Evporator Selection

[suny]

Dear Friends

I have a problem in selectingan evaporator coil for a fish storing cool room which maintains at -20 Deg C. Thecooling load is 14.4 kW/hr, Te -26 Deg C. The evaporator manufacture catalogue givesRefrigeration capacity 14.3 kW/hr @ 6KTD, Cooling surface 85 M³ with 3 x 450 W fans and defrost heater load of 12 kW.I am confident that if I select this, the FCU load, correction factor, KTDadjustment which needs for fish at 4, fans & heater loads are not accountedfor. Is it necessary for me to select a higher capacity evaporator taking intoconsideration all miscellaneous loads? Once adjusted to remove all miscellaneousheat loads discussed above needs a capacity of 29.8 kW @ 6KTD evaporator modeland finally it gives 15 kW/hr. Please give me an advice on this subject.

[Magoo]

establish a total refrigeration loading multiply by 24hours, and divide by 16 run hours per 24 hours, that will give you a refrigeration loading for evaporator and condensing unit. You are confusing yourself with numbers.
Loading summary is = product load + panel load + fan load + defrost load + infiltration load + lights + fork hoists + people + 10 % safety loading.

[suny]

Thank you very much for your advice. Chineese supplier says load calculation as per your's & mine is correct. But the Singaporian supplier says that I have to adjust KTD difference, Correction Factor & Gas Multifirer over and above the fans & defrost loads. Please give a sugession.

[Magoo]

Your selection at -26'C Te and design air on at -20'C is 6KTD, reducing to 4KTD will reduce evap capacity and smaller condensing unit. ( evap duty / 6 x 4 = new capacity ) The evap duty will be spec'd to a particular refigerant, manufacturers publish a correction factor list for different refrigerants.