Honeywell TP Series

What are Dehumidifier Testing Standards, and What Do They Mean Today?

In 2019, the United States Department of Energy (DOE) changed the pint capacity and efficiency standards for dehumidifiers. What are the practical implications of these changes, and how much do they matter when shopping for a new dehumidifier?

What are DOE Testing Standards?

Every dehumidifier must undergo testing in order to be sold in the United States. The DOE determines the methods used to establish dehumidifier performance ratings. The two main ratings used for dehumidifiers are pint capacity and energy efficiency.

  • A dehumidifier’s pint capacity is the amount of water it extracts from the air per day.
    • Pint capacity is one of the most important factors to consider when purchasing a dehumidifier. If you will be using your dehumidifier in a large, humid room, you will require a unit that has a higher capacity than if you were using it in a smaller, less damp space.
  • A dehumidifier’s energy efficiency is how many liters of water can be removed per kilowatt-hour (kWh) of energy consumed.
TP70PWK with bucket

How Have DOE Testing Standards Changed?

Pint capacity


  • In 2012, the DOE made changes requiring dehumidifiers to be tested in an environment with an ambient temperature of 80° F and a humidity level of 60%. The results of these tests led to the proliferation of the 30-, 50-, and 70-pint dehumidifier models that have become the norm during the last 10 years.


  • In June 2019, the DOE changed its testing standards. Now, dehumidifiers are instead tested at 65° F—a full 15° F lower than the previous ambient temperature criteria. This change was made to better reflect the conditions of basements, which are typically cooler spaces and which are the most common use case for dehumidifiers.
  • Cooler air holds less water vapor, which means under these conditions, dehumidifiers remove fewer pints of water from the air per day. Based on these new testing methods, standard pint capacities were changed to 20, 30, and 50 pints.

Energy efficiency


  • DOE standards in 2012 rated each dehumidifier’s efficiency using a metric called an Energy Factor (EF). These efficiency tests were conducted when the dehumidifiers were turned on and actively removing moisture from the air.


  • New 2019 dehumidifier efficiency standards are based on an Integrated Energy Factor (IEF). Unlike the EF, the IEF incorporates the energy consumed when a dehumidifier’s fan is running but its refrigeration system is off. Because the IEF includes the energy a dehumidifier uses when it has cycled off, it more closely represents the dehumidifier’s expected annual energy consumption.
  • Just like with pint capacity testing, IEF testing is now conducted at 65°

Pint Capacity Equivalencies

The following table reflects 2012 pint capacities compared to 2019 pint capacities.

2012 Pint Capacity

2019 Pint Capacity
















For example, a Honeywell TP50WKN Dehumidifier removes up to 50 pints by 2012 standards and up to 30 pints by 2019 standards. Remember: Dehumidifier performance hasn’t changed from 2012 to 2019; rather, the way performance is measured has.

Final Takeaway

  • Dehumidifiers are now tested under new conditions that result in a reduction of their pint capacity rating and a change in their energy efficiency value. The dehumidifiers themselves haven’t changed; however, the environment in which they’re tested has.
  • Instead of being tested in an 80° F environment, they’re now tested in an environment of 65° Because air in this cooler environment holds less water, there are fewer pints of water that are removed per day.

No changes have been made to the units themselves, only to the method of testing.

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