Have questions about AprilAire Whole-House Humidifiers? These are some of the most common inquiries we receive, but if you require additional assistance or information about the best humidifier, please contact our talented and knowledgeable customer support team!

How do I know which AprilAire Whole-House Humidifier I have on my furnace?

A photo that represents the look of your AprilAire Whole-House Humidifier can be found in your owner’s manual.

What is a water panel?

A water panel is the replaceable, evaporative element in an AprilAire Whole-House Humidifier that facilitates the conversion of water to vapor. AprilAire offers two types of water panels: Metal mesh and wicking depending on your unit.

Our metal mesh water panel is made of layered, slit-and-expanded aluminum with a porous, ceramic-type slip coating that absorbs water and maintains the proper level of hydration for the evaporation process.

Our wicking water panel uses a heavy-duty paper panel and is coated with an anti-microbial agent to prevent mold growth. It is reinforced with two layers of aluminum mesh so as air passes through the panel, moisture is absorbed and carried into the home.

AprilAire Water Panels 10, 12, and 35 should be replaced once per heating season and the AprilAire Water Panel 45 should be replaced twice per heating season.

How much water does an AprilAire Whole-House Humidifier use per day when humidifying?

The output of an AprilAire Whole-House Humidifier and water usage is affected by the run time of the furnace, the setpoint of the humidistat, and the home’s ability to hold humidity.

The AprilAire Model 300 Humidifier has a six gallon-per-hour feed rate.

AprilAire 400, 500, 600, and 700 Humidifiers have a three gallon-per-hour feed rate.

During normal usage, the Models 500, 600, and 700 typically use 1–2 gallons of water per hour. For these units, hot water can help boost the output but is required for the Model 700 as a heat source when mounted on the return air duct.

The 800 Steam Humidifier has an 11.5 gallon-per-hour feed rate. Customers typically see water usage between 1–3 gallons per hour. The voltage level supplied to the AprilAire Whole-House Humidifier will determine how quickly the canister heats the water to boiling—the higher the voltage, the fast the water heats up in the canister. This unit requires cold water to temper the hot water coming out of the humidifier’s drain when completing its weekly canister drain cycle.

What is the evaporation rate of an AprilAire Humidifier?

The Model 400 evaporates 100% of the water supplied to the humidifier and uses about 0.7 gallons of water per hour.

The Model 500 has a 0.5-gallon-per-hour evaporation rate.

The Model 600 has a 0.7-gallon-per-hour evaporation rate.

The Model 700 has a 0.75-gallon-per-hour evaporation rate when mounted on the supply side of the furnace and a 0.5-gallon-per-hour evaporation rate when mounted on the return air duct

The Model 720 has 0.88-gallon-per-hour evaporation rate on high speed and 0.79-gallon-per-hour evaporation rate on low speed.

Will a Model 500 adequately humidify a 3,000-square-foot home? What about the Model 600 or 700 for 4,000 square feet?

The AprilAire 500 Humidifier can add up to about 11 gallons of humidity to your home daily, which is usually good for homes up to 1,500 sq. ft.

The Model 600 and 700 each add up to 16–17 gallons of humidity daily, which is good for homes up to 3,000 sq. ft.

What model is best for tightly constructed large homes, up to 6,250 square feet?

The Model 720 Humidifier is the highest capacity AprilAire Evaporative Humidifier, delivering up to 21 gallons daily.

My contractor plumbs my Model 600 AprilAire Whole-House Humidifier with hot water. Is that how it should be installed?

To get the most out of AprilAire Whole-House Humidifiers, we recommend plumbing Models 360, 500, 600, 700, and 720 to hot water. We also advise using a standard hot water heater when plumbing hot water into your home. These units do not draw enough water to trigger tankless hot water heaters.

Why is the service light flashing on the AprilAire Steam Humidifier a week after changing the canister?

A flashing service light indicates that the sensed amperage is 75% of the maximum amperage recorded. The reason why it may be occurring is that the humidistat may not be giving the unit enough time to condition the canister.

If the hose is getting hot and the light is flashing, let the unit run, and the flashing light will eventually go away once the amp draw in the canister grows. If the hose is not getting hot, contact our customer support team for troubleshooting information.

How does the blower activation operate with the humidistat?

The blower activation switch is set to the “ON” position to allow your AprilAire Whole-House Humidifier control to activate the HVAC fan for maximum humidification. For this setting, be sure Model 500, 600, 700, and 720 units are connected to hot water.

If your system is idle for at least 1 hour, the humidifier control will activate the HVAC system fan for about three minutes to sample the air. If your humidity level reads lower than the setpoint, the humidifier control will activate your AprilAire Whole-House Humidifier and keep the fan running. It will continue operating for two hours or until the setpoint is reached.

If your setpoint has not been reached by the end of a call for heat, the control will continue to operate the AprilAire Whole-House Humidifier and the HVAC fan until the setpoint is reached or two hours have elapsed.

When the blower activation switch is in the “OFF” position, the control will only operate the humidifier if humidity is required and the HVAC system fan is operating, or the system is producing heat.

How accurate is the Model 60 and 62 Humidistat?

Our Model 60 and 62 Humidistats are tested to be within +/- 5% accuracy from the factory before being shipped.

Are there additional controls to operate AprilAire Whole-House Humidifiers?

The AprilAire 65 Digital Manual Humidistat and the 4655 Manual Humidistat can be mounted on the wall to control your Humidifier.

AprilAire Wi-Fi Programmable Thermostats, including the 8620W, 8910, 8910W, 8920W, and S86WMUPR, can control the unit in place of a Model 60 or 62 Humidistat.

Does UV light affect AprilAire Whole-House Humidifiers in any way?

It’s recommended that UV light installers direct the light away from plastics or protect them with something, like aluminum tape, which is UV-immune.

The plastic frame around the water panel, called a scale control insert, is made of a UV-resistant material but is not immune to the effects of UV light. The water panel is clay-coated aluminum, so it will not be impacted by UV light exposure.

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