For data center air conditioning systems (especially precision air conditioners or CRAC units), the vacuum level requirement mainly depends on whether the system has a compressor (with refrigerant) and the manufacturer’s specifications. Here are the industry-standard guidelines:
Target vacuum level:
500 microns or lower (≈0.66 mbar, ≈66 Pa)
This is the common HVAC and data center standard to ensure the system is almost free of moisture and air.
High Standard / Best Practice:
300 microns or lower
Recommended for large refrigeration systems or those sensitive to moisture (e.g., low-temperature systems, long piping).
A refrigeration system must be free of moisture and air; otherwise, it can cause:
Freeze-up (ice blockages)
Acid formation leading to compressor damage
Reduced heat transfer efficiency
Below 500 microns means the system pressure is close to a true vacuum, and most residual moisture has been removed.
Pull down to about 1500 microns first, hold for a few minutes to check for leaks.
Then pull down to 500 microns or lower, and hold for 10–15 minutes without rising.
If the pressure rises quickly after stopping the pump, there’s likely a leak or residual moisture.
在数据中心空调（尤其是精密空调或CRAC系统）安装和维护过程中，抽真空的标准主要取决于系统中是否有压缩机（带制冷剂）以及厂商规范。以下是行业通用标准：
目标真空度：
500 micron 或更低（≈0.66 mbar，≈66 Pa）
这是绝大多数 HVAC 和数据中心空调行业的通用标准，确保系统内部接近无水分和无空气。
高标准/最佳实践：
300 micron 或更低
用于大型制冷系统或对湿气敏感的系统（如低温系统、长管路系统）。
制冷剂系统必须确保内部没有水分和空气，否则会导致：
冻结堵塞（冰堵）
酸性物质腐蚀压缩机
降低换热效率
500 micron 以下表示系统压力已经非常接近真空状态，残余水分基本被蒸发带走。
先抽到 1500 micron，保持几分钟，确认泄漏。
再抽到 500 micron 或更低，并保持 10~15 分钟稳定（不回升）。
如果停泵后上升速度快，说明有泄漏或水分未完全去除。
Malaysia
