Expanding on what Larry posted:
* How well insulated is the Freezer? - walls, doors, ceiling, floor.
* Is the Refrigerant Ammonia or Freon?
* Is the Freezer large (+ 2000 square feet) or small?
* How high is the ceiling + what level of heat transfer can take place between the Freezer's ceiling and the Building's roof (are they very close to each other)?
* Are the Lighting Fixtures Freezer rated Fluorescents / HIDs, or simple Incandescents?
* Is the temperature -30°C or less?
* Is there a "Vestibule", or does the staff transfer stock directly from warm (ambient +30°C) areas, in bulk quantities?
* Are the door and floor heat tape strips self regulating + working properly?
and the most important questions...
* Is the Refrigeration System adequately sized for the area to be cooled?
* Is it working properly, or does it require some R&R,
* Are there any penetrations which need to be sealed?
* Is the integrity of the Refrigerant piping's insulation good?
* Does the staff leave doors open for extended periods of time?
If the environment is adequately sealed, the heat trace strips are not going "full throttle 24/7", the Refrigeration Assemblage has been / will be properly maintained, the Lighting Fixtures do not contribute excessive heat (other than what is required for Lamp Starting + Operation), and the staff does not prop open the door(s) for 10 minutes every hour, - and the Freezer is not really large, the Condenser(s) should cycle on for an hour at most.
The Evaporator(s) fans may run constantly - to de-ice the evap coils, or there may be other means to control evaporator coil icing (thermal defrost techniques).
These should be figured as an LCL.
I also agree with Larry's suggestion to monitor the load(s) for at least a 7 day period. Chart frequency of starts/stops, duration of running, time of day, day of week, ambient temp, etc.
Remember, the complete KW "Package" for this Freezer will include:
- The Condensing Pumps,
- The Evaporator fans ("Fan Coils),
- Heat strips in the floor + at the door (-20°C and below),
- Evap coil defrosting,
- Humidity / Condensation control,
and - Lighting.
Good luck.
Let me know if I missed the point you were going for, or if you have additional questions.
Scott
