i was assigned from my teacher to design a building with 48 floors and i have no idea what to do because all he gave me is these informations,



· Problem statement
Design the chilled water air conditioning system with heat exchanger and pumping system of the chilled water side of the system.
· Identification of customer need
§ Each floor need cooling capacity of 75 ton(900,000 BTUH).
§ Chilled water capacity be 2.4GPM for 1 refrigeration ton.
§ The chilled water temperature shall be 44-54degree fahrenheit.
§ Pressure drop on the air handling unit or fancoil unit shall be no more than 15 ft WG.
· Problem defination
§ Building with 48 storeys of 3.5 meter height.
§ Each floor has an area of 1350 square meter.
§ Each floor has core area 140 square meter.
§ Total using area each floor has 1350 square meter.
§ Basement floor of 1200 square meter with 4.5 meter height excluding the 48 storeys for using as the back of the house.
§ Specify all necessary accessories needs for th system such as valves,strainer,check valves , control valves,expansion tank and /or balancing valves.



so far now i've designed my piping system, AHU and now i have some problems with choosing what refrigerant should be used in this building.

It would be great if some of you can give me differences between each refrigerant that are commonly used in present.

Thx for every answer and sorry for my poor English.