Let's begin with how dehumidifiers work. Dehumidifier is an electrical appliance that reduces the level of humidity in the air. In general, the fan pulls air inside the cooling coils, the condensation will extract moisture from the air into the reservoir. The dehumidifier will then release back warm, dry air out and the cycle will repeat itself. Most models come equipped with a humidistat so you could regulate the room humidity level. There are four types of dehumidifiers in the market: Mechanical or refrigeration, electronic desiccant, thermoelectric, and ionic membrane. You can also install a whole-house dehumidifier available for both residential and commercial use.
Measure The Room Size
First thing first, you will need to measure the room size to determine what sizes of dehumidifiers you would need. First, get a measuring tape and multiply the room’s length and width for the square footage. You just need a rough number so you could just round up the numbers. For example, a small room with 10 feet width and 10 feet length will have an area of 100 square feet or (9.3 m2). In short:
Length X Width = Room Size
Check The Room’s Moisture Condition
There are plenty of ways you can check room humidity. The common way is with a portable moisture meter to test the room dampness level ideally between 30-50%. You can also use your own senses to detect if there any musty, nauseating mold smell. Try to look for visible condensation on the ceiling or wall. The more condensation you spotted, the higher a room humidity level it will be.
Depending on how bad a room moisture level is, you might a bigger dehumidifier to cover a bigger room. For e.g. a 50-pint dehumidifier can cover 700 sq. ft. room size with 50-60% humidity level but you will need at least a 60-pint dehumidifier to cover a very damp room with 70-80% humidity. To ensure you purchase the right unit to cover a room condition, you can refer to the dehumidifier sizing chart below.
Dehumidifier Room Size Chart
|Room Conditions||Square Footage|
|300 sq. ft.||500 sq. ft.||700 sq. ft.||1000 sq. ft.||1,500 sq. ft.|
|Moderately Damp (50-60% humidity)||30 pint||40-45 pint||50 pint||60 pint||70 pint|
|Very Damp (60-70% humidity)||30 pint||40-45 pint||50 pint||60 pint||70 pint|
|Wet (70-85% humidity)||40 pint||50 pint||60 pint||70 pint||90 pint|
|Extremely Wet (85-100% humidity)||40-45 pint||50-60 pint||60-70 pint||70 pint||90+ pint|
What Size Dehumidifier Size Do You Need?
It highly depends on your room size and environment. Every dehumidifier has a pint recommendation based on manufacturer official figures. Look for models that have the official AHAM stamping mark (humidity conditions of 60%). Association of Home Appliance Manufacturer (AHAM) role is to guide buyers to the right model with standardize testing conditions. The test is conducted based on many pints of water the dehumidifier can pull from the air in 24 hours. The higher the pint numbers, the more air thus water the device can pull in. E.g. 50-pint humidifier is able to remove 50 pints of moisture in a day. In generally, dehumidifiers are divided into 3 groups:
- 30-Pint Dehumidifier – The recommended size for areas is between 500-1,500 square feet. If is a very damp room, the suggested size will be down between 500-1,000 square feet. For a wet room, the size will be down to 500 square feet.
- 40/ 50-Pint Dehumidifier – The recommended size for areas is between 2,000-2,500 square feet. If is a very damp room, the suggested size will be down between 1,500-2,000 square feet. If is a wet room, the size will be between 1,000-1,500 square feet. For an extremely wet and damp room, the size will be down to 1,000 square feet.
- 60/ 70-Pint Dehumidifier – The recommended size for areas is up to 2,500 square feet. If is a wet room, the size will be between 2,000-2,500 square feet. For an extremely wet and damp room, the size will be down to 1,500-2,500 square feet.
Other Factors: Choosing The Correct Size Dehumidifier
Besides knowing the room size and dampness condition, there are other key factors to consider in a dehumidifier as well. If the surrounding environment is very humid like in summer, add another 5-10 pints to the requirement. If the household has more than 3 people in it or there is a washer/ dryer nearby, add another 10 pints. Other points to look at when sizing a dehumidifier is the continuous pump features where you will not have to empty the water tank. The collect water can be pump out directly to a floor drain. Energy Star rated should also be a higher priority as it will save you a lot on electricity bills in the long-run. Lastly, go with models that come with a low fan speed setting so you could operate in a much lower noise level in the bedroom.
Frequently Asked Questions FAQ
What Size Dehumidifier Do I Need for 2500 square feet?
A 70-pint dehumidifier would cover 2,500 sq. ft. room if the room humidity level is still OK. A 90-pint dehumidifier would definitely cover the room size regardless of the humidity conditions.