Room temeperature calculations

[nanuuk]

Can anyone tell me where I can find calculations on costing for cold rooms. I have a customer that wants to store Tuna in one of our rooms. We currently keep the room at -4F the customer wants to have the room brought down to -7.5F. Assuming the product will be coming in at that temp what would the cost be per Kwh. The room is quite large 2144 pallet positions.

[cadwaladr]

Over here we have companies that store in cold stores the cost could be found out by making calls to people who do the same in your vicinity albeit in disguise the main cost i think is the putting it in and taking it out its called r+d i think so if they store it a cost applys but taking it in and out burdens extra cost to you client and good notice has to be given with release documents etc,hope my content helps you in a small way

[NH3LVR]

You need to be more specific here about what you are asking.
Is the question how much more power it will take to hold the room at -7.5F, rather than -4F?
If this is what you want to determine it can be complicated. (for instance, will the head pressure rise?) Will another compresser have to be brought on line?
The cost of a Kwh is determined by your power supplier.

[RANGER1]

What brand, type & size of compressor do you have on low & high side?
What are suction & interstage conditions at the moment.

2 degC lower room temps not that significant, but compressor will have to run probably 2 deg C lower suction pressure of course which can effect plant because of other rooms running higher temperature.

[Segei]

At lower room temperature your heat load will increase. Assume that annual mean temperature in your area is 50F. Lowering room temperature by 3.5F will increase load and energy use by 7%. Additional energy use will come from lowering suction pressure 3-5%. Total energy use will increase by 10-12% at assumption that product comes at room temperature.