When working out the product load for a freezer is the following method correct-

(SA x TD) + L + (SB X TD) x PW
PD X 3.6
Where-
SA = sensible heat above freezing
TD = Temperature above/below freezing
L= LAtente heat
SB= sensible below freezing
PW= product weight
PD = pull down period of product in hours

By my recall the top line give me the load in kj/kg and by dividing it by the time give me an answer in watts.

Please any information is greatly appreciated.