The Research Of Insulation Design Criteria And National Standard

Air-conditioning system supplies heating or cooling energy for indoor environment by high or low temperature media, so it is important to insulate the pipeline to avoid too much energy loss. By now, we can almost say that insulation design and engineering application have been growing mature. But we discover many errors in the popularly used standards.Insulation technology has been used a wide range of fields. It is not only often used in architecture but also in the manufacturing and other industry, particularly in the chemistry and electricity power industry. The author discover that the editors of the published insulation standards mostly belong to chemistry or power circle., So the insulation theory and formula are basically for the chemistry and electricity pipelining, and the heating or cooling transporting media are all materials with high surface heat-exchange coefficient such as water, oil and vapor, etc. For these materials, the inside surface heat-exchange coefficient is so small that can be neglected in the insulation thickness calculation. However, when it comes to the air-duct insulation thickness calculation in the HVAC engineering, the inside surface heat-exchange coefficient can not be omitted due to the physical character of the air, which has a very similarly equal inside and outside surface heat-exchange coefficient. So, it will definitely leads to errors when using the insulation thickness formula for the air-duct. This is the most serious problem confronting the HVAC engineers. These problems are some technical demands such as the design temperature of the outside surface of the insulation layer, the environment temperature of outdoor, etc.The characters and technical data have been interpreted in detail in the insulation design standard. After further research, the author find that the technical data of some materials are not optimize, or ever wrong.These existed problems maybe not serious enough to endanger the whole HVAC system or insulation blocks, and even maybe it will not greatly increase the first cost or affect the insulation effect. But these problems should not be remained unnoticed for a long tern. This article will one by one bring out the error or uncertified items in the national insulation standards, aiming to get the associating people noticing the problems.