Posted on July 7, 2021 by Ceco Building Systems
According to the EPA, on average, Americans spend upwards of 90% of their time indoors. Between work, school, shopping and relaxing at home, the vast majority of our time is spent breathing stale, indoor air. The EPA also reports that some pollutants are as much as five times more concentrated indoors than they are outdoors.
As pandemic restrictions lift and people across the country head back to the office, return to school and venture back into indoor public spaces such as movie theaters, museums and retail establishments, indoor air quality is top of mind for all of us.
But air quality isn’t a simple, single-variable concept. It’s a dynamically changing interplay of many different factors. The good news is many of those factors are within your control.
The Energy Crisis
Up until the 1970s, there weren’t strong and consistent regulations on building energy efficiency. This changed after a series of energy crises in the 70s and 80s which led to regulations which increased the thermal efficiency and air-infiltration of the building envelope. Thermal efficiency, as measured by r-value, is the insulation rating of a system, whether it is the wall, floor, ceiling, roof, etc. Air-infiltration, as measured by air leakage, is outside air that enters a building uncontrollably through cracks and openings.
Ever since, both the national and local codes have steadily increased the thermal efficiency and air-infiltration of the building envelope – especially in Canada’s northern climate zones. Beyond regulations, building tightness has been incentivized by the R-2000 Program and the EnerGuide Rating System from Natural Resources Canada. This has resulted in structures that are more and more airtight.
Air tightness helped buildings maintain more comfortable indoor temperatures better than ever – and more efficiently than ever. However, this air tightness has been detrimental to indoor air quality, because it means virtually no fresh air comes in. Siet ‘Foeng’ Tjong, Ceco Head of Research and Development explains, “We generally do not like to have any leaks, whether it’s water, vapor or air leaks into the building. But in some cases that does create a problem with indoor air quality.”
We don’t often think of indoor air as necessarily being unhealthy, but it has the potential to harbor all kinds of harmful materials. As Joseph Dachowicz, Ceco’s Vice President of Marketing for Commercial Business, points out, “Buildings are filled with all kinds of man-made materials you’re just basically breathing in all day.”
Tjong agrees, “When you have a building that is super tight, it also creates a lot more challenges for the HVAC engineer to provide balanced indoor air quality,” she said, ”and it creates a lot more load and requirements on the HVAC system to evacuate the air inside building and replace it with fresh air.”
Of the pollutants that can end up stuck inside airtight buildings, some are generated indoors, while others find their way in through cracks, open doors or windows, or even on the people going in and out. Some can come from both sources.
Man-Made Volatile Organic Compounds (VOCs)
Chemicals used in the manufacture of office equipment, furniture, wall and floor coverings and construction materials can off-gas into your interior environments. Cleaning products, pest control, copying and printing can also leave a variety of harmful compounds in the air. With extra cleaning measures in place due to COVID-19 concerns, and more products being sprayed on more surfaces more often, ventilation to move that particulate matter out is even more crucial.
Bacteria, viruses, fungi and molds can all travel through the air, causing illness, infection and fungal or mold growth.
Whether from idling vehicles, machinery, tobacco smoke, heating or cooking, combustion-related compounds such as carbon monoxide are among the most dangerous interior pollutants. High levels of carbon monoxide from a vehicle left idling in a garage can be lethal in a matter of minutes. Worse still, it’s odorless, tasteless and colorless – virtually imperceptible without a carbon monoxide detector.
Fine particulate matter
This is the “dust” you can see floating in a ray of sunlight and can be made up of any of the above as well as other fine particulate matter.
Pollutants can be generated by the most innocuous seeming sources, such as housekeeping or printers, but are caused more precipitously by renovation, remodeling or applying new paint or finishes.
Poor indoor air quality can result in serious health effects. These can range from mild and irritating to life-threatening. Eye, nose and throat irritation are common, as well as headaches, dizziness and fatigue. At the more severe end of the spectrum, poor air quality can trigger asthma attacks, and more hazardous pollutants like radon or carbon monoxide can cause cancer or be lethal.
