Conversion Factors

1- Speed of Sound in Air

1128.5 Ft./Sec. = 769.4 MPH

2- Pressure

14.7 psi = 33.95 Ft. H2O = 29.92 In. Hg = 407.2 In.W.G. = 2116.8 Lbs./Sq.Ft.

1 psi = 2.307 Ft. H2O = 2.036 In. Hg = 16 ounces = 27.7 In.WC

1 Ft. H2O = 0.4335 psi = 62.43 Lbs./Sq.Ft.

1 Ounce = 1.73 In.WC

3- Density

A. Water:

62.43 Lbs./Cu.Ft. = 8.33 Lbs./Gal. = 0.1337 Cu.Ft./Gal.

1 Cu.Ft. = 7.48052 Gallons = 29.92 Quarts = 62.43 Lbs. H2O

B. Standard Air @ 60°F., 14.7 psi:

13.329 Cu.Ft./Lb. = 0.0750 Lbs./Cu.Ft.

1 Lb./Cu.Ft. = 177.72 Cu.Ft./Lbs.

1 Cu. Ft./Lb. = 0.00563 Lbs./Cu.Ft.

1 Kg/Cu M = 16.017 Lbs./Cu.Ft.

1 Cu M/Kg = 0.0624 Cu.Ft./Lb

4- Energy

1 Hp = 0.746 KW = 746 Watts = 2,545 Btuh ≈ 1.0 KVA

1 KW = 1,000 Watts = 3,413 Btuh = 1.341 Hp

1 Watt = 3.413 Btuh

1 Ton Ac = 12,000 Btuh Cooling = 15,000 Btuh Heat Rejection

1 Btuh = 1 Btu/Hr.

1 BHP = 34,500 Btuh (33,472 Btuh) = 34.5 Lb.Stm/Hr. = 34.5 Lb.H2O/Hr. = 0.069 GPM =

4.14 GPH = 140 EDR (Sq.Ft. of Equivalent Radiation)

1 Therm = 100,000 Btuh

1 MBH = 1,000 Btuh

1 Lb.Stm/Hr. = 0.002 GPM

1 GPM = 500 Lbs.Stm/Hr.

EDR = Equivalent Direct Radiation

1 EDR = 0.000496 GPM = 0.25 Lbs.Stm.Cond./Hr.

1000 EDR = 0.496 GPM

1 EDR Hot Water = 150 Btu/Hr.

1 EDR Steam = 240 Btu/Hr.

1 EDR = 240 Btu/Hr. (Up to 1,000 Ft. Above Sea Level)

1 EDR = 230 Btu/Hr. (1,000 Ft.–3,000 Ft. Above Sea Level)

1 EDR = 223 Btu/Hr. (3,000 Ft.–5,000 Ft. Above Sea Level)

1 EDR = 216 Btu/Hr. (5,000 Ft.–7,000 Ft. Above Sea Level)

1 EDR = 209 Btu/Hr. (7,000 Ft.–10,000 Ft. Above Sea Level)

5- Flow

1 mgd (million gal./day) = 1.547 Cu.Ft./Sec. = 694.4 GPM

1 Cu.Ft./Min. = 62.43 Lbs. H2O/Min. = 448.8 GPH

6- HVAC Metric Conversions

KJ/Hr = Btu/Hr × 1.055

CMM = CFM × 0.02832

LPM = GPM × 3.785

KJ/Lb. = Btu/Lb. × 2.326

Meters = Feet × 0.3048

Sq.Meters = Sq. Feet × 0.0929

Cu.Meters = Cu. Feet × 0.02832

Kg = Pounds × 0.4536

1.0 GPM = 500 Lb Steam/Hr

1.0 Lb.Stm/Hr = 0.002 GPM

1.0 Lb.H2O/Hr = 1.0 Lbs. Steam/Hr

Kg/Cu.Meter = Pounds/Cu.Ft. × 16.017 (Density)

Cu.Meters/Kg = Cu.Ft./Pound × 0.0624 (Specific Volume)

Kg H2O/Kg DA = Gr H2O/Lb. DA/7,000 = Lb.H2O/Lb DA