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Pressure stations


Regardless of ourdoor temperature

One challenge in many pressure stations for fresh water is that condensation is easily formed on the surface of the cold pipes. Although the air in the station may appear to be dry, there is often still water in the air. Hot air can hold more moisture than cold. This means that the temperature at the surface of the cold pipe causes the moisture contained in the “dry” air to form drops on to the pipes as the surface of the pipe usually hold a temperature below 10 °C. That is why the dew point at the surface of the pipe is important. The temperature for the dew point is what needs to be controlled so that the relative humidity level is correct.

In some cases the air in the station is kept warm to control the level of the relative humidity. It may help to avoid mold in the station, but do not to avoid corrosion on the cold pipe surfaces. Because warming up the air does not actually remove any water from the air, but only allows the air to hold more water – this still doesn’t address the challenge with the cold surfaces described above. That is why we strongly recommend to use dehumidifiers to remove the moisture from the air. And to this with a product based on technology that works equally efficient in cold temperature.


What is needed to avoid corrosion and mold is a controlled humidity level lower than 60% relative humidity (Rh). This requires a controlled relative humidity at temperatures that are relevant for the building. See the Mollier diagram where the curve of condensation (saturation) is given at different relative (Rh) levels at different temperatures.

We recommend having a dew point sensor connected to the air dehumidifier for pressure stations. This has proved to be the best solution in a number of installations. The sensor measure the temperature of the coldest area in the room (typically the pipes) and then controls the dehumidifier to extract the amount of water needed from the air to prevent condensation or mold.


Our technology makes it possible to avoid doing any damage to walls or to install piping to take out air from the building. This makes it very easy and cost effective to install. And our technology is just as energy efficient in low temperature as in warm. The dehumidifier can be mounted on a wall mount, to keep the floor is  free in the station building.

The water is easily handled using a hose lead to a drain. If there is no drain available, it is possible to use a collection tank or a pump controlled by the dehumidifier.


Heating using a typical electrical element consumes just over 3200 kWh per year. An airwatergreen dehumidifier consumes an average of 500 kWh in a normal-sized pressure gauging station. It generates a considerable saving in energy and eliminates the costs of renovation due to rust and mold removal.


Airwatergreen has a large number of installations in pressure stations, pump stations and pipe galleries. In some cases, the air dryer works independently to the set dew point and in other cases it is connected to an existing control system. The products are built to withstand the tough environment that applies with few moving parts and selected materials and with an IP63 rating. The air passing the dehumidifiers is not only dehumidified but also filtered removing any dust or insects. It creates a good condition for a healthy working environment!

Our dehumidifier is called FLEX and has a capacity of 5 liters of water per day, which is more than enough in a normal-sized pressure gauging station.

If higher capacity is needed the REX model may be relevant.

The FLEX delivery package contain:

  • Wall mount
  • Dew Point Transmitter

Service agreement
Do not hesitate to contact us for a climate investigation to define the moisture levels and to design a suitable solution for your business!


Different pressure station installations