In our last blog about indoor air quality (IAQ), we discussed what influences IAQ, what effects it has on humans and nature, and how to create healthier IAQ in your home.
As a recap, IAQ is measured by the quantity and type of pollutants in the air within a building. The pollutants that decrease the IAQ (make the quality worse) can be anything from biological pollutants such as mold and mildew, bacteria, dust or pollen, to carbon monoxide or volatile organic compounds (VOC’s)4. These pollutants can cause a wide variety of health problems for humans and animals, from mild skin irritations all the way to damaging internal organs and causing cancer.2,5
While ventilation is just one of the many factors that affect IAQ mentioned in our previous blog, it is a multifaceted topic and requires a deeper dive than we were able to give.
We’ve already established that healthy IAQ is important, but how does ventilation impact it and what are the current shortcomings of code-standard ventilation systems?
Firstly, IAQ can be 2-5 times more polluted than outdoor air quality6; therefore, it is vital to expel a greater quantity of indoor air and intake more outdoor air to increase a building’s overall IAQ.
However, not all ventilation systems are made equally. Often, with forced air-heating and traditional air-conditioning systems, the main method of ventilation is infiltration or purely natural ventilation (opening windows)3.
This is problematic, because there will not be a great enough flow of air to expel the polluted indoor air and the outdoor air comes into the building’s envelope untreated. While outdoor air is generally less polluted than indoor air, it would be counterproductive to bring in smoky, smoggy or pollen filled air, for example, and should still be filtered before entering the building.
When mechanical ventilation is installed in a simply code-standard building, the typical system must be manually turned on and off and doesn’t have the capacity for higher airflows or continual airflows. For this reason, conscious builders like TC Legend Homes go above and beyond the less-than-optimal code-standard systems and always uses a Heat Recovery Ventilator (HRV).
HRV units allow for continual filtered airflow. They are also capable of utilizing smart technology with sensors to detect CO2 and humidity within the house, allowing the system to automatically adjust air flow.
The humidity tracking and management is a huge advantage because it creates a more comfortable environment to people, pets and indoor plants alike and helps keep mold and mildew growth in check. On top of increasing airflow and managing humidity, the HRV also contains HEPA air filters to ensure the incoming air is stripped of as many pollutants as possible.
Of course, the extra benefit to these systems beyond increased IAQ is that they “recover up to 90% of the heat and contribute to an energy savings of up to 50%.”1
This means HRV systems save money by lowering the overall energy bill, as well as decrease the building’s carbon footprint by using energy more consciously resulting in less consumption of energy, fossil fuels and other precious materials.
In all, choosing the best ventilation system can mean creating a healthier home, as well as reducing your wasted energy consumption and having a lesser impact on the environment.
Interested in learning more? Check out EPA’s Indoor airPLUS program HERE
1. Diagram depicting how a Heat Recovery Ventilator transfers heat and air. Source: AttainableHome (https://www.attainablehome.com/the-10-best-heat-recovery-ventilators/).
2“Biological Pollutants’ Impact on Indoor Air Quality.” United States Environmental Protection Agency (EPA), EPA.gov, https://www.epa.gov/indoor-air-quality-iaq/biological-pollutants-impact-indoor-air-quality. 2/10/2022.
5“Volatile Organic Compounds’ Impact on Indoor Air Quality.” United States Environmental Protection Agency (EPA), EPA.gov, https://www.epa.gov/indoor-air-quality-iaq/volatile-organic-compounds-impact-indoor-air-quality. 2/10/2022.
6 Wallace, Lance A., et al. Total Exposure Assessment Methodology (TEAM) Study: Personal exposures, indoor-outdoor relationships, and breath levels of volatile organic compounds in New Jersey. Environ. Int. 1986, 12, 369-387. https://www.sciencedirect.com/science/article/pii/0160412086900516.
Impact of Eco-Conscious Living Series: Indoor Air Quality
Just as you may think about the poor outdoor air quality on a smoky day or the smog that surrounds large cities, every building has its own body of air with varying degrees of quality and pollution that make up the indoor air quality (IAQ). IAQ is incredibly important for your own health and is, unfortunately, frequently under accounted for by mainstream building practices. It is, however, an attribute of eco-conscious building techniques for its impact on human and animal health, interlinked outcome of house longevity, and subsequent decrease in environmental footprint.
Taking a deeper dive into what IAQ actually is, IAQ can be anything from biological pollutants such as mold and mildew, bacteria, dust or pollen, to carbon monoxide or volatile organic compounds (VOC’s)5. Each pollutant effects humans, animals and the environment differently and the effects on humans can also vary depending on personal sensitivities. Exposure to just biological pollutant could lead to “skin irritation, sneezing, watery eyes, coughing, shortness of breath, dizziness, lethargy, fever, and digestive problems”1. Other pollutants, such as VOC’s, can cause more severe symptoms such as “eye, nose and throat irritation, headaches, loss of coordination and nausea, damage to liver, kidney and central nervous system,” with some VOC’s known or suspected to even cause cancer in humans or animals6. For information about all the individual indoor pollutants and their sources, visit https://www.epa.gov/indoor-air-quality-iaq/indoor-pollutants-and-sources.
