Air Conditioning 101 (Part 3)

What Else Does An Air Conditioner Do?

The previous 2 posts of our Air Conditioning 101 series have focused on cooling because we live in such a warm climate, but remember that the original definition of air conditioning contains more than that: an ideal air conditioner should heat, cool, clean, ventilate, humidify and dehumidify as needed to provide health and comfort. In fact the second most important objective of the original definition is to provide ventilation.

Without adequate ventilation, contaminants generated indoors will can lead to significant health and comfort problems. Avis recommends that there be at least enough ventilation to exchange the air inside house once every four hours, depending on house design. Older homes tend to have leakier walls and leakier ducts and mostly get sufficient ventilation through such leakage. Such leakage and infiltration may not be the most energy efficient approach to ventilation and is an opportunity for savings. On the other hand, most new homes and some existing homes are relatively tight and thus require mechanical ventilation to meet minimum ventilation requirements. Avis can help you with that.

Is Humidity Really An Issue?

Yes! After all, humidity control was the problem that originally spurred the need for air conditioning. Lack of humidity control in hot, humid climates like Southwest Florida can lead to mold growth and other moisture-related problems. Because high indoor humidity can lead to health and comfort problems, having an air conditioning system that is working correctly to help with humidity is extremely important.

Modern air conditioners dehumidify as they cool — you can see that by the water that usually drains away somewhere outside of your house. This effect is completely incidental to their main job of controlling temperature, however — an added benefit, if you will. They rarely control both temperature and humidity independently.

In hot, humid climates the incidental dehumidification that occurs may not always be enough to keep the indoor humidity conditions acceptable. Ideally you want a 60% relative humidity maximum at 78F. The maximum dehumidification happens not at the hot times of the year—when the air conditioner is running a lot, but at mild times of the year when the air conditioner runs very little.

Although there are some leading edge air conditioning systems that independently control humidity, most conventional systems may not be able to sufficiently control the problem and can cause comfort or mold problems in certain situations. Some current high-end systems have enhanced dehumidification, but when the existing system cannot sufficiently dehumidify, it may be necessary to buy a dehumidifying unit. If you need help managing the humidity in your home or place of work, give Avis a call and find out what your options are.

What Can I Do To Help Control Humidity?

For starters, do not set your thermostat to the “fan on” position. In this position the fan blows air all the time whether your cooling system is running or not; one important effect of this is that a lot of the moisture your system just took out of the air will now be blown back into the house before it can drain away.

Use exhaust fans during moisture-producing activities. Cooking, bathing, washing, and similar activities produce a lot of moisture inside the home. Exhaust that moisture directly outdoors using a fan. Similarly, avoid drying clothes indoors except with a clothes dryer that is exhausted directly outdoors. Likewise, do not open windows when it is too humid outside.