What is Thermal Bridge? How can it be prevented?
Heat transfer is from the high-energy (hot) side to the low-energy (cold) side. For this reason, contrary to general belief, cold store insulations are made and realized in the manner that heat would not enter from outside, not for the purpose of cold air inside not to escape.
Heat transfer is defined as the energy transfer between two or more objects with different temperatures through transmission, transport or radiation (or through the combination of these with each other). Basically, heat transfer through transport results from the movement of molecules in masses. The fluid like action between the surfaces at two different temperatures causes the heat transfer during this movement.
Heat transfer through transmission takes place in a stagnant environment. Heat is transferred to the next molecule by means of the vibrations in the cage-like structure of the molecules. The characteristic of the heat bridge regarding Cold Storage Doors is “heat transfer through transmission”.
Heat transfer through transmission takes place through substances or materials having different insulation characteristics and f heat absorption capacities. These materials which make up the “heat bridge” as a technical term causes heat energy transfer which could not be recognized with a naked-eye. Heat bridges could only be detected by thermal cameras. Thermal cameras catch up infrared rays which we cannot perceive with our eyes and convert these to values we can see on its screen.
Heat bridges transfer heat to the low-temperature environment that we are trying to maintain and increase our energy costs. So, since our cooling devices overwork, we come up against high electricity bills (unwittingly).
In addition to the ground, ceiling and lateral facades which separate the internal and external environment from each other, especially the heat bridges of the door system should also be broken. The heat bridges of other components of the cold storage such as stabilizer screw used, pipe and ventilation systems which transfer air or fluid (liquid) between the internal and external environment should also be broken. Otherwise, energy losses in the way of sweating and icing on materials and surfaces would occur. As icing is an indicator of energy loss, it is also a phase that inhibits the functioning of mechanical parts.
Basically, to cut the connection between the materials that transfer heat eliminates or minimizes this heat transmission. Generally, to cut the connection of the metal and various alloys which is the basic heat bridge due to heat absorption capacity with the ones placed in the internal and external environment is the easiest way to break the heat bridge.
We should consider two basic components when examining the heat bridge issue concerning the door. First one and the most efficient component is the doorframe. If you don’t have an application that would break the heat bridge between the doorframe that falls inside and outside the environment, the heat losses you will be exposed to unwittingly would be most of the time even higher than the actual cost of the door. When we consider the high cooling costs of especially shock and frozen rooms, we would more clearly understand the necessity of solving the heat bridge issue sensitively. However the type of material of the doorframe (stainless steel, aluminium or PVC), the contact between the surfaces and the internal and external environments should be absolutely isolated from each other. (See. PFI frame options)
The second component is the door blade. The contact between the aluminium profile (which surrounds the door blade) and inner surface sheet should be absolutely prevented. Moreover, the accessories on the blade to be designed in a way that prevent the heat transfer between the internal and external environments which is very important.
In light of all this information; we have solved the heat bridge concept technically and we are putting special emphasis on this matter in all our relevant products and applications as PFI. Our solutions regarding thermo-insulating cold storage doors are being followed by many manufacturing companies.
Based upon the requests of our customers, we are making thermal camera analyses of the current door systems and we are informing the project owners. We are helping to reduce the energy losses of our customers through suitable solution offers.
The thermal reflection on the top-left belongs to the picture on the bottom-right. Here there is an assembly fault which cannot be captured with a naked-eye. Although there isn’t any thermal problem regarding the door, the assembly fault has resulted in energy losses.
If you have any request relating to this matter, please contact PFI İstanbul Office. This analysis’s are not just for our current and potential customers, but also for raising awareness in our sector, and within the scope of our social responsibility, for all institutions that want to improve their knowledge regarding Thermal Bridge.