Thermal bridge treatment
Introduction
The concept of thermal load is associated with air conditioning systems (heating and cooling), as well as refrigeration systems. This is the amount of thermal energy per unit of time (thermal power) that a closed room exchanges with the outside due to the different hygrothermal conditions inside and outside, considering the outside ones as the most unfavorable possible. The calculation of these loads makes it possible to arrange the appropriate heating or cooling systems to compensate them.
thermal loads
Thermal loads can be due to two stresses:
Thermal loads are due to various heat exchange phenomena between the building and the outside, as well as internal heat gains (in the warm season):
There are certain phenomena that are not taken into account in the calculation of winter conditions, since they improve the interior conditions in that season (sunlight, occupancy...), but that are important in summer conditions since they provide heat to the premises from the inside; in winter, the indoor environment control systems will take them into consideration. Thus, winter loads only depend on outdoor conditions, and summer loads depend on both indoor and outdoor conditions.
Determination of parameters
Interior conditions
The regulations of most countries set limit values for the conditions inside the enclosures. These limits are determined on the one hand by the comfort of the users and on the other hand by the necessary energy savings. Depending on the loads on the temperature difference between the outside and the inside, the smaller the difference, the lower the thermal loads will be.
Exterior conditions
Also in this case, regulations usually give calculation temperatures obtained from meteorological data taken over a series of years.
The way they are given varies from one country to another. In some, climatic zones are given through maps, setting a calculation temperature for each of them. In others they are given for each specific locality, sometimes with an adjustment table of these temperatures for smaller localities (generally without a meteorological observatory) depending on the difference in altitude with respect to sea level, of the locality with an observatory. In general, only temperatures are given and not relative humidity.