What are the types of insulation materials?

Standardized materials such as rock wool and glass wool, commonly used for insulation, are subject to national standards. Thermal conductivity, fire resistance tests, and heat loss are typically required to be tested and meet standards by the inspection department before being permitted for supply in the construction industry.

Prior to the 1980s, commonly used thermal insulation materials for cold storage included rice hulls, cork, slag, and expanded perlite. After the 1980s, the development of new insulation materials surged, with rock wool, glass wool, expanded polystyrene (EPS, XPS), and polyurethane foam plastics becoming increasingly popular, along with a variety of construction methods. Currently, the widely used materials for cold storage insulation include expanded polystyrene, extruded polystyrene, and polyurethane foam plastics.

2. The insulated design of cold storage primarily aims to prevent external heat from seeping into the cold storage. Besides the refrigeration system design, the insulation design is crucial for the cold storage. The heat transfer through the cold storage's envelope and insulation accounts for 20% to 35% of the total heat load. Therefore, reducing the heat load on the envelope can achieve energy-saving goals. The cold storage's consumption of cooling energy through the envelope is directly proportional to the unit heat flux of the envelope. To lower the unit heat flux, one should either choose insulation materials with a lower thermal conductivity or increase the thickness of the insulation layer. However, the thickness should not be excessively high, as this would increase construction costs and reduce usable space. Thus, it is essential to select insulation materials within an appropriate thickness range.

How to Use Insulating Materials

The optimization of the cold storage thermal insulation design involves not only material selection but also the critical determination of insulation thickness for preventing heat conduction. The thermal load of the protective structure is inversely proportional to the thickness of the insulation layer; increasing the insulation thickness reduces the operating costs of the cold storage but also increases the initial investment. Therefore, the economic thickness should be determined based on the cold storage's service life during construction. The economic thickness refers to the insulation layer thickness that minimizes the sum of initial investment in insulation, monthly operational management costs, and food dry loss costs to achieve economic benefits. When the condensation prevention thickness is greater than the economic thickness, the condensation prevention thickness is used as the refrigeration thickness. Conversely, if the economic thickness is greater than the condensation prevention thickness, the economic thickness is chosen as the refrigeration thickness.

2. The architectural style of cold storage, the selection of insulation materials, and their thickness play a crucial role in initial investment costs and long-term returns. While inexpensive materials can reduce initial investment, the choice of materials can bring greater long-term operational benefits. In today's era of promoting energy conservation and emission reduction, energy efficiency has become a theme of social development, and constructing energy-saving cold storage has become the direction of the cold storage industry.