Dehumidifiers for Basements

Find the Best Dehumidifier for your Basement

1. Low Temperature Operation. A low temperature or basement dehumidifier is designed to be able to operate at temperatures below 65 degrees. If the temperature drops below 65 degrees, the water can freeze on the evaporator coils in the dehumidifier and the continued build-up of ice could result in interference with the air-flow and possibly fan motor burnout. A low temperature dehumidifier will prevent ice build-up by using an intermittent defrost cycle, which will shut the compressor off when the coils become too cold. Once the coils warm up a bit, the compressor can resume dehumidifying. Please note that while the industry standard is 65 degrees, we recommend purchasing a dehumidifier which will operate at quite a bit lower. Even if you have a so called 'low temperature' dehumidifier, while it may not ice up, it may not be able to bring the humidity down to desired levels because of the strong correlation between temperature and a dehumidifier’s ability to remove water. The lower the room temperature, the harder it is to remove the water. At 80 degrees, it is possible to reduce the humidity to about 40%, but at 70 degrees the humidity can only be reduced to about 45%, and at 60 degrees or lower often only to about 60% unless in our opinion you have 'oversized' your dehumidifier.
 
2. Auto Defrost. You need a dehumidifier with some kind of auto defrost feature. This process is designed to turn off the dehumidifier’s compressor when the desired humidity level has been reached. This prevents the coils from icing up and allows the dehumidifier to resume removing moisture from the air. The fan will continue to run and draw the warmer air from the room across the evaporator coils allowing them to heat up just enough so the compressor can turn back on. Hot gas defrost is a very effective way, in very challenging basement environments to stop a dehumidifier from icing up as it allows a dehumidifier to accumulate some ice and then remove the ice in a matter of minutes by running a hot gas defrost cycle. Thus the dehumidifier continues to remove moisture from the air at very low temperatures, as low as 33 degrees. Most dehumidifiers without this feature are designed to not allow the evaporator coils to get any colder than 35 to 45 degrees. With the hot gas defrost feature, the coils are allowed to get as cold as 28 degrees. The low pressure cold refrigerant gas is compressed into a high pressure hot gas at the end of the refrigeration cycle. A timer every 45 to 55 minutes on the hour will start a hot gas defrost cycle, so hot gas is circulated through the ice cold evaporator coils allowing any ice to melt. The defrost cycle takes 3 to 8 minutes. Then, the dehumidifier is able to start back up. The hot gas is circulated two ways: the first is what is call reverse hot gas defrost where a valve closes to stop the flow of hot gas before it has a chance to enter the condenser and cool. With the valve closed, the gas backs-up and reverses its direction flow back to the evaporator coils to melt the ice. The second way is hot gas defrost by-pass which is basically the same thing except in this method there is a by-pass valve that opens to re-direct the hot gas, so it by-passes the condenser and flows back to the evaporator coils to melt any ice. Our Fral Dehumidifiers are hot gas defrost dehumidifiers.
 
3. Basements with Dirt Floors. When the air in the basement is dried, any moisture in a dirt floor will be drawn to the surface to evaporate into the air and increase the humidity. This could become a losing battle, especially if one lives near the water, or has a low water table. If you have basement dirt floor, we recommend you create a surface barrier by pouring a concrete floor. An easier less expensive method is to cover it with plastic sheeting and then a thin layer of gravel to hold it down. By creating a vapor barrier the moisture in the ground will not be able to evaporate back into the air which would increase the humidity.
 
4. Automatic restart after a power failure is a plus, especially in a 2nd home where you are not always present, but is not as important in your primary residence where you will notice power outages.
 
5. A Digital Humidistat/Built-in Hygrometer allows you to set a desired humidity level and these dehumidifiers and these are far better than dehumidifiers with a non specific dial for adjusting humidity levels.
 
6. Automatic shut-off is a must feature so that the water will not overflow when the bucket completely fills.
 
7. You should have a Water Collection Bucket which allows you to attach a hose for continuous gravity drainage for easier dehumidifier management. Since most buckets hold between 16 to 20 pints, one of the major inconveniences is emptying the bucket, which in a very humid environment which could happen every few hours. A bucket that is both sturdy and has a built in handle will prevent the irritation of spilling water on the way to dumping it. A convenient alternative is a dehumidifier with built-in pumps.
 
8. Dehumidifiers with built-in pumps are not common, so we sell a convenient Condensate Pump which is capable of pumping the water 15 feet vertically and over 100 feet horizontally. This way you can have the water pumped to a drain, sink, washing machine out-flow pipe, out a window, through a wall, or even to a different floor. You can actually tie it into your plumbing if you wish. Best of all, it works easily with most of the dehumidifiers we carry.