HVAC Presentation-3 Power

HVAC

• Concept of system from CAD file, with all details.• How to choose chillers?• Explain the control of chillers• Choose A.H.U. or F.C.U according to what?• How to choose A.H.U?• Explain the control of A.H.U.• Distribution of air and water at a certain level.• Electrical switch boards and bus bar.

HVAC• Concept of system from CAD file, with all details.• How to choose chillers?• Explain the control of chillers• Choose A.H.U. or F.C.U according to what?• How to choose A.H.U?• Explain the control of A.H.U.• Distribution of air and water at a certain level.• Electrical switch boards and bus bar.


• Calculations steps:

• Compute area & volume.

• BTU/hr= (300 or 350) * volume.(350 for places that have large amount of heat generation such as gymnasium).

• Cooling capacity in KW = BTU/hr * 3.5/12000

• Example:

• Total cooling capacity for level 13 is 117 KW

• Total cooling capacity for all building is 2751 KW

• Physical data:

• Taking diversity factor =0.8

• electrical data:

• From electrical data table:

• 3 units of 30HXC230 each unit has input power of 164 KW and 294 A input current.

• The total Chiller current: 882 A

• Cables from EL SEWEDY catalogue: Multi-core cables, with standard copper conductors PVC insulated and PVC sheathed, Multi-core with reduced neutral.



• Operation of AHU:

• AHU is used for areas more than 30 and it has 2 inputs “fresh air controlled by damper, input filter and the other input is cooling water comes from chiller”.

• The cooling water enters circulating duct, fresh air touches this duct from the outside to lose its temperature, then it reaches to all the places by ducts and grills.

• Output of the AHU is a hot water which is the input of the chiller

• Operation of FCU

• FCU depends on circulate the air in room

• FCU Used for small area less than 30 , or places of low popularity.


• Steps of calculation:

• calculate flow rate of the hotel by (L/S) for areas more than 30 ,

• Flow rate=

• The fresh air of AHU will distribute in places through ducts

• Calculation of ducts size using duct sizer program

• Ex. Total floor flow rate= 5037 L/S Total building flow rate= 1339200 L/S

• AHU has the following rating

• Type A 1000 66000 m3/hr• Type B 1000 17000 m3/hr• Type C 1000 6000 m3/hr• Type D 50,000 130,000 m3/hr• Type E 300 2300 m3/hr

• Using 4 units of AHU with rating = 50,000 130,000 m3/hr, each unit loaded by 93,000 m3/hr, so each unit feeds 9 levels by air conditioning.

• AHU has the following rating

• Type A 1000 66000 m3/hr• Type B 1000 17000 m3/hr• Type C 1000 6000 m3/hr• Type D 50,000 130,000 m3/hr• Type E 300 2300 m3/hr

• Using 4 units of AHU with rating = 50,000 130,000 m3/hr, each unit loaded by 93,000 m3/hr, so each unit feeds 9 levels by air conditioning.




• Each AHU consumes 10KW, • Current = = 18A,

• Each FCU consumes 1A

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HVAC Presentation-3 Power