R410a DC Inverter 60Hz Carrier service manual
Selection Procedure
2. Unit Selection (Based on cooling load)
2.1 Given condition
2.1.1 Design condition (Cooling: Indoor 20°C (WB), Outdoor 35°C (DB))
2.1.2 Cooling load
Location
Room A Room B Room C Room D
Room E
Room F
Load Btu/h(kW) 7170(2.1) 9559(2.8) 11900(3.5) 15700(4.6) 19790(5.8) 24570(7.2)
2.1.3 Pipe length: 164ft(50m)
2.1.4 Height difference: 98.4ft( 30m)
2.2 Indoor unit selection
Select the suitable capacity for condition of ‘Indoor 20°C (WB), Outdoor 35°C (DB) using indoor unit
capacity table. The selected result is as follows. (Assuming the indoor unit type is duct)
Location Room A Room B Room C Room D Room E Room F
Load Btu/h (kW) 7170(2.1) 9550(2.8) 11940(3.5) 15700(4.6) 19800(5.8) 24570(7.2)
Unit size 22 28 36 45 56 71
Capacity Btu/h (kW) 7850(2.3) 9900(2.9) 12600(3.7) 16400(4.8) 20500(6.0) 25600(7.5)
2.3 Outdoor unit selection
2.3.1 Assume the indoor unit and outdoor unit combination as follows
2.3.1.1 Calculate the total nominal capacity of indoor units in the combination according to the above table:
2.2 × 1 +2.8 × 1+ 3.6 × 1 +4.5 × 1+ 5.6 × 1 + 7.1 × 1 =88000Btu/h( 25.8kW)
2.3.1.2 Select outdoor unit: 38VF010H117010 which has nominal cooling capacity: 95500Btu/h (28kW)
Calculate the proportion between ① and ②: 88000/95500= 92%
2.3.2 Result : Because the proportion is within 50～130%, it is a ‘Right’ selection.
2.3.3 Real function data with indoor unit combination
● For the 92% combination, calculate the cooling capacity of outdoor unit (38VF010H117010).
90900Btu/h (26.65kW) ←90% (Indoor temperature: WB 68℉(20°C), Outdoor temperature: DB 95℉
(35°C) )
101000Btu/h (29.61kW) ←100%(Indoor temperature: WB 68℉(20°C), Outdoor temperature: DB 95℉
(35°C) )
Then calculated the outdoor capacity in 92% combination index:
Therefore: 90900+{(101000-90900)/10}×2=92900Btu/h (26.65+ {(29.61-26.65)/ 10} ×2= 27.24Kw);
● Outdoor unit (38VF010H117010) cooling temperature: DB 95℉(35°C)
● Capacity modification coefficient with pipe length 164ft (50m) and height difference 98.4ft (30m):
0.958
● Each indoor unit cooling capacity
42VD007H113003011: 92900 × 75100/88000 × 0.958 = 75952Btu/h (27.24 × 22/258 × 0.958 = 2.22(kW) )
42VD009H113003011: 92900 × 95500/88000 × 0.958 = 96600Btu/h (27.24 × 28/258 × 0.958 = 2.83(kW) )
42VD012H113003011: 92900 × 12300/88000 × 0.958 = 12400Btu/h (27.24 × 36/258 × 0.958 = 3.64(kW) )
42VD016H113003011: 92900 × 15400/88000 × 0.958 = 15500Btu/h (27.24 × 45/258 × 0.958 = 4.55(kW) )
42VD020H113003011: 92900 × 19110/88000 × 0.958 = 19300Btu/h (27.24 × 56/258 × 0.958 = 5.66(kW) )
42VD024H113003011: 92900 × 24200/88000 × 0.958 = 24500Btu/h (27.24 × 71/258 × 0.958 = 7.18(kW) )
Location Room A Room B Room C Room D Room E Room F
Load Btu/h (kW) 7170(2.1) 9550(2.8) 11940(3.5) 15700(4.6) 19800(5.8) 24570(7.2)
Unit size 22 28 36 45 56 71
Capacity Btu/h (kW) 7570(2.22) 9660(2.83) 12420(3.64) 15520(4.55) 19300(5.66) 24500(7.18)
2.4 Conclusion
Generally, we think this result is acceptable, so we we have accomplished the calculation. But if you think
this result is not acceptable, you can repeat the above process.
Remark: In this sample, we don’t consider other capacity modification indexes and assume them are 1.0.
For more details about the effect factor such as outside ambient/inside ambient DB/WD, please refer
to the performance table of indoor and outdoor units.
To Next Page
Loading...
