When not heated, the upper concrete slab, that is the floor upper level, conveys the heat from the area outside the cold room’s doors to the inner room. Thus the concrete slab temperature falls along the direction of the heat flow from the room temperature outside area absorbs a remarkable quantity of humidity and keeps it in the form of gas, on the floor colder surface the air humidity condenses proportionally to the much lower capacity of the colder air near the concrete floor to absorb humidity.
Beside the hazardous frost formed on the driveway in the cold room, which endangers loading and unloading operations in the room, the frost on the door lip seals can be a serious problem, too. In fact the lip seals, that are particularly delicate when high sealing capacity is required, are quickly destroyed and it is often necessary to use force to open the doors.
Floor damages are also to be expected. To avoid this waste of energy floor, heating mats can be used. Even with frequent opening of the doors the heated floor surface prevents the outside air flowing into the cold room from releasing the absorbed humidity, particularly on the critical transit area. The hot air penetrating the cold area has a lower density and therefore moves upwards to release its humidity in the non-critical cold areas.
Heating mats laying in the concrete door area
The heating mats should be laid in the door area (See pic.) into the floor level concrete slab at the depth of about 4 cm. The cables of the floor heating mat and of the temperature sensor must be connected to the control panel. Lay the connecting cables in this manner can avoid the damage, when the door and the door-post are installed.