Can Dehumidifiers Improve Indoor Air Quality?
Maintaining a proper humidity level is one of the most important steps in providing a comfortable and healthy home. Excess moisture in the home promotes harmful indoor air particles, including mold, bacteria, viruses, dust mites, allergic rhinitis and asthma. In addition, a home with excess moisture can be uncomfortable – regardless of the temperature.
Building codes and HVAC system designs have changed over the years, impacting IAQ in the home. Unfortunately, many of these well intended changes to create tighter, more efficient homes, have led to moisture problems, musty odors, and high levels of VOCs that need to be resolved. Ultra Aire Whole House Ventilating Dehumidifiers can eliminate these issues and work with your HVAC system to truly create a comfortable, efficient and healthy environment.
The purpose of ventilating a home is to maintain a healthy and safe living environment.
The reason for the buildup of indoor pollution in today’s homes is a direct result of our efforts to conserve energy and save money. As the techniques and materials used to insulate and seal our homes has improved, the result is stale and polluted air trapped inside.
Common sources of indoor airborne contaminants include:
- Chemicals used in the construction or renovation of buildings
- Appliances that burn gas
- Wood-burning stoves and fireplaces
- Off-gassing of furniture, cabinets, flooring, and countertops
- Infiltration of ozone, pollen, and molds from the outside
- Cleaning supplies
Air Quality + Exchanges
The rate at which outdoor air replaces indoor air is described as the air exchange rate. When there is little ventilation, natural or mechanical, the air exchange rate is low and pollutant levels can increase.
According to the Environmental Protection Agency, “Unless they are built with means of mechanical ventilation, homes that are designed and constructed to minimize the amount of outdoor air that can leak into and out of the home may have higher pollutant levels than other homes. However, because some weather conditions can drastically reduce the amount of outdoor air that enters a home, pollutants can build up even in homes that are normally considered leaky.”
What Is Dew Point?
Dew point is the temperature at which the moisture in the air begins to condense.
A common way to measure dew point is to start with Relative Humidity (RH), which is the ratio of the amount of moisture in the air at a specific temperature to the maximum amount that the air could hold at that temperature, expressed as a percentage.
Think about a cold soda can on a hot summer day. If the surface temperature of the can is 55°F and the dew point of the air is 60°F, condensation will form on the surface of the can.
What Is Relative Humidity?
Relative humidity (RH) is the amount of water vapor in the air, expressed as a percentage of the maximum amount of water that the air can hold at a given temperature.
Due to temperature variations, RH can vary dramatically. In fact, it is not uncommon to find summertime RH levels ranging from 50% to 100% in the same home. Warmer air holds more water than cooler air and for every one degree change in temperature, the RH changes by about 2%.
Let’s assume you live in a house with a basement. If the main floor is 77°, the basement temperature may only be 67°. Even though there is only a 10° temperature difference, there is a 21% difference in RH. Because the basement temperature is closer to the 62° dew point, it will likely feel damp as well.
Homes built on a slab have a similar problem. Though the room temperature may be 77°, the temperature on the slab is much cooler. As the slab temperature approaches the dew point temperature, RH rises and condensation can form. When this occurs, mold, mildew, and other biological growth soon follows.
Other symptoms of high humidity include:
- Musty odors
- Allergic reactions to mold or dust mites
- Cupped wood floors
- Feeling sticky or clammy
- Visible condensation or water stains
- Peeling wallpaper or blistering paint
What Is an Ideal Home RH?
The EPA recommends an ideal relative humidity between 35% – 50%. In order to maintain this level, a specialized high capacity dehumidifier is typically required as most air conditioners and conventional dehumidifiers are not designed to consistently achieve dew points low enough to avoid condensation or high RH levels. Ultra Aire Whole House Ventilating Dehumidifiers are unique in their ability to effectively and efficiently remove large quantities of water from your entire home, creating a more comfortable and healthier environment.