Many of these pollutants are unavoidable as they can occur naturally, but we can take steps to reduce them to levels that will be less harmful or eliminate them almost entirely. If you hire TC Legend Homes, then before you even step into your house, we have already been working on increasing your home’s IAQ by using low toxicity products such as SIPs, low/zero VOC paints and finishes, low toxicity flooring and more. The SIPs we use eliminate the ozone depleting chemicals HCFCs and CFCs, as well as reduce moisture in between the walls that lead to mold growth.2 This, accompanied by the superior heating and ventilation installed, will set your home up for much healthier air. The next blog post in this series will discuss the details of ventilation and its impact.
Once moved into your new home, it is still important to take daily steps to maintain a healthier IAQ. Be sure to vacuum and dust regularly, clean fabric items frequently, reduce household clutter3, avoid harsh cleaning products, maintain a lower humidity level, repair leaks, run your exhaust fan during and after showering, maintain your ventilation system and change the filters frequently4.
Many eco-conscious building methods and results are interconnected, including IAQ, house longevity and environmental footprint. The nature of obtaining and maintaining good IAQ, means ensuring your home is being fixed of any issues which will result in the deterioration of your home and therefore cause indoor pollutants such as mold and mildew. Immediately fixing smaller issues that come up, like leaks or a filter in need of changing, will decrease the likelihood of the issues becoming so large that it is irreversible or will require more replacements to the system or surrounding area in the future. To this same note, upkeeping your home regularly and fixing issues as soon as they turn up, means using less resources in the long run, as replacement will be less frequent. As we know, using less resources helps to lower your overall carbon footprint. Moreover, maintaining good IAQ requires use of less toxic materials including those containing toxins and pollutants that are harmful to the environment such as greenhouse gases like VOCs or potent chemicals like pesticides. This in turn reduces the negative impact on the environment.
Taking all these steps to obtain and maintain your IAQ, will not only help you and your family’s health, but help reduce pollution outdoors and increase the longevity of your home.
Want to learn more about how smoke affects indoor air quality? Check out EPA Indoor Air Quality information and their recommendations for wildfire season HERE
Written by: Nicole Miller
Sources:
1“Biological Pollutants’ Impact on Indoor Air Quality.” United States Environmental Protection Agency (EPA), EPA.gov, https://www.epa.gov/indoor-air-quality-iaq/biological-pollutants-impact-indoor-air-quality. 2/10/2022.
2“Building With Sips Creates Healthier, More Comfortable Interiors.” Insulspan, https://www.insulspan.com/advantages/health-comfort/. 3/2/2022.
3“Easy ways you can improve indoor air quality.” Harvard Health Publishing, Harvard Medical School, https://www.health.harvard.edu/staying-healthy/easy-ways-you-can-improve-indoor-air-quality. 2/10/2022.
6“Volatile Organic Compounds’ Impact on Indoor Air Quality.” United States Environmental Protection Agency (EPA), EPA.gov, https://www.epa.gov/indoor-air-quality-iaq/volatile-organic-compounds-impact-indoor-air-quality. 2/10/2022.
It’s a dark winter evening. You leave the house and as you emerge outside you feel the cold, fresh air and you pop up, feeling sharp, awake, fresh and lively.
The operative word is ‘fresh.’
Sure, the air is cold and that helps, but in reality we’ve been building sealed buildings since the 80’s with gasketed doors and windows, old drafty houses are becoming fewer. Modern housing is very well air sealed to prevent energy loss. However, the ventilation systems have not been developed and installed at the same pace as the air sealing.
So we need to get fresh air into our houses. We’ve needed more fresh air since the 80’s and as a population we’ve become used to poor air quality.
Yes building code does require ventilation, but often it’s switched and folks don’t hit those switches. We need ‘continuous ventilation’.
The best system is the Heat Recovery Ventilator (HRV). The outgoing ‘dirty’ air is blown out of the house, but before it leaves the heat is stripped out and imparted into the incoming ‘clean’ air. The HRV is always on, and has filters so the air really is clean. HRV’s can be 95% efficient, and in the Lake Stevens house the HRV reduces the maximum building heat load from 14,450Btu/h to 12,800 Btu/h.
The Zhender HRV’s we fit can have Co2 sensors, so they bring in more air when more folks are inside breathing. Also humidity sensors so moist air, the “building-killer,” is automatically removed. Manual boost switches and wireless control are all becoming standard.
The air is still dirty!
Ted Clifton, Co-Owner and Founder of TC Legend Homes, has an air quality monitor in his home. Cooking is a real problem.
The screenshot from Ted’s Footbot monitor shows that it took over an hour for the 200cfm balanced fan to remove the particulates down to the monitor-defined safe level. Ted was cooking hash browns and eggs on a Saturday morning. It is important to note that Ted’s 200cfm fan has a second 200cfm intake fan so it’s a balanced system and can be interpreted as a 400cfm fan.
The lesson is that range hoods are critical to maintaining indoor air quality and should really be sensor-activated. At TC Legend Homes we will be specifying more powerful units; perhaps 800cfm as standard. The presence of particulates indoors is linked to asthma.
The arrival of home automation will easily address this problem and a quick Google search for wireless range hoods yielded plenty of cost-effective models.
The next part of the test is to cook the same hash browns and eggs next Saturday, leave the range hood off, then we’ll see how long it takes a modern super home (Ted lives in the Bellingham Powerhouse) to clear the air with just the HRV.
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