With coming of the cold weather we get increasing complaints about the condensation on the inner surface of the front door. Detailed analysis of the situation has revealed a number of violations operating rules that are common and have become a standard. It is impossible to neglect the laws of physics.
Metal door has a level of thermal resistance that is lower than the level of thermal resistance of the brick or block walls. This difference is based on thermal conductivity of materials as well as on the thickness of the wall and thickness of metal of the entrance door.
The second factor influencing the occurrence of condensation on the surface of the door is a difference in temperature. In the winter time cold can reach up to -30 ° C and even higher. Therefore, the difference between the outside and the inside temperature can be 40-45 ° C, sometimes 50 ° C.
Note that the condensation on the inner surface of the door depends on the level of humidity and difference in the air temperature. The larger the difference, the larger is appearance of condensation of the surface. Such physical process is called "Point of Dew" and is determined by special scales. As an example, when the room temperature is 22 ° C and 50% humidity, condensation will appear on the surface of a metal door when the temperature outside will be 11.1 ° C.
To sumit up, the formation of condensation on the inside surface of the door in the autumn-winter period under certain temperature and humidity is inevitable. However, understanding the essence of the processes, it is possible to significantly reduce the condensation. You can find tips and helpful advice on the subject in the answer to the question "How to get rid of condensation on the inner surface of the front door?"