The operation cost of cold storage is a large part of total cost. Electricity is the main power of cold storage and also the main cost. The energy-saving performance of cold storage is directly related to the ROE of the cold storage. ECOOL will introduce some energy saving technologies and measures in this article.
Nowadays, the most common used insulation product is polyurethane sandwich panel (Abbreviation PU or PUR panel). PUR panel has obvious advantages than EPS panel (Polystyrene) which was commonly used ten years ago, although some countries are still use them.
When select panels, please noticed the difference of manual product (PU panel) and machine product panel (PUR panel) because machine produced panel is evenly foamed and has better performance. PU panel’s density is around 38Kg/M3, while PUR panel could reach 40KG/M3. Among which, PIR panel(polyisocyanurate) are the best, with a density of 45Kg/M3.
Normally, the thicker the insulation layer, the better the performance. However, the cost is higher too. Where is the balance point? If you want too build a energy-saving cold storage, ECOOL suggest you choose the panel with 25% thicker than standard thickness. For example, cold storage around 0C usually use the 100mm thick insulation panel, choose 120mm thick insulation panel as the outside wall and ceiling panels will save the power consumption of equipment a lot. Usually, the extra cost could be covered in the 2 or 3 years of operation.
When there is big temperature difference between the inside and outside of cold rooms, the water in air of the high temperature side will condensate in the insulation layer of low temperature side. Condensation water will damp the insulation layer and affect their performance.
Normally, the moisture-proof layer is placed in the high-temperature side, ECOOL suggest moisture-proof layers on both sides
The cold bridge will affect the integrity of moisture-proof layer, it also increases the heat load of building, if the cold bridges are exposure in the air directly. So in the first design of cold storage, avoiding the cold bridges are very important. If it is unviable, choose the materials with smaller Thermal Conductivity.
Every time the cold room door open, the cold will be release and lead to the restart of refrigeration compressor. To reduce the cold loss, cold room door could use PVC door curtain. But for the doors which have forklift going through often, air curtain might be a better choice. Because the PVC curtain has the risk to hook on the products of forklift.
If possible, PVC curtain plus air curtain is the best.
For the door for a close loading area,
The other measure is to reduce the direct sunlight.
For example, to reduce the general surface area of cold storage when the total volume could reach the requirement;
If there is option, place the docking area in the non-direct sunlight side;
Use light color for the surface materials, such as white, grey white panels.
Use insulation materials such as glass wool between the roof panel and ceiling panel;
Keep good air circulation between the ceiling and roof;
To be continue…
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