Heat Gain from Electrical Motors in Continuous Operation

Heat transferred from electrical motors to rooms with different locations of fan and motor

Electrical motors in air condition system contributes to the heat loads in air condition systems and have influence on the cooling equipment dimensions.

Gained heat load from electrical motor and fans in different locations can be estimated from the table below:

Shaft Output (kW)	Full LoadElectrical Motor Efficiency- η - (%)	Electrical Motor Input (kW)	Location of Fan and Motor
			1 Motor and Fan in the Inlet Air Flow or in the Room (kW)	2 Motor Outside the Air Flow or Outside the Room. The Fan in the Inlet Air Flow or in the Room (kW)	3 Motor in the Room. The Fan in the Outlet Air Flow (kW)
0.05	40	0.13	0.13	0.05	0.08
0.07	46	0.15	0.15	0.07	0.08
0.10	55	0.18	0.18	0.10	0.08
0.14	60	0.23	0.23	0.14	0.09
0.20	64	0.31	0.31	0.20	0.11
0.28	66	0.42	0.42	0.28	0.14
0.40	70	0.60	0.60	0.40	0.20
0.56	72	0.78	0.78	0.56	0.22
0.80	76	1.05	1.05	0.80	0.25
1.1	80	1.38	1.38	1.1	0.28
1.6	80	2.0	2.0	1.6	0.40
2.5	81	3.1	3.1	2.5	0.60
4.0	82	4.9	4.9	4.0	0.90
5.6	84	6.7	6.7	5.6	1.1
8.0	84	9.5	9.5	8.0	1.5
11.2	86	13.0	13.0	11.2	1.8
16	87	18.4	18.4	16	2.4
20	88	22.7	22.7	20	2.7
25	89	28.0	28.0	25	3.0
32	89	36.0	36.0	32	4.0
40	89	45.0	45.0	40	5.0
50	90	56.0	56.0	50	6.0
63	90	70.0	70.0	63	7.0
80	90	89.0	89.0	80	9.0
100	91	110	110	100	10.0

• 1 kW = 1,000 Watts = 3,412 Btu/h = 737.6/550 British hp = 1.341 British hp = 10³/9.80665 kg_f m/s = 737.6 ft lb_f/s = 10³/(9.80665 75) metric hp