As the emphasis continues on constructing more energy-efficient homes and buildings, engineers and scientists have developed various indoor air quality products to address the problems associated with poor indoor air conditions. Building an energy-efficient structure requires limiting the amount of outside air that enters the building’s envelope.
While tight structures do save energy, indoor air quality (IAQ) can suffer. The components of indoor air pollution include:
- Biological contaminants
- Unhealthy humidity levels
Particulates such as household dust, pollen and pet dander can cause allergic reactions and trigger asthma attacks. Gases can build up indoors including volatile organic compounds (VOCs), radon and carbon monoxide. Biological contaminants include mold spores, and airborne bacteria and viruses. Too low or high humidity levels also impact respiratory health.
The U.S. EPA reports that polluted indoor air is among the top five environmental hazards people face. Given the amount of time you spend inside, doing what you can to improve indoor air quality protects your health and well being.
Fortunately, indoor air quality products can reduce the levels of these harmful substances, which will improve comfort, human health and the health of your home. Filtering the air, ventilating with fresh air, eradicating harmful biological contaminants, and maintaining healthy humidity levels are all possible using today’s technology.
Airborne particulates pose problems for both you and your HVAC equipment, which is why all forced-air HVAC systems require an air filter. This filter traps particles each time the system runs. These filters carry MERV (minimum efficiency reporting value) ratings that indicate the smallest particle the filter can trap.
Residential filters are available with ratings from 1 to 16, and by using a filter with a higher MERV rating, you’ll remove more and smaller particulates from the air. However, before upgrading the filter, check the owner’s manual for your equipment to learn the highest value you can use. Denser filters slow the air flowing through the system, which can harm the equipment and degrade performance.
One of the best ways to ensure that your home’s air is as particulate-free as possible is to use filtration systems that connect to the HVAC equipment. These systems use denser filters and boost the airflow mechanically so that your cooling or heating system has the air pressure it needs.
The most effective filtration system uses HEPA (high efficiency particulate air) filters that trap 99.9 percent of particles as small as 0.3 microns. These are the same filtration systems used in surgical suites, clean rooms and laboratories. If anyone in your home suffers from airborne allergies or asthma, adding such a filtration system to your equipment will reduce their symptoms and discomfort.
Another approach is to use electrostatic filters inside the HVAC system. These use electricity to attract particles to a metal plate that needs to be cleaned periodically. HEPA filters need replacement at intervals, whose length depends on a variety of factors including how dirty your air is, and how much you’re running your cooling or heating system.
Indoor air quality products are available that provide adequate ventilation without lowering your home’s energy efficiency. Heat recovery ventilators (HRVs) and energy recovery ventilators (ERVs) exhaust some of the stale indoor air while bringing in the same amount of fresh air. They use technology that strips the outgoing air of its thermal energy and transfers it to the incoming air for heating (or vice versa during the cooling season). ERVs are particularly useful in our climate since they remove the humidity in the incoming air.
Ventilation dilutes the concentration of VOCs in the air that can cause minor to serious health problems. VOCs come from many common compounds found indoors, including household cleaners, fabrics, paint, carpet and dry cleaning. People react differently to VOCs, from minor irritations to major illnesses marked by nerve or liver damage.
While these ventilation systems dilute the concentration of VOCs, they should not be used in place of carbon monoxide detectors or safe use of any combustibles and combustion appliances in your home. They also may not be enough to dispel concentrated amounts of radon in your home, another odorless, colorless gas that degrades IAQ and is the second highest cause of lung cancer in the U.S.
Getting rid of mold spores and germs will help improve your IAQ, and it’s possible using either UV (ultraviolet) lights or indoor air quality products that combine filtration with UV lights. The ultraviolet spectrum of light alters the DNA of bacteria, viruses and mold spores, preventing them from reproducing.
UV lights have been used for nearly a century to eradicate harmful biological substances in medical settings, food processing and serving centers, and large public places. The lights are an effective way to eradicate the spread of infectious diseases and harmful molds.
UV lights usually are either placed in HVAC system ductwork or positioned to shine directly on the evaporator coil and/or condensate pan. These uses offer these benefits:
- Minimizing mold growth on the evaporator coil. The indoor coil carries the cold refrigerant that absorbs heat from your home. As the air cools flowing over the coil, the water vapor inside it condenses on the coil and it drains away. The coil provides a moist environment perfect for mold and bacterial growth. Besides the potential health problems associated with these organic growths, the coating of grime slows the ability of the refrigerant to remove heat from your home and drives up cooling costs.
- Stopping mold growth in the ductwork. Left alone, mold spores that enter the ductwork can grow and spread. Since ducts are hidden from view, unchecked mold growth can prompt the need for professional intervention.
- Limiting mold growth in your home. Mold’s role in nature is to break down organic materials. All it needs is warmth, food and moisture to thrive. It can grow on drywall, in furniture and carpets as mildew, and attack the wood from which your home is made.
- Attacking a wide variety of micro-organisms contained in your indoor air as the air passes through the ducts and is exposed repeatedly to the UV light rays.
Some indoor air quality products include UV lights as part of filtration systems. Not only do they trap offending particles, they will eradicate the viable bacteria, viruses and mold spores in your home’s air. Whether used in a stand-alone air cleaner or incorporated in a forced-air system, both uses of UV lights will need bulb replacement periodically to maintain their effectiveness.
Humidity levels have an impact on your health and that of your home. When they’re out of the healthy range, between 30 and 50 percent, they can cause discomfort, spread diseases and harm your home. Indoor air quality products for humidity management include humidifiers and dehumidifiers.
Both of these devices are available as portable devices or those that can be attached to your HVAC system for convenient whole-house management of humidity levels, whose benefits include:
- Reduced energy bills. High indoor humidity levels make your home seem warmer. If you find yourself turning the thermostat down just to lower the humidity level, a dehumidifier will increase your comfort without having to use your cooling system as much.
- Humidity levels over 50 percent create a welcoming environment for dust mites and mold growth, both of which are potential allergens and respiratory irritants. Mold and mildew can destroy the materials on which they grow. Dust-mite waste is a common respiratory irritant and allergen. A central dehumidifier drains into your home’s plumbing and controls humidity levels with a humidistat, similar to a thermostat.
- It’s no surprise that winter is called the cold and flu season. Dry air causes the moist coating around bacteria and viruses to evaporate quickly, enabling them to embed themselves in your respiratory tract faster. The dry air also leaves your nose and throat vulnerable, since lack of humidity also irritates them.
- Dry air causes skin problems as well, along with static electricity that can damage electronics. The wood products in your home can shrink and crack. A central humidifier is one of the best indoor air quality products to manage humidity levels in the winter, since the appliance works automatically to provide you with the most comfortable humidity level.
- A portable humidifier will only add moisture to the area where it’s located, needs constant refilling and weekly cleaning to keep bacteria from growing inside it. A central system delivers measured amounts of water vapor throughout your home, eliminating the problems dry air causes.
Since your home’s IAQ has a direct impact on your overall well-being, using effective indoor air quality products can go a long way toward improving health and comfort. To learn more, contact the pros at Griffith Energy Services, Inc. We’ve provided exceptional HVAC services for homeowners in the Baltimore and Mid-Atlantic area for more than 100 years.
Written by Kevin Spain.
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