Retail listings size dehumidifiers by floor area: "up to 30 m²", "up to 70 m²". Engineers size them by moisture load, the litres of water that enter the air each day.
Why floor area is the wrong number
A 3-bedroom apartment with double glazing, two showers a day, indoor laundry and a family of five has a far higher load than the same plan used by one person. Ceiling height, glazing, how often doors open and whether fresh air is brought in all change the answer.
What adds to the load
- People: breathing and perspiration, all day.
- Bathrooms and kitchens: showers, kettles, cooking.
- Laundry dried indoors: litres per load.
- Infiltration: every opened door in July, leaky ducts, a fresh-air intake without drying.
- Pools, spas and plants.
Rated capacity vs real yield
A 20 L/day rating is measured at 30 °C and 80% RH. In a room cooled to 24 °C the same unit removes less, which is why "is 12 L enough" depends on the room, not the box.
The sizing table
The calculator
Until it is live, follow the steps below and send the figures for a sized answer.
Key points
- Size by moisture load, not floor area: people, showers, cooking, laundry, pool and fresh air all add water.
- Rated capacity at 30 °C and 80% RH overstates what a unit removes in a cooled room.
- A 3-bedroom villa and a 3-bedroom apartment need different capacities because of glazing, doors and ceiling height.
Step by step
How to size a dehumidifier for a UAE home
- 1
Measure the current humidity
Log a hygrometer in the worst room at dawn and before bed for a week. The gap between the reading and 50% is the work the unit has to do.
- 2
List the rooms and their volume
Floor area times ceiling height for every room the system should treat. Double-height living rooms and open stairwells count in full.
- 3
Count the moisture sources
Occupants, bathrooms used daily, the kitchen, indoor laundry, plants, a pool or spa. Each adds litres per day that the unit must remove.
- 4
Note how sealed the home is
Double glazing and closed doors keep moisture in; frequent door opening, a fresh-air intake or leaky ducts bring humid outdoor air in and raise the load.
- 5
Pick the capacity band with a margin
The capacity band for each property type comes from the supplier datasheet at UAE conditions. Until it is published, an engineer confirms the band on a survey.