Sick Building Syndrome
When poor ventilation and indoor pollutants combine, they can lead to what’s known as “sick building syndrome.” Many occupants experience similar symptoms after entering in “sick” buildings, and their symptoms tend to resolve after leaving. Air quality this poor has been blamed for everything from sub-par student performance to reduced productivity in occupational settings.
A Matter Of Opinion
Perception of poor air quality is important as well. Though these considerations are more subjective, they can still affect how employees, visitors and customers feel inside your building. Odors and temperature are two of the strongest variables affecting perceived air quality, as well as air movement. Too little feels stuffy, but too much can feel drafty and uncomfortable.
Air Exchange Basics
According to the EPA, “The air exchange rate is affected by the design, construction, and operating parameters of buildings and is ultimately a function of infiltration, natural ventilation and mechanical ventilation.” These all play a part in how much air needs to be exchanged or moved per minute, which is expressed in cubic feet per minute, or CFM. The more overall air exchanges per hour – including a measure of exchange with outside air – the better. However, the following factors and considerations contribute to what is required to manage and improve a building’s air quality and ventilation:
The size of a building determines how much air is inside it, and therefore is an important part of the necessary CFM calculation.
Buildings with fewer or no people, such as barns or warehouses, require much less ventilation – fewer CFM – than buildings with higher occupancy, such as a school, office building or church.
3. Number and Type of Openings
These can be intentional openings such as doors, windows and loading docks, as well as a building’s unintended openings which compromise its overall tightness, such as cracks and broken seals. External pollutants infiltrate a building through such openings, then the building’s tightness keeps them in.
4. Type of Airflow
Unoccupied buildings may only have natural ventilation, while livestock buildings or storage buildings might use industrial fans, and buildings designed for people are equipped with complete HVAC systems.
5. External temperature changes
Outdoor temperature changes – both day/night cycle and seasonal changes – dictate what level of insulation is ideal.
6. Insulation Type and Quality
As discussed, insulation is good for energy efficiency but makes integration of fresh air a challenge.
The absolute best way to ensure healthy air quality is to plan ahead and integrate adequate ventilation in your project from the very start. As Tjong points out, “Indoor air quality is the responsibility of HVAC engineers,” and they will be best enabled to provide that quality when their needs and input are included throughout the design process. Simply include HVAC engineers when you work with your Ceco representative. This way, fenestrations and other necessary roof and penetrations are planned for, as well as structural support for HVAC systems.
What You Can Do
We understand that while not everyone is in the midst of a new construction design project, everyone could benefit from better air quality. Simply being aware of everything discussed so far will help you rectify any existing problems – and prevent future ones – while following these simple tips will help even more:
- Get healthy, fresh air into the building when possible.
- Establish an effective smoking policy that protects nonsmokers from secondhand smoke.
- Ensure your HVAC system’s HEPA filtration is changed as directed.
- Be careful not to place furniture or other obstacles in front of air vents, grilles or intakes.
- Water and maintain office plants properly to avoid extra moisture – and therefore the development of mold.
- Dispose of garbage promptly and properly.
- Pre- and post-occupancy flushing, with exterior air is recommended if your system is capable of it.
- Be mindful of the unintended consequences of excessive cleaning product usage.
Also, be wary of unsubstantiated claims of many air “purifiers” on the market that claim to kill COVID-19 or purify the air through unproven means. At best, these will be an expense that accomplishes nothing. At worst, they can exacerbate indoor pollutants. For instance, ionizers generate ozone. This is unhealthy on its own, but it’s also highly reactive and can combine with other airborne substances to create harmful VOCs like formaldehyde and acrolein.
There are steps everyone can take to improve air quality and incrementally improve the health of both buildings and the people who live, work, shop and play inside them. To learn more about how Ceco can assist in designing a custom metal building with the latest in air quality features, reach out to your Ceco representative today.
According to the EPA, on average, Americans spend upwards of 90% of their time indoors. Between work, school, shopping and relaxing at home, the vast majority of our time is spent…