Dehumidifiers are appliances that remove excess moisture from the air in your home. They work by drawing humid air into the unit, condensing the water vapor out of the air, collecting the water in a bucket or draining it away, and then expelling the dry air back into the room. Running a dehumidifier can help eliminate musty smells, reduce allergy symptoms, prevent mold growth, and stop condensation from forming on windows and other surfaces.
However, dehumidifiers do have some temperature limitations. Operating a dehumidifier at very cold temperatures can cause several problems, potentially damaging the appliance and creating icy hazards in your home. Knowing the ideal temperature range for dehumidifier use can help you run your unit safely and efficiently.
What Happens When You Use a Dehumidifier in Cold Temperatures?
Dehumidifiers are designed to work best within a certain ambient temperature range, usually between 41 and 89 degrees Fahrenheit. Using a dehumidifier outside of this range can cause several issues:
Frost Buildup
The coils inside a dehumidifier work to cool air and condense water vapor. When temperatures dip too low, these coils can begin to frost over. The frost buildup will make the coils less efficient at removing moisture. It can also completely block airflow through the dehumidifier. Running the appliance with iced coils can cause the dehumidifier’s compressor to overwork trying to defrost itself, leading to premature failure.
Freezing Collected Water
Most dehumidifiers collect condensed water in a bucket or drain it through a hose. When the surrounding temperature goes below freezing, any water in the collection tank or hose can freeze solid. The ice can block the dehumidifier from working properly or even crack components that aren’t designed to withstand freezing temperatures and expansion.
Room Temperature Drops
Since dehumidifiers cool and dry the air, running one in an already cold room can potentially drop the temperature enough to become uncomfortable or even dangerous. Infants, pets, and plants can be particularly sensitive to cold temperature dips.
Increased Energy Usage
A dehumidifier running in cold air has to work harder to extract moisture. This can lead to much higher electric bills. The appliance’s compressor may stay on constantly just to defrost the iced coils, wasting energy trying to overcome its temperature limitations.
Minimum Temperature for Safe Dehumidifier Use
Most dehumidifier manuals recommend a minimum operating temperature of 41 degrees Fahrenheit. This threshold helps avoid the issues mentioned above.
Below 41 degrees, frost can begin accumulating on the dehumidifier coils. The collected water may also freeze, damaging components. Running the appliance in a cold room could potentially lower the temperature into the 30s or below, risking damage from freezing.
So for safe, effective operation, 41 degrees F is the lowest recommended temperature setting.
Special Low-Temperature Models
Some dehumidifier models are specifically engineered to work in cold conditions down to 33 degrees Fahrenheit. These low-temperature dehumidifiers have features like hot gas defrost to periodically clear frost from coils. They also have insulated housing and cold-tolerant collections buckets.
If you need to use a dehumidifier in a consistently chilly basement or other space, look for a unit rated for sub-41 degree operation. Just be aware that cold temperature models usually cost more than standard dehumidifiers.
Ideal Temperature Range
While 41 degrees F is the recommended minimum, most dehumidifiers will operate even more efficiently within a range of about 59 to 89 degrees. This allows the appliance to strike the right balance between cooling air to remove moisture while not over-chilling the room.
Here are some guidelines for ideal dehumidifier temperature ranges:
59 to 64 Degrees
In this range just above room temperature, a dehumidifier can work well without needing to run the compressor constantly. This prevents overcooling while still condensing decent water volume.Humidity removal may be slightly less than warmer temperatures.
65 to 70 Degrees
This is the minimum temperature setting you should use for a basement or other space where you need maximum moisture removal. Expect the dehumidifier to run often to keep humidity in check.
70 to 89 Degrees
In this broad warm temperature range, most dehumidifiers can operate at peak efficiency. The unit can easily draw ample moisture from the air without excessive chilling. This is the ideal comfort zone for dehumidifier use in living spaces.
Tips for Running a Dehumidifier in Cool Temperatures
If you need to use your dehumidifier in a cooler space like a basement, garage or crawlspace, here are some tips to do it safely and effectively:
– Only operate models rated for the ambient temperature. Look for units rated down to at least 41 degrees F or lower.
– Set the unit to run on lower fan speeds. High fan speed can drop temperatures too drastically.
– Place the dehumidifier away from open windows or doors where cold outside air can blow directly on it.
– Don’t set humidity levels too low. Minimal moisture removal will prevent over-chilling.
– Check coils frequently for frost buildup. Turn off the unit and allow coils to defrost if needed.
– Use a hose to drain water away rather than letting it collect in buckets that could freeze.
– Run the unit intermittently rather than continuously if moisture removal is not critical.
– Use supplementary heating sources like space heaters to keep the room temperature in the optimal 59-89 degree range.
Conclusion
Dehumidifiers work best when ambient temperatures are between 59 and 89 degrees Fahrenheit. Temperatures below 41 degrees can cause frost buildup on coils, freezing of collected water, and unnecessary energy usage. Running a dehumidifier in very cold air can also over-chill a space.
Look for special low-temperature models rated for sub-41 degree spaces. Otherwise, the general rule of thumb is to avoid operating standard dehumidifiers in temperatures lower than 41 degrees for safe, efficient performance. Monitoring conditions and following operating tips can help if using a dehumidifier in a cooler space is necessary.