How is the efficiency of dehumidifiers measured


Dehumidification by means of condensation has the advantage that a high level of dehumidification can be achieved with little energy. The prerequisite for this is a room temperature of over 10 ° C. The efficiency drops significantly below this temperature. For lower temperatures and / or a target humidity of below 40% RH, dehumidification using an adsorption dryer is ideal.

We have specialized in the dehumidification of rooms in the lower temperature range, as we find them in shelters, civil defense systems, tunnels, storage rooms and basements. We use mobile or permanently installed dehumidifiers, depending on the requirements.



Condensation dehumidification products

We have developed the Lunor L-25/45/75 air humidifier specifically for cellars, warehouses, archives, garages and businesses, tailored to the climatic conditions in Switzerland. Thanks to the hot gas defrosting, operation at lower temperatures is ensured.

As a console model with an installation height of only 40cm! This means that there is a suitable assembly location even in occupied basements or full warehouses. Available with brackets for wall or ceiling mounting.

As a mobile dehumidifier with direct hose connection (suitable for rooms with floor drains).

We achieve the best dehumidification values ​​at temperatures of 15 ° C, which corresponds to the average temperature in the basement.


Type Lunor L-25 Lunor L-45 Lunor L-75


at 15 ° C 60% RH

Liters / 24h 9.2214.6623.65

Dehumidifier COP

Liter / kWh0.991.131.33
sounddB (A)676362



  • Overflow protection for the mobile dehumidifier
  • Hour counter
  • External hygrostat for more precise and easier regulation of the humidity


Custom made:

Your company color is orange and you would like a suitable housing color? The situation calls for an overflow protection device for a console model? Do you need a special coupling for connection to the condensate hose? A lot is possible, give us a call.



How does condensation dehumidification work?

In vapor form, liquid or solid

Depending on its physical state, water is vapor, liquid or solid. Our ambient air always contains a certain amount of moisture in the form of water vapor. The warmer the air, the more moisture it can absorb. If the air cools down, the situation is reversed: the air can no longer hold the moisture, it condenses on cold surfaces.

Lunor dehumidifiers of the L series work according to this principle. Refrigerant is evaporated in a heat exchanger by means of a compressor, which greatly cools its surface (the evaporation temperature depends on various conditions). The humidity flowing past it condenses, the air warms up again and is blown dry and warm to the room.


Relative humidity / effective amount of water in g / kg air

The term relative humidity means that the air is saturated to the stated percentage. When we talk about 60% relative humidity, this number only means that one unit of air is 60% saturated with water. We do not know how much water that is effective in g / kg. We only know that the air is still able to absorb another 40% before condensation occurs. We also need the information at what temperature - and if you take it exactly, also at what air pressure - the corresponding measurement was made.

From the HX diagram we can read that air with 60% RH at 20 ° C at approx. 450 meters above sea level. contains an effective amount of water of 9.2g / kg air.

If we cool this air down to 16 ° C, the relative humidity increases to 80% RH. But it still contains 9.2g of water per kg of air. If we now create a cold surface, which we cool down to below 12 ° C, the humidity increases to 100%. The water vapor begins to condense, we speak of the dew point reached.

Bathroom mirror or cellar wall - the principle remains the same

The theoretical approach is easy to understand when, after showering, your own reflection is no longer visible due to the smallest drops of water. The colder mirror acts as a natural dehumidifier, the shower steam condenses on the cold surface. The phenomenon is best visible in the mirror, but the walls, ceiling and floor are also covered by the finest condensation.

These physical principles lead to enormous moisture damage, especially in uninsulated basement floors. If warm and humid outside air cools down in the basement, the relative humidity increases. Moisture damage to stored goods occurs from 65% -70% RH, of course always depending on what is stored. If the humidity is constant at 65-85% RH, mold can form and grow.

Outside air may only get into the basement if the effective amount of water in the air supplied is lower than the existing air in the basement. As a rule of thumb, this condition only applies in the cold winter months. Dehumidification via ventilation requires a lot of know-how and may only take place with a well thought-out control.

Control and monitoring

An efficient refrigeration unit requires a well thought-out control system so that dehumidification can run efficiently. The most important thing is the placement of the hygrostat (the measuring point), which decides on the operation of the system. All Lunor dehumidifiers are hygrostat controlled. Simple on / off control or control via a timer is not recommended.

The aim is to monitor and, if necessary, dehumidify the room climate. That is why the hygrostat must also measure the room climate. The sales argument "internal hygrostat" suggests security, but often leads to incorrect measurement results and thus to unnecessary running times and energy consumption. If the hygrostat is placed in or on the device, it must be ensured that it measures the room climate and not a microclimate that occurs in the dehumidifier.

Internal hygrostat

With Lunor dehumidifiers, the hygrostat is always located outside the device. As standard on the housing, on request an external hygrostat is available instead of the hygrostat on the device.

External hygrostat
The external hygrostat allows the measuring point to be shifted by several meters and into other rooms. Specifically, measurements are not taken in or on the dehumidifier, but a few meters away. The external hygrostat thus contributes to the more precise regulation of the air humidity in the entire room to be dehumidified.


Adjust the hygrostat correctly

The adjustment of the dehumidifier takes place over a longer period of time. A hygrostat with display located in the room (available from specialist dealers or from Lunor) shows the measured relative humidity in the room as a percentage. If this value is too high, turn the hygrostat lower. If the value is too low, the value can be corrected upwards.


Available optional controls to monitor dehumidification:


Monitoring of the dehumidification performance
If, despite the signal from the hygrostat, no dehumidification takes place, the monitoring system sends a signal to the building management system via a potential-free contact.

Climate monitoring
In contrast to the monitoring of the dehumidification performance, the climate monitoring sends a signal to the building control system when the relative humidity is above a defined maximum value. This prevents moisture damage from occurring due to incorrect manipulation of the dehumidifier: If the humidity rises too high, either the hygrostat on the dehumidifier is incorrectly set, the dehumidifier has been unplugged or it is defective.