Breathe Easy by Resolving Indoor Air Quality Issues
Air quality affects everyone who spends time inside buildings. Trying to solve problems with indoor air can lead to headaches for facility managers, building owners, and occupants alike. There are, in most cases, several simple things that can be done to improve the quality of indoor air.
The following list contains the fundamentals for both preventing and solving air quality problems (thank you to Terry Brennan of Camroden Associates for first articulating this list):
- Understand and educate people
- Keep the building dry and clean
- Provide thermal comfort
- Reduce potential contaminant sources
- Exhaust nasty stuff
- Reduce unplanned airflows
We start with people since they can change buildings from the way the design intended. People may block diffusers to avoid drafts, store chemicals where it is convenient rather than where designated and not know that it causes a problem. That is where the education piece comes in. Letting the building occupants know that there is a storage space for those smelly art supplies and it is exhausted to the outdoors to prevent people breathing in the smells may help to gain acceptance of policies.
Dry, clean buildings do not have mold and dust problems. Mold and dust can be allergens and asthma triggers so they lead to air quality complaints. Moisture control is mold control and effective cleaning is dust control.
Thermal comfort in this context means providing control of both temperature and humidity. People tend to perceive better air quality in buildings with good temperature control. Humidity is another word for moisture in air (water vapor). Part of keeping a building dry is maintaining the humidity below about 60%, so that cold surfaces will not condense water.
Contaminants in buildings can be things like cleaning chemicals, science room supplies, and even gases that are emitted from new furniture and carpet. When purchasing these types of materials it is best to choose the least toxic type that can still get the job done. When more smelly things need to be used, they should be stored in a way that gets the odors out of the building.
Many places in a typical building require exhaust to control the odors and contaminants listed above. These include bathrooms, janitor’s closets, any chemical storage spaces, and may even include the place where wet coats are stored. Since we are trying to keep our buildings dry, even water is a contaminant that we want to exhaust to the outside.
In general, we ventilate building for the occupants. By bringing in outdoor air and balancing that delivery with some exhaust, the concentrations of contaminants that can’t be isolated and exhausted individually can be controlled. Things like perfume and even the cat dander that is on your clothes can have its concentration in the air reduced by providing proper ventilation.
The last fundamental can often be the hardest to solve and may require expert help. Unplanned airflows in buildings occur whenever there are pressure differences. This includes air from a basement or crawlspace (along with its moisture and odors) getting into the occupied areas of the building. Unplanned air flow could also explain why the smell from the boiler room ends up three classrooms away.
Keeping these seven fundamentals in mind when thinking about air quality problems can go a long way towards solving or preventing the issue in the first place. For more information about air quality problems and resolutions check the Environmental Protection Agency website. For those in New England, coming up on April 11th and 12th, the Maine Indoor Air Quality Council has its annual conference where building experts will get together to delve deeper into the areas of indoor air quality and energy efficiency.
Posted by Maine Indoor Air Quality Council