearly 2 million emergency room visits occur each year because of asthma-related symptoms. Fortunately, there are steps you can take to reduce the risks associated with poor indoor air quality.

Controlling indoor air quality is the most cost-effective way to control allergen-induced asthma symptoms. One of the greatest impacts you can create on controlling indoor air quality is to reduce your home’s humidity levels (Control Indoor Allergens, 2017). This will decrease dust mites as well as mold growth, a leading cause of allergic asthmatic reactions.  You can reduce humidity in many ways. You can install a dehumidifier in your home and air conditioners that recirculate air as opposed to bringing in outdoor air. Look for air cleaners and purifiers that contain a HEPA filter. This will help to reduce humidity and filter indoor allergens. While helpful, this does not do much to control the flow or quality of air coming into your home.

Here at John’s, we advocate having your crawl space inspected yearly to look for signs of moisture issues or standing water that could be exasperating the issue. These obvious moisture signs could include; caked or dried mud on top of the vapor barrier, falling insulation, white or chalky residue on concrete foundation walls, or evident puddles in the crawlspace. This is a primary location for mold and dust mites to populate and travel up into the home.  Torn vapor barriers can result in excessive moisture rising from the dirt floor and further up through the house so be sure that your vapor barrier is in one piece to ensure a solid building envelope. Proper air sealing beginning at the foundation will not only improve indoor air quality but will also reduce the amount of money spent yearly on heating and cooling costs due to greater temperature regulation. Controlling humidity will protect your family.

References:

Building Performance Institute. Stack Effect. http://www.bpihomeowner.org/blog/bpi-phrase-month-stack-effect. (2016, August) Retrieved Sept. 5, 2017, from http://www.bpihomeowner.org/blog/bpi-phrase-month-stack-effect

Centers for Disease Control. Asthma. http://www.cdc.gov/asthma/default.htm  (2016, March). Retrieved Sept 5, 2017, from http://www.aafa.org/page/asthma-facts.aspx

Control Indoor Allergens to Improve Indoor Air Quality (2015, September). Retrieved Sept 5, 2017, from http://www.aafa.org/page/control-indoor-allergens.aspx

EPA. Asthma. https://www.epa.gov/asthma. (2017, August). Retrieved Sept 5, 2017, from https://www.epa.gov/asthma