Dehumidifier Calculation in Excel

This excel sheet calculates the dehumidifier capacity for reducing the humidity in a warehouse, cold room, warehouse, industries etc.

How to calculate the capacity of a dehumidifier?

In layman’s language, the dehumidification process is the removal of water from the surrounding air. Bringing down the humidity levels means reducing the moisture content in the air.

So the capacity of a dehumidifier is defined as its capacity to remove the water content. eg. a dehumidifier with a capacity of 24 litres per day means it can remove 24 litres of water in a day. So effectively, moisture content totalling 24 litres can be removed in a day by this particular dehumidifier.

Steps for calculating dehumidification capacity and selecting the right dehumidifier

For any applications covering residential, commercial or industrial, you can calculate the dehumidification capacity and select a suitable dehumidifier as per the following steps:

1. Measure the present temperature (°C or °F) and present relative humidity (%RH).
2. Decide the humidity level you want to achieve and maintain (%RH).
3. Measure the size of the room or warehouse. Length, Width & Height are required. Calculate the volume of the room by multiplying Length, Width and Height.
4. If you have an existing HVAC system, check the fresh air intake percentage.
5. Convert the present relative humidity into absolute humidity.
6. Convert the desired relative humidity into absolute humidity.
7. Find out the difference between the values of Sl. nos. 5 & 6 above. This is the volume of moisture content to be removed from one cubic meter.
8. Multiply the result obtained in step 7 by the total volume of the room.
9. This gives the total required capacity of the dehumidifier in litres per hour at the measured room temperature. Now you can select the right dehumidifier matching the capacity.
10. If your room temperature is above 10°C, you may go for a condensation dehumidifier. If the room temperature is below 10°C, you may choose a desiccant dehumidifier.
11. Please note that the capacity of a dehumidifier varies as per the temperature. Hence never select a dehumidifier based on its maximum specified capacity. Please look for the performance chart of the dehumidifier. This will indicate a performance graph at different temperatures. You may select the right capacity at your room temperature.

Details required to calculate de-humidification capacity

In order to calculate the required capacity of a dehumidifier, you need to collect the following details:

1. The size of the room in cubic meters.
2. The present temperature of the area, preferably the maximum recorded temperature reading.
3. Present or maximum humidity levels without a dehumidifier in %RH (You can use a data logger or hygrometer to find out the same. Datalogger will record the data over time. Hygrometer will not record the data, but only will display on the screen.)
4. Required humidity level to which you want to reduce the humidity levels in %RH.

Method for calculating de-humidification capacity

All the normal humidity measuring instruments will indicate the humidity levels in %RH. This has to be converted to absolute humidity which means the amount of moisture per cubic meter. Absolute humidity will be automatically calculated in the excel sheet for Sl. no. 3 & 4 defined above.

The difference between the absolute humidity of 3&4 above gives the moisture content to be removed from 1 cubic meter.

Multiply this result by the volume of the room which will provide the total volume of the water to be removed from the room to bring the humidity down to the desired levels.

We supply all types of dehumidifiers in the United States of America, United Kingdom, Germany, France, Netherlands and all other European countries.

Also, we supply these dehumidifiers in Asian countries covering India, Pakistan, Hong Kong, Singapore, Srilanka, Bangladesh, Kuwait, Oman, Qatar, United Arab Emirates, Kingdom of Saudi Arabia, Bahrain, Iraq, Afghanistan, Kazakhstan etc. Our Dubai office supplies dehumidifiers across the entire Middle East countries including Lebanon, Syria, Egypt, Jordan, Libya, Tunisia etc.
In Africa, we supply these dehumidifiers to all countries including South Africa, Ghana, Angola, Kenya, Algeria, Tanzania, Djibouti, Chad, Rwanda, Uganda, Nigeria, Ethiopia, Morocco, etc.