What Size Dehumidifier Do I Need? Complete Analysis With Calculation

What Size Dehumidifier Do I Need

A dehumidifier is a vital companion with a heating and cooling device at home. When browsing for quality HVAC equipment, you should look for a good dehumidifier that works perfectly according to the size of the house and the humidity of the area/locality. 

While searching for the dehumidifier, customers are often confused about the ideal size and impact on water extraction. We will explain all the required aspects that need to consider and the perfect size for your home in the article. 

What Is Dehumidifier size?

Dehumidifier size is not physical dimensions. It is capacity to extract water in a day. Generally, large capacity dehumidifiers come in bigger sizes, though it’s not the case with all brands and models. Manufacturers of HVAC equipment mention the capacity separately, usually ranging between 2 to 6 liters. 

What size dehumidifier do I require?

We will explain factors that need to consider for the size of the dehumidifier at home

Humidity Level at Home/Room

Humidity level at home is the most crucial element to consider the size of the dehumidifier. Check wet floor, dampness, humidity level through hygrometer and decide on the size accordingly. It is pretty obvious that a dehumidifier will work harder for a highly wet place than for minor damp in the room.

Place the hygrometer in the room that you want to check for moisture, follow the instructions given on the product, and refer to the results for deciding the size of the dehumidifier.

You can also analyze moisture level through self-assessment through checks such as the presence of mold, always dampness, visible condensation on the walls & ceilings, place with musty smell during humid weather conditions, etc.

Observe Room Temperature

Use a thermometer to check the temperature in the room. You can download the application and analyze average room temperature through smartphone sensors.

Measure Size of the House/Room

The place you want to dehumidify is another vital factor to consider. You need to measure length, width and multiply both to get the square footage of the area.

Example to Explain Measurement of the Room/House

Take into consideration a room with a length of 15 ft and a width of 20 ft. 

Size of the room:15×20=300 square feet

How to Calculate What Size of the Dehumidifier Do I Need?

After deciding the size for the dehumidifier, it’s time to explain calculation methods currently in use, according to the US Department of Energy.

Two standards to measure the size of the dehumidifier;

  • Old Standard started in 2012
  • New Standard began in 2019

US Department of Energy also makes changes in sizing standards. Earlier dehumidifiers used 70 pints, and now they come in 50 pints.

Old Standard began in 2012 was based on Energy Factor. New Standard of 2019 started working with Integrated Energy Factor. It is a more accurate method to calculate the required size of the dehumidifier.

New Standard measures dehumidifier at a lower temperature (65 degrees F), and Old Standard testing temperature was 80 degrees Fahrenheit. Currently, both systems are in use, and so, you can see them on the size calculator and chart. 

*Old Standard will discontinue after 2022 as per the US Dept. of Energy notification.

Dehumidifier Size Chart

Multiple factors decide the size of the dehumidifier. In addition, Government regulation also changes standards to measure required size.

To ease your hunt, we have created a sizing chart according to the latest dehumidifier testing standards 2020. As per new changes, testing is done in colder temperatures that lower total pint capability than the older standards.

Sizing Chart

Humidity Levels:300 sq ft Space500 sq ft Space800 sq ft Space1,200 sq ft Space
50-60% Humidity(Air feels slightly heavy)30 Pint (Old Standard), 20 Pint (New Standard)45 Pint (Old Standard), 30 Pint (New Standard)60 Pint (Old Standard), 40 Pint (New Standard)70 Pint (Old Standard), 50 Pint (New Standard)
60-70% Humidity(Occasionalmusty smell)30 Pint (Old Standard), 20 Pint (New Standard)45 Pint (Old Standard), 30 Pint (New Standard)60 Pint (Old Standard), 40 Pint (New Standard)70 Pint (Old Standard), 50 Pint (New Standard)
70-80% Humidity(Wet spots on walls or floor)40 Pint (Old Standard), 25 Pint (New Standard)50 Pint (Old Standard), 30 Pint (New Standard)65 Pint (Old Standard), 45 Pint (New Standard)80 Pint (Old Standard), 55 Pint (New Standard)
80-100% Humidity(mold possible)45 Pint (Old Standard), 30 Pint (New Standard)60 Pint (Old Standard), 40 Pint (New Standard)70 Pint (Old Standard), 50 Pint (New Standard)90 Pint (Old Standard), 60 Pint (New Standard)

Several conditions inflate humidity than usual conditions at home. These include:

Small Accommodation

In smaller houses or apartments, washers and dryers generally stay closed because of the low space to keep them at a distance. In such places and conditions, humidity can increase up to 5 pints. It means if your room measurement requires 10 pints, consider 15 to 20 pints for a dehumidifier.

Humid Climate

A humid area outside affects humidity inside so, and it is advisable to add 10 pints to the size required for the dehumidifier at home.

For example, Florida and Alaska experience higher humidity, whereas New Mexico and Colorado are low humid areas. Therefore, if you stay in the former States, you need higher pints and more down pints in later States.

If your room requires 50 pints dehumidifier, add 10 pints more for high humidity outside.

Kitchen Area with Dehumidifier

According to the standard calculation, if your HVAC equipment is in the kitchen or surrounding area, add 5 pints with the required size.

Air Conditioners

You should buy a smaller dehumidifier if you use an air conditioner and dehumidifier together during Summers. AC and dehumidifiers work almost similarly, so buying smaller units save power and dollars.

Dehumidifiers also help pets to stay comfortable. In the humid environment, they lose furs, and with a controlled indoor environment, they will be safe.


We know choosing a dehumidifier takes a lot of time for browsing, comparing, and deciding. The task becomes further troublesome with dozens of brands and models available in the market.

You also need to measure room size, consider temperature and climate conditions, etc. We hope this article will help as a quick reference to decide the right size for the dehumidifier.

Related Articles You May Like

Scroll to Top