4 FM quick reads on IAQ
1. The IAQ-Sustainability Connection
I'm Dan Hounsell, editor of Maintenance Solutions magazine. Today's topic is, IAQ and sustainability.
Chemical toxins lurk everywhere in institutional and commercial buildings. These substances can cause cancer, contribute to respiratory illness and failure, and lead to birth defects. They also can affect the quality of our lives, as well as those of future generations.
The sustainability movement within facilities addresses these issues head-on by encouraging the specification of building materials with few or no volatile organic compounds, or VOCs, proper procedures during construction and retrofits to protect indoor air quality, and the elimination of chemical products, says Rasika Savkar, technical consultant at Building Insights, an LLC of Green Building Services Inc., in Portland, Ore.
Unfortunately, IAQ has not risen much on the priority lists of many maintenance and engineering managers. Managers who don't educate themselves and remain vigilant on IAQ are unknowingly undermining occupant health.
If managers think the U.S. Environmental Protection Agency (EPA) is an IAQ fail-safe, think again. While the EPA is supposed to track the toxicity of materials, it wasn't founded until the 1970s, and chances are, at least some buildings in any given organization are older than that.
Materials that went into walls, insulation, ductwork and mechanical systems for decades might have contained chemical compounds that weren't on the list as causing cancer or asthma. As a result, many chemicals are in the DNA of buildings. If you care about the serious health risks your facility might pose to occupants and visitors, bring in an expert to conduct a thorough materials audit.
Unfortunately, Savkar says, awareness of compounds contained in facility materials and components has not increased in proportion to the rate of their invention. As a result, these chemicals make it into facilities before they have been properly tested.
What can managers do? Make decisions about the chemicals they allow in their facilities because many of these toxins remain inside the building. The best defense is knowledge.
Demand Control Ventilation Can Reduce Energy Costs
Today's tip from Building Operating Management comes from Angela Cremeans and R. Stephen Spinazzola of RTKL: In spaces that have widely varying levels of occupancy, demand control ventilation can reduce energy use and costs.
Many spaces are unoccupied for significant stretches of time, including churches, auditoriums, offices and retail spaces. Despite that fact, most HVAC systems are designed to bring in the same level of outside air continuously. But if a space is unoccupied, heating, cooling and moving outside air to that space can waste a significant amount of energy and money.
Demand control ventilation is a sophisticated strategy that supplies outside air to a space only when it is needed. Demand control ventilation relies on the fact that people in a space produce carbon dioxide. Sensors measure carbon dioxide levels. As those levels rise, more outside air is brought into that space. If levels fall, the amount of outside air is reduced, cutting the cost of conditioning and moving outside air. The amount of air is tailored to the specific needs of a given zone.
In a demand control ventilation strategy, the level of carbon dioxide is taken as a general indicator of the level of other contaminants. By increasing the amount of outdoor air brought into a space when carbon dioxide levels rise, the concentration of those other contaminants is reduced, improving indoor air quality.
Demand control ventilation can save energy costs in three ways:
1. Less outdoor air has to be conditioned by the HVAC system, so heating or cooling system energy is saved.
2. Less air has to be moved, so fan energy is saved.
3. If a building has a heat recovery system using building exhaust, that can further reduce the amount of energy consumed.
Using ASHRAE 62.1 to Maintain Good IAQ
Facility managers can use ASHRAE 62.1's recommended ventilation rates to get an idea of whether the rates in their buildings are too high (and therefore not energy efficient) or too low (and therefore not conducive to good indoor air quality).
Now, no one will likely check whether a building is in ongoing compliance with ASHRAE 62.1 on an outside airflow basis, but if there's ever a problem, it's going to look bad if you don't know whether you're in compliance or not. It's good risk management best practice to have the data available.
Another aspect of compliance with 62.1 is preventive maintenance, which also fosters good indoor air quality. If you're measuring the percentage of prescribed preventive maintenance being completed, based on the maintenance manual that ASHRAE 62.1 requires must be provided when the building is handed over, a high percentage of completed preventive maintenance points to likely good indoor air quality. It means you're regularly checking filters, regularly examining dampers to make sure they're opening and closing properly, and making sure drain pans aren't full of water.
ASHRAE 62.1 also provides a standard (maximum of 65 percent in the 2007 edition) for relative humidity, which also plays into indoor air quality. Air that is too wet promotes mold growth. But air that is too dry (especially in the winter) can be just as bad for indoor air quality, causing occupant's mucous membranes to dry out and making them uncomfortable.
Measuring the dew point temperature and humidity, and benchmarking that data, is one of the more important, yet overlooked, parts of maintaining good indoor air quality.