Dehumidifier Output: How Hot Is Too Hot?
Legend Brands Service sometimes receives calls from customers expressing concern about the temperature of the output air of their Dri-Eaz dehumidifier. In some circumstances, the temperature can seem extra warm and catches the attention of a watchful restoration tech.

What causes higher temperatures in dehu output air? Is it supposed to be so warm? The answer is: It depends. A properly operating refrigerant dehumidifier will typically raise the temperature of the air flowing through it by 10°-15°F. For example, if the ambient temperature in a drying area is 90°, an output temp of 105° is quite normal. On the other hand, if the ambient temperature is 70° and the air coming out measures 105°, this 35° rise warrants further investigation.

Here are the two main reasons the output of your dehu might exceed the normal 10°-15°F temp rise:
  • Restricted airflow, typically caused by a clogged air filter, can cause the output temperature to rise. Check and replace as needed. If necessary, clean the interior of the unit as described in the owners manual.
  • The dehu defrost mode may temporarily boost output temperature. The temperature will return to normal once the unit has completed this cycle.
If neither of these situations is true and your unit is still producing excessive heat, your unit may require service. Contact your authorized service center for assistance. Before you call, be sure to make a note of the ambient conditions where the unit is operating. This information may help the service tech diagnose the situation.

Note that refrigerant LGR dehus do not operate efficiently in humidity levels below 20% RH. Regular refrigerant dehus stop removing moisture at 40% RH or below. In those conditions, refrigerant dehus can do little more than add more heat to the environment—and needlessly consume energy. If you need to get RH values lower than this, consider using a desiccant dehumidifier. Desiccants can produce air with a relative humidity as low as 0%, and can also operate in below freezing conditions.