Power; Work/Energy - Honeywell AUTOMATIC CONTROL SI Edition Engineering Manual

POWER

British
Thermal
Unit/Hour
Existing Unit (Btuh)
British Thermal —
Unit/Hour (btuh)
British Thermal 60
Unit/Minute
(Btu/min)
Foot 0.07716
Pounds/Minute
(ft-lb/min)
Foot 4.626
Pounds/Second
(ft-lb/s)
Horsepower (hp) 2546.4
Boiler 33520
Horsepower
(hp boiler)
Tons of 12000
Refrigeration
Kilowatts (kW) 3414.2
EXAMPLE:
15,000 Btuh x 0.0002929 = 4.3935 kW

WORK/ENERGY

Table 14. Work/Energy Conversion Multipliers. Energy/Work Conversion Multipliers
British Thermal
Existing Unit
British Thermal Unit
(Btuh) (15.6C)
Watt-hour (Wh)
Kilowatt-hour (kWh)
Calorie (Cal)
a
Foot-pound (ft-lb)
Joule (J)
Therm = a quantity of gas containing 100 000 Btu.
a
A foot-pound (ft-lb) is the I-P unit of work or mechanical energy which has the potential to do work. One ft-lb is the work
required to raise a weight of one pound one foot or the potential energy possessed by that weight after being raised in
reference to its former position. See TORQUE for pound-foot.
EXAMPLE:
45 Btu x 252 = 11,340 calories
ENGINEERING MANUAL OF AUTOMATIC CONTROL
Table 13. Power Conversion Multipliers.
British Foot
Thermal Unit/ Pounds/
Minute Minute
(Btu/min) (ft-lb/min)
0.01667 12.96
— 776.2
0.001286 —
0.0771 60
42.44 33 000
558.7 433 880
200.0 155 640
56.92 44 260
Unit Watt-hour
(Btuh) (15.6C) (Wh)
— 0.2931
3.412 —
3412 1000
0.00397 0.001163
0.001286 0.0003765
0.0009479 0.0002778
GENERAL ENGINEERING DATA
Desired Unit
Foot
Pounds/ Horse-
Second power
(ft-lb/s) (hp) (hp boiler)
0.2162 0.00039 0.0000298
12.96 0.02356 0.00179
0.01667 0.00003 0.0000023
— 0.00182 0.000138
550 — 0.07605
7231 13.15
2594 4.715 0.358
737.6 1.341 0.1020
Desired Unit
Kilowatt-hour Calorie
(kWh) (Cal)
0.0002931 252
0.001 860
— 860 000
0.0000012 —
0.00000038 0.3241
0.0000003 0.2390
471
Boiler
Horse- Tons of
power Refrig - Kilo-watts
eration
0.000083 0.0002929
0.005 0.01757
0.0000064 0.0000226
0.000386 0.00136
0.2121 0.7457
— 2.793 9.803
— 3.516
0.2844
Foot-pound
a
(ft-lb) Joule (J)
778.2 1055
2656 3600
2 656 000 3 600 000
3.085
—
0.7393
(kW)
—
4.184
1.353
—