For many homeowners, controlling their humidifier can be a frustrating experience. They must check the outside temperature in order to adjust the humidifier’s output of moisture. Too much moisture will cause condensation on windows and too little will cause health and skin irritations. For the most part, individuals have difficulty maintaining the appropriate 35-50% relative humidity (rh). In turn, contractors and technicians receive more callbacks to adjust or explain the workings of the humidifier.

With new humidification technology, these frustrations can be reduced. Currently, at least two manufacturers have made available a line of automatic humidifiers. These units do their own calculations and adjust the level of humidity and moisture accordingly.

The Choices

Research Products has developed the AprilAire Automatic Humidifier. According to Bruce Darkow, product manager for Re-search Products, the company first developed the technology 15 years ago. In fact, its automatic humidifier is in its second generation.

Research Products says its automatic humidifier is one of the first to be computer-equipped. The AprilAire model works by measuring indoor rh and the outside temperature. A temperature sensor is connected to the humidifier and is then run outside by a wire and attached to the house. The sensor will read the outdoor temperature over 86,000 times a day. With each outdoor reading, the humidity level will be adjusted according to the change in indoor rh and the change in outdoor temperature.

“The biggest benefit is 50% more moisture,” Darkow said about the product.

The AprilAire model is constantly measuring the changes in temperature and rh. This allows the humidifier to supply the maximum amount of humidity without causing condensation on windows.

Honeywell is another manufacturer offering a line of automatic humidifiers. The Honeywell models are similar to the Research Products line, but differ in the way they are controlled.

The first model is the H1008 Automatic Humidity Control, which has Honeywell’s patented HumidCalc+™ software.

According to the manufacturer, the installed software makes it possible for the humidifier to run without an outdoor sensor. All together, the H1008 has three sensors. One sensor reads the furnace run time, which allows the humidifier to estimate the outdoor temperature. The other two sensors will measure the indoor temperature and the dewpoint.

According to Tim Kensok of Honeywell’s Indoor Air Quality Division, by measuring dewpoint, the humidistat can accurately record the absolute amount of moisture in the air. Rh can change, but dewpoint stays the same.

Honeywell’s other model is the Perfect Climate Comfort Center™ Control system. According to Kensok, the Comfort Center works like the H1008 Model humidistat, but it takes all hvac units into consideration. This device not only automatically controls the humidifier, but also allows homeowners to control their air conditioning, ventilation, and furnace.

Industry Opinion

Automatic humidifiers are catching on with the industry.

Pat Mallon, general manager of All Season’s Heating & Air Conditioning in Toledo, OH, said that his business carries the AprileAire line, and is only installing automatic humidifiers.

Some dealers have not completely crossed over to the automatic model. Dennis Kline of Royal Oak Heating in Royal Oak, MI, also installs some AprilAire automatic humidifiers, but he feels that most of the industry has not caught on to the technology.

“The majority of dealers are staying away from them,” Kline said. “New technology just takes a while for them to get into.”

But Kline also feels that sooner or later automatic humidifiers are going to be the way to go when customers realize the alternative to the manual humidifier.

“People want less and less to do all the time and it is going to have to go to this point. People want as little to do as possible,” Kline said.

Mark Sims, president of the Suburban Air Conditioning Co. in Minneapolis, MN, represents Honeywell, and he also says that his company no longer installs manual humidifiers.

Sims agrees with Kline and says that customers “like simplicity and a lack of involvement with a product.”

So far, Sims says that the amount of complaints and callbacks on the automatic humidifiers have been very rare. For the Honeywell model, he says there have been no complaints. Sims has only had to help customers get through the initial adoption phase of the product, which he says happens with any new product.

Sims supplies both the AprilAire and Honeywell automatic humidifier, but installs more of the Honeywell line.

“The humidifier function and product are the same, and both are good products, but I believe dewpoint is more accurate than relative humidity,” Sims said.

Although Sims prefers the Honeywell model, he says that most customers would not know the difference between the Honey-well and the AprilAire model.

Publication date: 09/04/2000