How to Select an Evaporator for a Commercial Cold Room
Fin Spacing or Fins Per Inch (FPI)
Fin spacing refers to the distance between each aluminum fin in the evaporator coil. This spacing is critical in determining air circulation and heat exchange efficiency. It is measured in millimeters (mm) or Fins Per Inch (FPI).
How to Choose the Right Fin Spacing?
The choice of fin spacing depends on the temperature and humidity levels in your cold room…
4.5mm Spacing (6 FPI or )
Ideal for environments with room temperatures of 5°C to 15°C, where frost is not a concern.
6.0mm Spacing (5 FPI)
Suitable for coolers with room temperatures around -2°C.
7.0mm Spacing (4 FPI)
Great for freezers operating around -18°C, minimizing frost build-up.
10.0mm Spacing (2 FPI)
Designed for very low-temperature environments like blast freezers, down to -45°C.
Why is Fin Spacing Important?
Fin spacing impacts air circulation and defrosting performance. A lower FPI (wider spacing) is preferred in freezers to prevent icing, while a higher FPI (narrower spacing) is more suited for chillers where fast heat exchange is needed.
Finding Your Edge When Selecting an Evaporator
Most suppliers offer stock evaporators with 7mm fin spacing (4 FPI), which can operate across a broad temperature range from 15°C to -18°C. However, for higher-temperature applications (e.g., 5°C to 15°C), selecting an evaporator with 4mm fin spacing can be more cost-effective. These smaller evaporators offer similar capacities but at a lower cost.
Key takeaway
Always check the fin spacing when selecting an evaporator. It plays a critical role in determining both performance and cost efficiency for your refrigeration system.