Pressure drying and dehumidification of layered constructions

  • Why pressure drying is the most effective method

    There are shared opinions on pressure drying as a choice of drying method when drying water damages, especially in living environments. Many water damaged constructions are today unnecessarily torn down and rebuilt which lead to higher costs and longer time to completion. At Corroventa, we believe that pressure drying is the fastest and most effective method when drying layered constructions.

    At all kinds of drying processes you benefit greatly from heat in combination with dry air. To heat up the material that is to be dried you can shorten the drying time substantially. The combination of dry air and heat makes pressure drying so effective. Pressure drying means that you will start by dehumidify air and thereafter create a high over-pressure with a turbine that will press the dry air into the construction where it is normally difficult for the air to circulate. Much heat is created when the over-pressure is created in the turbine. The heat increase the vapour pressure in the moist material and thereby increase the drying speed. The moisture in the construction is being returned to the room by natural openings or drilled holes in the construction where it is once again sucked into the dehumidifier and dried anew before it is forced back into the building construction.

    When is the best time to use pressure drying?

    Pressure drying is preferably used when you want to save time, costs and the environment by avoiding to tear down the construction. When pressure drying is being used, noraml businesses can continue their daily operations and residents do not need ot find alternative accommodations during the process.

    Which construction benefits most from pressure drying?

    • Layered constructions such as joisted walls, sandwich elements, HDF concrete floors
    • Floating floors on concrete plates where water has leaked into the insulation

    What you need to perform pressure drying

    • Drill holes in the floor to be able to get hoses with the dry air in the construction. You might need to drill up to one hole per 2 m2. The most important is to make sure that there is an airflow of 0,5-3 m/s everywhere. The optimal air flow is 1-2 m/s. This is to ensure flow and to keep as much heat as possible in the material.
    • A hose system to spread the dry air in the construction. We recommend Corroventa’s hose system C16 or C25.
    • Adsorption dehumidifier A2 ES or A4 ES
    • Turbine T2 ES or T4 ES
    • Plastic for any plastic enclosuring. Read more about plastic enclosuring.
    • We recommend you to use Corroventa’s ES-machines together with the control system SuperVision® to be able to remotely control the drying process.

    Questions to answer before starting the pressure drying process:

    • What kind of water has leaked into the construction? If facing a leakage of sewage, you need to start by measuring the bacterial content to evaluate whether drying is possible.
    • Have we eliminated all the free water in the room? If not, suction drying together with a water separator should be done initally until you have removed ALL the free water.
    • How large is the surface that we will dry and what material does the filling consist of? If you have an insulation material such as leca and for a surface of up to 45 m2, an adsorption dehumidifier together with a turbine T2 ES is enough. If the surface is up to 75-80 m2 you will need an A4 ES in combination with a T4 ES. If you are drying several rooms, you need to make sure that there is air flow in each room. If the insulation material is compact such as EPS the air flow will be affected and you need a higher machine capacity.
    • The hot and dry air can affect wooden material in the room. Therefore, it is important to remove or wrap wooden furnitures and decorations.
    • Are people in the area affected if particles is transported with the damp air and into the living environment. If the answer is yes, you can limit the surface with plastic enclosureing. Read more about it here. This will also make the dehumidification being concentrated to a smaller surface which makes the process more effective.

    Why use a turbine from the ES-family?

    A dehumidifier and a turbine from the ES-family can easily be connected for an optimized drying process. When connected, the turbine will control the dehumidifier so optimal amount of dry air will be led into the turbine. The turbine from the ES-family also have a build-in feature to prevent the machine from being over-heated. The machines also have many opertion and control modes that will optimize each drying process. You can choose what amount of air and pressure you want the turbine to deliver. The counterpressure is usually high when you start the drying process which demands more from the turbine. As the construction gets drier, the counterpressure gets lower and the machine will then lower its capacity to keep the desired air flow. Corroventa’s ES-machines are prepared so that they can be monitored and controlled remotely with SuperVision®

    We would like to emphasize the importance of always starting the drying process with suction drying to make sure that you eliminate all the free water in the room.