Houses Equipped With Humidifiers-What To Know | Ravinia HVAC
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Humidifier Operation

Humidifier Operation

Is Your Home Equipped With A Humidifier?

Many customers are under the impression that because a home is equipped with a humidifier, the home should always be humid. There are several factors that limit the operation of the humidifier and the amount of moisture that will be placed into the home.

  1. Most humidifiers have a humidistat that senses the current humidity and turns the humidifier on and off depending on the humidistat setting. The humidistat must be set to a position where the humidifier is running. A setting of 15 on the humidistat signifies 15% relative humidity or dryer air whereas a setting of 45 denotes 45% relative humidity or moister air. The setting must be changed with changes in the outdoor air temperature. The humidistat is typically installed on a furnace duct, usually close to the humidifier.
  2. A humidifier can only put moisture into the air when the furnace fan is running. Most thermostats have a fan switch that can be set to either “Auto” or “Manual” (sometimes labeled “ON”). The “Auto” setting will only run the fan when the furnace is on and heating the house whereas the “Manual” or “ON” setting will keep the fan running constantly. Therefore, to place the most moisture into the air, the thermostat fan switch should be set to “Manual” or “ON.” Unfortunately some newer furnaces will only humidify when the furnace is heating.
  3. The outdoor temperature has the greatest effect on how much moisture theair will hold. Warm air will hold much more water than cold air. The amount of moisture the air in the home can hold is determined by the coldest surface in the home, typically the windows. Because the surface of a glass window is much colder than the surrounding air in the home, you can only humidify to the “Dew Point” temperature, or the temperature at which the moisture in the air condenses on the window surfaces.
  4. Please be aware that when our technician leaves, the humidifier is checked for proper operation. If you believe the humidifier is not working properly and a problem is confirmed by our technician within the warranty period, there will be no charge for any repairs or adjustments. If however our technician finds nothing wrong with the unit or the warranty period has expired, there will be a charge for our services.

We realize that the science behind humidification, called psychrometrics, can be difficult to understand. If you have any questions regarding your humidifier or psychrometrics, please call us at (847) 432-5561 or email at [email protected] and we will be happy to answer your questions.

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Ravinia Plumbing, Sewer, Heating & Electric
575 Bond St,
Lincolnshire, IL 60069
P: (847) 579-5565
F: (847) 831-5694
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