Dehumidifier Repair & Humidifier Maintenance

Dehumidifier Repair & Humidifier Maintenance

Dehumidifier Repair & Humidifier Maintenance

Regulate moisture content in household air to prevent condensation damage and to increase comfort.


As the temperature drops, the ability of the air to hold moisture decreases. Therefore, in winter months the air becomes drier. Coupled with the dry heat produced from forced-air furnaces, the air inside a house can become too dry for comfort. To compensate for the lack of comfort, we need to turn our thermostats up to at least 24°C (75-F).

However, by adding a power humidifier to your furnace, you increase the moisture content of the air, and in so doing can decrease the thermostat setting and still maintain a comfortable level of heat.

Relative humidity, defined as the actual amount of water vapor in the air compared to the actual amount of water vapor the air can hold, should be between 30 and 45 percent. Power humidifiers allow you to set the humidity level for maximum comfort.

There are two different types of power humidifiers used in homes. The most popular is the evaporator type, which forces warm air through a stationary or moving wet pad where it picks up moisture and then goes back into the supply duct and out into the house. This type of humidifier is designed for homes with forced-air heating, but there are other types of evaporator humidifiers that come equipped with a blower fan that can be installed with different heating systems. With this type of humidifier, hot water evaporates and is circulated to a central grille in the house.

The second type of humidifier is the atomizer. It breaks water into fine particles which are then absorbed by the surrounding air. Because this type of humidifier can operate independently of the warm air in the furnace, it can be located almost anywhere in the house where water and electrical connections are convenient.

The evaporator type of humidifier is usually attached directly to the warm-air plenum of the furnace. A copper tube is attached to the nearby cold-water pipe, providing a constant supply of water to the humidifier. As water moves up from the water trough and into the wet pad, where t evaporates into the warm air, the float moves down, opening the valve to allow more water into the trough.

The inside of the unit has a tendency to become coated with mineral deposits from

the water When you shut the humidifier off for the summer, remove the wet pad and float from the unit and scrub them free of deposits. The wet pad can be soaked in a vinegar and water solution until it comes clean. Scrub the sides of the unit with sandcaper to eliminate the build-up. The humidifier will be in clean condition for winter operation.


While in the winter months some houses suffer from too little humidity, the summer months can bring too much moisture into the air. Even, in winter, frequent showers, drying clothes and cooking can contribute excessive amounts of moisture to the air. There are several methods of eliminating excess air moisture, including bathroom ventilation fans to force wet air outside, making sure your clothes drier is vented to the outside, a hood over the stove top with access to an outdoor vent, and dehumidifiers that remove moisture from the air and deposit it into buckets.

A fan in the dehumidifier draws wet air through the back of the unit and over refrigerated coils. The moisture condenses on the coils and drips into a bucket, while the dried air continues through the dehumidifier and out through the front into the room.

A humidistat control on the unit allows you to adjust for the amount of moisture you want removed from the air, and the unit turns off automatically when that level is reached.

Most dehumidifiers have a capacity for removal of 5 to 14L (10 to 30pt) of water, which is the amount of water removed from the air in a 24-hour period at 60 percent relative humidity and an air temperature of 26°C (80°F). A 14L (30pt) capacity unit would be enough to handle the demands for a basement, providing air moves freely through the basement.

When buying a dehumidifier, make sure the capacity can handle your needs. Also look for a unit that has a humidistat, so that you can preset a humidity level for comfort. The unit should also have a catch bucket for the condensation or a hose connection that attaches to the nearest drain for continuous removal of water. With the catch bucket, make sure the unit has an automatic overflow control that will shut off the dehumidifier when the bucket becomes full. Most units have a red signal light to indicate this.

Clean the filter at the back of the unit regularly, and keep dirt and dust from the air-drying coils.


In a dehumidifier, a motor and fan draw wet air through the back of the unit and over refrigerated coils. The moisture condenses and drops into a collection bucket. The dry air is then forced out the front of the unit.

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