Why Is Indoor Air Quality Important & How to Create It
Experts agree that controlling or conditioning indoor air is the best way for a business to increase employee efficiency and to reduce costs connected with employee health care. Fox Blocks ICF walls provide the tight exterior building envelope that is the first step in controlling the indoor air environment. Fox Blocks buildings have high steady state R-values, low air infiltration rates, and the solid concrete walls provide superior thermal mass. The healthiest, most energy efficient building is built "tight" with mechanical ventilation to ensure indoor air quality and moisture control. Opening a window and bringing in fresh outside air alone does not give good indoor air quality. Fresh air enters the building, but that air is not conditioned. It has moisture, dust pollen and mold particles that need to be controlled and conditioned.
Improving indoor air quality can increase profitability for businesses and building owners by increasing individual productivity, reducing employee or tenant turnover and disputes and reducing HVAC energy consumption and equipment repair.
The EPA lists indoor air quality as the greatest threat to people's health. Good indoor air quality is especially important for people with asthma and other allergies. The number of asthma patients has doubled in the United States within the last 10 years, but lowering the humidity and unfiltered air in buildings can help reduce the symptoms of asthma.
Dust mites. 90% of the people who have allergies are sensitive to dust mites. Cleaning duct systems and air filtration alone are not effective methods of treating for dust mites, because dust mites are also found in upholstery, carpets, and bedding. Since they require 55% humidity to survive, controlling the indoor humidity to a maximum of 50% is the best way of eliminating them.
Mold. Mold not only creates an unhealthy living environment—it also causes structural damage. People react to both the mold spores and the toxic gases released by the mold. Like dust mites, mold also requires higher humidity levels to survive, so controlling humidity can eliminate mold growth.
Create Quality and Healthy Indoor Air
Humidity control is the critical factor for healthy indoor air quality. The healthiest indoor air environment is 40% to 50% humidity with temperatures ranging from 68º to 70º F. Also, the American Society of Heating Refrigeration and Air-Conditioning Engineers (ASHRAE) recommends 0.35 air changes per hour. The most cost effective way of controlling indoor air quality is with a mechanical ventilation system. These come in three types:
- Exhaust Ventilation System - Stale air is drawn to a quiet vent and exhausted outdoors.
- Balanced Ventilation System - Exhausts stale air out and brings fresh air in from the outside. These systems are called air-to-air heat exchangers or heat recovery ventilators. The temperature of the outside air can be conditioned to within 95% of the indoor air temperature.
- Supply Ventilation System - Pressurizes the building, forcing the stale air out and controlling the humidity all within one system. It allows for treating the fresh air before introducing it to the indoor air. The treatment removes pollen, dust and mold spores from the outdoor air.
Conventional HVAC systems are not designed to control the humidity below 50%. With the removal of the moisture from the indoor air, the air conditioner is able to cool the air more efficiently, making the building more comfortable. Other ways of controlling indoor air quality include removing pets and pests, and eliminating smoking from the indoor environment.