Education: Humidification

As winter sets in, a heating system can begin to dry out the air inside a home. As the air becomes dryer, it can become less comfortable - throats, eyes and nose can become irritated. In prolonged dry conditions, woodwork and furniture can begin to crack and shrink. We all know how irritating it is to be zapped by static electricity. And if you own a computer, a static charge can damage both hardware and software.

Even if a home is tightly built, it can lose humidity. Extremely dry, cold outside air can quickly drop indoor relative humidity by 10 or 20% (cold winter air does not hold much moisture). Prolonged periods of dryness where outside structure can begin to dry and shrink framing, increasing gaps where outside air can infiltrate the walls causing drafts and higher energy consumption.

A properly sized and installed whole-house humidifier can easily correct all of these problems, maintaining a comfortable, healthy humidity level throughout the home. The normal humidity range for human comfort is between 35 and 45% Relative Humidity (RH).

It's important to choose the type of humidifier carefully. For example, studies show that standing water can promote bacteria growth. Better humidifiers are equipped with a drain that removes unused water from within the humidifier either continuously, or when it is turned off. These humidifiers fall into one of two categories:

• Power or Direct Humidifier
• Bypass Humidifier

Each type has advantages and disadvantages, and each is a better choice for certain applications.

The Power Humidifier has a built-in fan which pulls heated air directly from the hot air (supply) side of the furnace, pushes it across a water panel or media where the warm air picks up humidity, and flows back into the supply duct. The humidified air blends with the air exiting the furnace and is distributed throughout the home.

A Bypass Humidifier usually has no fan. It bypasses a portion of the forced air from the supply side of the furnace, forcing it across a water panel or media. The humidified air is then routed to the return side of the furnace, blending with air from the cold air return. The pre-humidified air is then heated by the furnace and delivered to the conditioned space.Both types of humidifiers are capable of providing the right amount of humidity. Your contractor / dealer can recommend which on is the best suited for your home