Power consumption in a walk-in freezer room

Hello,

I have been looking for an equation that helps me calculate the power consumption in a walk-in freezer at different temperature levels, but with no luck so far.

The freezer volume is 13x11x8 meters cubed. Temperature is set to -24 degrees Celsius and I need to find difference in power consumption if temperature was lowered to -18 degrees Celsius.

Also, how can I calculate the infiltration losses of a walk-in freezer room?

Mentioning a reference would be much appreciated.

Thanks in advance!

.

Power consumption can be calculated using a pH chart

See

http://www.en.ipu.dk/Indhold/refrige.../coolpack.aspx

Rob