Thermal Conductivity and Surface Heat Release Coefficient of Rubber and Plastic Insulation Materials

Rubber and plastic insulation materials, the lower the thermal conductivity, the more energy-saving?

Of course! The lower the thermal conductivity, the more energy-saving, and the lower the thermal conductivity, the better the thermal insulation effect, which is certainly no problem. However, what you don't know is that only under the condition of the same thickness, the lower the thermal conductivity of the material, the better the insulation effect will be. As we all know, the thermal conductivity of rubber and plastic Duquesne insulation material is lower than the thermal conductivity of glass wool, is it possible to say that 25mm rubber and plastic insulation material is more energy-efficient than 100mm thickness of glass wool.

For example, assuming a building with an air duct area of 10000 square meters, the air supply temperature of the air conditioner is 14 ℃, and the indoor design temperature is 26 ℃. At this temperature (the average temperature is 20 ℃), the thermal conductivity is 0.034W/(m k)

When using 19mm rubber insulation material, energy consumption q = 14.784W/m2 Q = 147.84kwH

When using 25mm rubber insulation material, energy consumption q = 11.725W/m2 Q = 117.25kwH

For 10000 square meters of air supply area of the air supply pipe insulation, the use of thicker insulation materials can save 30.59 degrees of electricity.

Rubber and plastic insulation materials as the main force of air conditioning system insulation, the major rubber and plastic insulation material suppliers are also developing foam materials with lower thermal conductivity, hoping to provide customers with more perfect solutions. Rubber and plastic thermal insulation materials are already the leaders in the thermal insulation industry due to their low thermal conductivity. The products of major material suppliers are not equal in thermal conductivity. The thermal conductivity of 0.034W/(m k) at normal temperature is almost the limit of rubber and plastic products. Even if it can be lower, the gap is only about 0.001W/(m k), let's take a look at the impact of this 0.001 on the energy saving of the whole system:

For example, assuming that the building has a duct area of 10000 square meters, the air supply temperature of the air conditioner is 14 ℃, the indoor design temperature is 26 ℃, and 19mm rubber and plastic insulation materials are used (the surface heat resistance coefficient is 8.5)

At this temperature (average temperature is 20 ℃)

When the thermal conductivity is 0.034W/(m k), the energy consumption q = 14.784W/m2 Q = 147.84kwH When the thermal conductivity is 0.033W/(m k), the energy consumption q = 14.423W/m2 Q = 144.23kwH

That is to say, for the air supply pipe insulation with an air supply area of 10000 square meters, using a lower thermal conductivity can save 3.61 degrees of electricity for one hour. The lower the thermal conductivity, the more energy-saving is certain. As for whether the energy-saving effect is really achieved, it is still up to the customer to judge. This is a secret that cannot be said.

Rubber and plastic insulation materials, whether to prefer insulation materials with higher surface heat release coefficient

For this problem, first of all, we need to find out why the air conditioning system insulation, is to prevent the pipeline to prevent condensation, is to prevent pipeline corrosion, is to ensure that the pipeline does not condensation conditions, saving material costs? The author believes that energy saving is the purpose, in the reasonable control of material costs at the same time, to achieve energy-saving effect is the customer approval of the program. Therefore, the thickness of condensation prevention as the insulation thickness of the air conditioning system will undoubtedly only consider the initial investment cost. As we mentioned earlier, the impact of material thickness on system energy saving cannot be ignored!

Then, what is the influence of the surface heat release coefficient of the insulation material on the thickness of the material? The surface heat protection coefficient α is the comprehensive value of the radiation heat transfer coefficient and the convection heat transfer coefficient, which is mainly affected by the surface color, gloss, roughness, ambient temperature and wind speed of the material. When the anti-condensation thickness is selected, the higher the heat release coefficient of the material surface, the smaller the required insulation thickness.

To sum up, then our problem can be solved, the surface heat coefficient is high and can not be used as the standard of high quality rubber and plastic insulation materials, of course, should not be preferred. The higher the surface heat protection coefficient of the insulation material, the smaller the required insulation thickness, and the less the amount of insulation material required, but the energy loss is large, which is a secret that cannot be said.