Air that's too moist can create problems in the home environment. In addition to personal comfort, things like electronics, pianos, cameras, books and clothing can also suffer from excess moisture. Mold, dripping pipes, peeling wallpaper, warping wood, blistering paint and a pervasive musty smell are all byproducts of high humidity in the home. To maintain the ideal 40% to 50% humidity, a dehumidifier is the machine to own.
How Dehumidifiers Work
- Air is fan-forced over cool coils to remove moisture.
- The condensed moisture drips from the coils into a container.
- The drier air leaves through the back of the unit.
If you have air conditioning (AC), a dehumidifier shouldn't be necessary. If you're planning to purchase both, try the AC first and see if that solves the problem. If that doesn't work, or there are rooms, such as basements and laundry rooms, where air conditioning may not reach, it's time to shop for the proper dehumidifier. Dehumidifiers are rated according to their capacity: the number of pints of water removed during a 24-hour period. Units with 25-, 40-, 50- and 60-pint capacities are available. If you wish to be really scientific, get a humidity gauge to measure the relative humidity (the percent of water vapor in the air in relation to the amount it can hold at a given temperature) in the house. Or use the following chart to calculate the square footage of area to be dehumidified.
Values in the table indicate dehumidification required in pints per 24 hours, based on the area of the space to be dehumidified and the conditions that would exist in that space when a dehumidifier isn't in use. | |||||
| Air comfort level of the living space before dehumidifying during warm and humid outdoor conditions | Area—Square Feet | ||||
500 | 1,000 | 1,500 | 2,000 | 2,500 | |
Moderately Damp: Space feels damp and has musty odor only in humid weather. | 10 | 14 | 18 | 22 | 26 |
Very Damp: Space always feels damp and has musty odor. Damp spots show on walls and floor. | 12 | 17 | 22 | 27 | 32 |
Wet: Space feels and smells wet. Walls or floor sweat or seepage is present. | 14 | 20 | 26 | 32 | 38 |
Extremely Wet: Laundry drying, wet floor, high load conditions. | 16 | 23 | 30 | 37 | 44 |
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Needs vary by temperature and humidity level. If you're in doubt, buy the next larger size.
Dehumidifier Features
- Auto-Off: Senses moisture level and turns the unit on and off accordingly and saves energy
- Shut-Off: Shuts the unit off when the container is full
- Signal Light: Tells you the container is full
- Hose Attachment: Connects the tank to a floor drain. Normally a section of regular garden hose works
- Wheels: Allow mobility
How to Use a Dehumidifier
When you turn the dehumidifier on for the first time, set it to the driest setting possible to stabilize the room's humidity. After a couple of cycles, set the unit's automatic humidistat to the setting you need.
- Run the machine only when the room temperature is at or above 70°F.
- Keep doors and windows closed to prevent air loss.
- Maintain an unrestricted airflow. Keep at least 6 inches away from walls and furniture.
- Keep the coils clean.
- Keep the bucket clean.
- Look for frost on the coils. If frost collects on the coil, the air temperature is too cool to operate the machine. Frost keeps the machine from working properly. Turn the unit off and restart when it thaws or when the air temperature gets above 70°F.
- Help reduce humidity in your home by making sure gutters and downspouts are clean and dryer vents and exhaust fans are working properly.
- Plug the dehumidifier into an appropriate ground fault circuit interrupter (GFCI) outlet. Never remove the third prong from any plug.
- Always unplug the unit before cleaning.
- To avoid possible electric shock, unplug the machine when emptying the container.
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