Air Quality

Your heating, ventilation, and air conditioning (HVAC) system can do more than heat and cool your home. It can also keep the humidity at a comfortable level in winter and summer. It’s a delicate balance: if it’s too low, you’ll feel the effects of colds, respiratory infections, and asthma more, and some of the furnishings in your home will literally dry out. If it’s too high, you’ll be uncomfortable but mold and mildew will flourish. They love moisture!

Residential HVAC systems balance temperature and humidity. The best person to design a system appropriate for your climate and your comfort needs is a professional ACCA member contractor. He or she understands the science of your home and applies the principles contained in the ACCA design and technical manuals to the design, selection, and installation of an HVAC system that’s right for you.

ACCA manuals are the industry standard, often incorporated into local building codes and endorsed or recommended by the Department of Energy, the Environmental Protection Agency, and equipment manufacturers.

Relatively Speaking …
Relative humidity (RH) is the percent of moisture actually in the air compared to the maximum amount of moisture the air can hold at that temperature. Cold air can hold less moisture than warm air. At 70ºF, air can hold as much as 12 times the amount of moisture as 10ºF air. That’s why it’s usually more humid in the hot summer months.

Winter Humidification
Most heating systems just heat the air, changing the temperature, not the humidity. Cold air is dry, and forced-air systems and heat pumps pull outside air for heating. When 10°F outside air is heated to 70°F, the humidity level in your home will be the same as the outside air’s, around 7%. That’s […]

There’s Good Mold and There’s Bad Mold

Molds are the “bleu” in bleu cheese and Roquefort. Molds improve our wine. They produce penicillin and antibiotics and are used widely in the food and beverage industry. Without mold and mold’s decaying mechanism, the natural environment would be overwhelmed with large amounts of dead organic matter.

Despite many harmless and beneficial molds, some molds can be toxic and pose health threats to humans. The Environmental Protection Agency (EPA) cautions that all molds can cause health problems under the right conditions. The word “toxic” refers to mold that produces hazardous compounds, or mycotoxins.

Often included in the list of toxic molds is Stachybotrys Chartarum, a greenish-black mold, which can grow on high-cellulose, low-nitrogen materials such as fiberboard, drywall, paper, dust, and lint – all of which are found in homes – when these materials become wet.

There is evidence that mold exposure can cause the following symptoms:

Allergic reactions, including irritation of the eyes, nose, or throat.
Flu-like symptoms, including fatigue, dizziness, headaches, and diarrhea.
Worsening of asthma.

How to Minimize Mold Growth
Mold is a natural byproduct of the fungi family that thrives when organic substances and water combine under certain circumstances. Mold reproduces via spores that can remain dormant, yet viable, for years. They “come alive” again in the presence of moisture.

HVACR mechanical systems are not generators of mold; their metallic surfaces do not provide the organic matter mold needs to grow. However, systems that are not well maintained could support mold growth. It’s important that your system:

Is designed and installed correctly.
Is properly and regularly maintained.
Controls the moisture in your building.
Uses good filtration methods to keep your air clean.

Preventing Mold

Consider augmenting your air conditioner with a dehumidifier. These systems pull the moisture from the […]