Building Performance Toolkit
Indoor Air Quality
Photo credit: Lawrence Berkeley National Laboratory
For a building to be high-performing, it must have a satisfactory indoor air quality.
Sealing a building
If a building is well-sealed, energy costs will decrease because there will not be unnecessary ventilation or heating. A well-sealed building will have no cracks or gaps around windows, doors or floorboards. Heating, ventilation and air conditioning (HVAC) systems in a well-sealed building will have no leaks.
With a well-sealed building, the quality of the air sealed inside is important because it affects the building's inhabitants. Building owners will save money if IAQ is high. It is important to ensure high air quality at the start of new construction or renovation. Fixing worsening problems later in the building's life span will be more costly.
A building owner will also save money because IAQ directly affects worker productivity. Pollutants and contaminants have been shown to cause sick days, exhaustion and poor emotional and mental health. (More about IAQ and productivity.)
There are many factors which can contribute to IAQ. (More about problem sources and contaminants.) Many potential hazards have simple solutions if rapid action is taken. For existing buildings, IAQ can be addressed at any time, but should particularly be considered at the start of renovations.
Exhaust
- Exhaust from machinery and vehicles should not enter indoor spaces. This requires sealing a building to prevent the inadvertent infiltration of polluted outdoor air. Outdoor air pollution is a serious factor in New York City and other large cities. Building owners are required to meet New York's minimum requirement for the intake of outside air, 15 cubic feet per minute per person. To guarantee the quality of the incoming air, owners should use proper air filters. However, even air filters cannot eliminate all airborne pollutants, so it is important to aim for high intake quality even before filtering. While ventilation is required, it is not a complete solution for IAQ problems. Ventilating instead of addressing IAQ issues will lead to increased energy costs.
- Exhaust leaving indoor spaces should not be able to reenter the spaces. This requires checking that vents are operational and that exhaust vents are properly placed in relation to intake vents. Smoking areas around buildings should have exhaust-only systems and should not be placed near entryways or open-able windows. Where a gas water heater is used, a direct exhaust should be attached to the heater. Unvented machinery creates a risk of carbon monoxide poisoning for building residents. (More about carbon monoxide.)
Air filters
When ventilating buildings, fresh, clean outdoor air is ideal. However, in many cities, clean source air is not obtainable. Therefore, air filters are necessary. In general, there are two types of air pollutants: particles and combustion byproducts.
- For unwanted airborne particles, owners can install either or both of the following:
Mechanical air filters: particles are captured by physical filter trays and sheets.
Electronic air filters: particles are captured by generated electrostatic forces. - For unwanted combustion byproducts, owners can install gas-phase air filters. These usually target specific byproducts such as vehicles exhaust, cleaning fluid fumes, and paint. Gas filters are useful in cities because intake vents often cannot be removed from loading docks and heavy-traffic streets. Some byproducts such as carbon monoxide cannot easily be absorbed by filters and require specific approaches. Owners must install proper ventilation and sensors to avoid carbon monoxide accumulation.
The EPA has a brief guide about air cleaners as well as a more extensive guide to air cleaning options.
The U.S. Consumer Product Safety Commission has a guide to indoor air quality and remedies for issues.
Mold
Mold is primarily found in high-moisture areas and can have serious health effects. It is likely to surface in renovations, especially if walls or ceiling panels are removed and replaced. When encountering mold in renovation, the contaminated area should be sealed off, and an exhaust system should be installed. In addition to using a temporary exhaust system during renovation, building owners may consider adding or improving a permanent ventilation system to the renovated space. If mold is found in a certain space, the space likely has inadequate moisture or particle control. (More about mold.)
In commercial spaces, bathrooms are the most likely source of moisture. If a building contains kitchen or shower facilities, those areas should also be assessed for proper ventilation. In many situations, bathroom ventilation can be as simple as installing a window fan.
Pollutants and particles
- Pollutants can be introduced through several materials in the renovation process.
- Paint and cleaning chemicals are frequently used in building upgrades.
- In New York, pest control often requires the indoor use of pesticides.
- When painting and cleaning, owners should use proper ventilation and exhausts. Some paints, paint strippers, glues, cleaning supplies and pesticides contain Volatile Organic Compounds. VOCs should be avoided when possible, as they can cause illnesses including respiratory infections and cancer.
Pollutants stored in indoor spaces should be tightly covered. If possible, containers should be kept in sealed and vented spaces.
Cheaper materials are often more likely to contain harmful particles. Materials introduced into a building environment during renovation should be inspected for quality and content. When possible, used material should be avoided.
A larger version of the above image can be found at Allergy Free Air.
