A combination of pressure- and suction drying
The push-pull method is an effective drying method where the risk of particles from the construction spreading to the air in the living environment is minimized. The method combines two different drying methods, one for positive pressure (pressure drying) which consists of an adsorption dehumidifier and a turbine, and a method for negative pressure (suction drying) where a water separator and a turbine are used.
By evacuating the wet air outdoors, both from the turbine working with the water separator and from the adsorption dehumidifier paired with the turbine, you get an installation that will be very fast and quiet. This combination evacuates the moisture from both construction and room air in a fast and efficient way instead of pushing the moisture back in to the room to process it with an additional dehumidifier. Compared with using only suction drying, the warm and dry air from a dehumidifier that is pushed by a turbine into the construction decreases drying time significantly. Each inserted m3 of warm and dry air helps to carry moisture out of the construction; the warm and dry air coming from the pressure drying side significantly increases drying speed.
To properly perform push-pull drying, it is also essential to have a correct balance of air going in and out of the construction being dried. To limit the risk of polluting the air in the room, the airflow that is drawn from the construction should always be higher than the airflow pushed into the construction. A very effective and safe way to achieve this is by using Corroventa’s intelligent ES-series. On the ES-turbines, you can easily maintain the right balance by using the turbines’ Relation mode.
The great advantage with using Relation mode is that the ES turbines can automatically adjust airflow when needed and therefore have a controlled airflow relation throughout the entire drying process. Another great advantage with the ES-series is that you can use the Pressure drying mode on the adsorption dryer providing the turbine with dry air. The “Pressure drying mode” makes sure the turbine is provided with an optimal airflow of dry air reducing drying time and energy consumption.
HOW TO PREPARE FOR PUSH-PULL DRYING
There can be vast amounts of water trapped in a layered floor construction after a water damage. It is therefore recommended, regardless of drying method, to always use a water separator in combination with the turbine that creates negative pressure from start. In doing so, the risk of sucking water directly into the turbine and damaging it is eliminated as well as the risk that the turbine creates overpressure, pushing water further away from the initial damage.
Before Push-pull drying you must, as always, locate and examine the water damage. Make sure that the water damaged construction enables airflow between the push- and pull side. The position of the holes shall enable an airflow through the water damaged area. There can be vast amounts of water trapped in a layered floor construction after a water damage. Depending on the amounts of water and the construction, it can sometimes be recommended to start with a suction drying session. In doing so, the risk of the turbine creating overpressure in the push-pull method, pushing water further away from the initial damage, is eliminated.
Please note that in small, confined spaces with poor ventilation, some materials such as wood can be affected by an increased room temperature caused by heat from the equipment. When drying smaller confined spaces, a proper ventilation is necessary to prevent the temperatures from rising too much as it could hinder the drying process or damage materials.
ADVANTAGES USING THE PUSH-PULL METHOD
Using the Push-pull method, the warm and dry air is confined within the layered construction without entering the room. Therefore, the room climate is not affected in the same way as using other drying techniques. The warm and dry air is always directed into the water damaged construction and the drying is performed in a very energy efficient way.
That brings another two advantages. First, the drying becomes almost independent from changes in the room climate (e.g. windows and door etc.). And second, since there is no need to dry the entire room, rather just the insulation layer in a construction, critical materials in a room will not be affected in the same extent. That is the reason why the push-pull drying method is much faster and more efficient. Often it also enables the property owner to use the room during the whole drying process.
PRODUCTS YOU NEED
- 1x Adsorption dehumidifier, for example A4 ES.
- 2x Turbines, for example T4 ES.
- 1x Water Separator.
- 2 x Hose system C25. Note! More C25 systems may be needed to meet the correct air flow.
- Hoses: Ø50mm to connect the turbine and Ø75mm Wet air hose from the dehumidifier.
ADDITIONAL PRODUCTS TO OPTIMIZE THE PROCESS WITH MINIMAL DISRUPTION FOR THE RESIDENTS: