Dehumidifier Capacity Calculation

Calculation method

Present humidity and desired humidity are defined as %RH which means as a percentage of the total volume of the air. This has to be converted into absolute humidity, which means real amount of moisture content in terms of grams per each cubic meter. The difference of the present humidity level and the desired humidity level is the amount of water to be removed.

Note:The calculation is true to the best of our knowledge at the time of development and we bear no contractual obligations whatsoever for the results or the calculation method.


Brief explanation of the input fields are given below
a. Present temperature (°C) is the normal working temperature of the area in degree centigrade
b. Present humidity is the humidity level measured in %RH. You can measure the same using a hygrometer or humidity data logger
c. Desired humidity is the humidity level to be achieved after installation of the de humidifier.
d. Room size has to be given is meters or if you know the volume, you can input the volume in cubic meters.

Dehumidifier Capacity Calculation

In HVAC, dehumidification is a relatively frequent operation. The capacity of a dehumidifier refers to the amount of moisture or humidity that it can remove from the air within a certain time period. The dehumidification capacity of a dehumidifier depends on its size, power, and the conditions of the environment it is operating in, such as the temperature and humidity levels. The higher the capacity of a dehumidifier, the more moisture it can remove from the air in each time period.

It's important to note that the dehumidification capacity of a dehumidifier is not a fixed number and can vary depending on the conditions it is operating in. Higher humidity levels, lower temperatures, and larger room sizes can all affect the dehumidification capacity of a dehumidifier.

How to Calculate the Capacity of a Dehumidifier?

Dehumidification, to put it simply, is the process of removing water from the air. Lowering the air's moisture content results in lower humidity levels.

The ability of a dehumidifier to extract water is therefore defined as its capacity. For instance, a dehumidifier that can remove 24 litres of water per day has a capacity of 24 litres. This dehumidifier is so efficient that it can eliminate 24 litres of moisture in one day.

The dehumidification capacity of a dehumidifier can depend on several factors, including:

1. Size of the room or space
The size of the room or space being dehumidified is a critical factor in determining the dehumidification capacity required. A larger room or space will require a dehumidifier with a higher capacity to effectively remove excess moisture.

2. Humidity level
The higher the humidity level in the room, the more moisture the dehumidifier will need to remove to achieve the desired humidity level.

3. Temperature
The temperature of the air affects the dehumidification capacity of a dehumidifier. Lower temperatures may reduce the dehumidifier's ability to remove moisture from the air, while higher temperatures may increase it.

4. Airflow
Proper airflow is essential for efficient dehumidification. A dehumidifier that is not placed in an area with proper airflow or has a clogged or dirty air filter may struggle to remove moisture from the air.

How to determine dehumidification capacity and choose the ideal dehumidifier?

You may determine the dehumidification capacity for any application, whether it be domestic, commercial, or industrial, and then choose an appropriate dehumidifier by following the steps below:

1. Calculate the current relative humidity (%RH) and temperature (°C or °F).
2. Determine the desired and desired humidity level (%RH).
3. Determine the room or warehouse's size. Height, Width, and Length are needed. Multiply the room's length, width, and height to find its volume.
4. Check the fresh air intake % if you already have an HVAC system.
5. Calculate the absolute humidity from the current relative humidity.
6. Make the appropriate absolute humidity from the desired relative humidity.
7. Find the difference between Sl. nos. 5 and 6's values. The amount of moisture that has to be removed from one cubic metre is this.
8. Multiply the value from step 7 by the room's total volume.
9. This provides the dehumidifier's total necessary capacity in litres per hour at the determined room temperature. Now you may choose a dehumidifier based on its capacity.
10. A condensation dehumidifier may be used if the room temperature is over 10°C. A desiccant dehumidifier is an option if the room temperature is below 10°C.
11. Please be aware that a dehumidifier's capacity changes depending on the temperature. Dehumidifier selection should never be based solely on maximum capacity. Please seek the dehumidifier's performance chart. This will provide a temperature-dependent performance graph. At your chosen room temperature, you can choose the appropriate capacity.

An illustration of how to calculate dehumidification capacity

In the example that follows, the computation is described.

The following values are presumed:

1. The room's current temperature is 30 °C.
2. The room has a 70% relative humidity now.
3. 50% RH is the ideal humidity for the space.
4. 5 mtr (L) x 5 mtr (W) x 3 mtr (room size) (H).

The following may be calculated from the example above:

1. Absolute humidity equivalent to 70% relative humidity weighs 21.23149 grammes per cubic metre.
2. 15.16535 gram/cubic metre is the absolute humidity value corresponding to 50% relative humidity.
3. 75 cubic metres is equivalent to the volume of the room, which is 5x5x3.
4. 6.07 gram/cubic metre separates items 1 and 2 above. To attain 50%RH, 20 gramme of water must be eliminated from each cubic metre.
5. Consequently, 455 gramme per hour of dehumidification capability is needed for a volume of 75 cubic metres (6.07 x 75 ).
6. This is equivalent to 0.45 litres per hour or 0.45 kg per hour. In terms of daily values, this comes out to 10.92 kilogrammes or 10.92 litres per day.

How can you figure out a dehumidifier's pint/day capacity?

The data are presented in litres per day above. Please apply the correct conversion if you wish to convert the capacity into pints per day. You may calculate a pint per day from a litre per day using the multiplication factor 2.11337642 for translation into US pints.

Contact our professionals to choose the right dehumidifier for you -

Type of dehumidifiers:

We are undertaking supply, installation, testing and commissioning of various types of dehumidifiers. The major categories are listed below:

Dehumidifiers for cold rooms

These are used for walk in freezers, cold rooms etc. desiccant types are generally used for such low temperature environment.

Read More about Dehumidifier for Cold Rooms

Dehumidifiers for warehouses

Warehouses for storage of medicines, food, vegetables, tobacco etc. need high capacity dehumidifiers

Read more about Dehumidifier for Warehouses

Dehumidifiers for swimming pools

Swimming pools generate huge amount of humidity and needs special dehumidifiers of high capacity.

Read more about Dehumidifier for Swimming Pools

Dehumidifiers for homes and offices

These are sleek, stylish models of small to medium range of capacity machines. There are numerous models to suit your ambience.

Read more about Dehumidifier for Offices & Homes

Industrial dehumidifiers

Various industries require controlled humidity during the manufacturing process and storage. These are high capacity machines.

Read more about Industrial Dehumidifiers