A Cooling evaporator in a fridge case with a design temperature of 5 Deg C. The Air off and Air on the fridge coil varies pending Ambient, Product, Product temperature/Mass etc. We have no control of what food product is being put in the fridge case but I need to calculate a Product Temperature Caluclation. How can I calculate the Product Temperature?
A Rule of thumb is 55% of the air off and 45 % of the air on but there would be a lag in the product temperature over a period of time particularly when the fridge goes on defrost.
So, if the case has a defrost cycle that lasts 30 minutes and terminates at 12 Deg C and then goes back to cooling, the Air on and Air off temperatures would rise considerably however the product temperature would not necessarily rise to these levels Example Air 0ff Temp 1 Deg C Air on Temp 7 Deg C. CPT = 0.55 + 3.15 = 3.7 Deg C + Defrost Factor + Time factor?