Steam directly moving downwards!

Sandwich-type steaming is the most effective and energy-efficient surface steaming method. In this further development of the hood steaming method, the hot steam penetrates deeper into the soil.

The steam is led under the hood via a number of hollow pins, each of which has several exit holes. These pins penetrate the soil up to a 25cm depth.

Soil temperature of more than 85°C can be achieved under the covered surface very evenly and quickly with this method. Sandwich-type steaming is efficient for soil depths between 10 and 25cm.

The energy consumption is very low due to the shorter steaming time, which is radically reduced because of the deep penetration of the hot steam.

At 25cm steaming depth, you can count on heating oil consumption of merely 0.6 litres per square metre to reach up to 85°C depth temperature within just five minutes.

At steaming depths beginning from 10cm, sandwich-type steaming saves about 35% in energy compared with normal hood steaming.

When using spiked hoods, the same standard values as for hood steaming are largely applicable.

The important difference is that more than double the quantity of steam per square metre comes under the hood due to the hollow spikes. This requires generation of a slightly higher surface pressure. Such pressure can, however, mostly be provided by the weight of the device itself. Furthermore, moving a spiked hood is a slightly more complicated process since you have to check that the hollow pins have smoothly penetrated into the soil when being lowered.

In this steaming system, you must ensure that the soil is sufficiently dry in order to keep the exit holes clean.

Moreover, the sandwich-type method is ideally suitable for steaming treatment of substrates and flow pots, which means you don’t have to empty and re-fill them.

The surface performance per cycle depends on the steaming depth, as well as on the size of the boiler and hood.

Depending on the soil properties and ambient temperature, the steaming time for one working cycle is about 5 minutes for 25cm steaming depth and at about 80°C soil temperature.