# Conversion Factors

Multiply | By | To Obtain | |

Atmosphere | 29.92 | Inches of mercury | |

Atmosphere | 33.92 | Feet of water | |

Atmosphere | 14.7 | Pounds per sqare inch | |

Atmosphere | 1.058 | Tons per square foot | |

Barrels (oil) | 42 | Gallons | |

Boiler Horsepower | 33,474 | Btu per hour | |

Boiler Horsepower | 34.5 | Pounds water evaporated from and at 212F | |

BTU | 778 | Foot-Pounds | |

BTU | 0.000393 | Hoursepower-hours | |

BTU | 0.000293 | Kilowatts-hours | |

BTU | 0.0010307 | Pounds water evaporated from and at 212F | |

BTU per 24 hr | 0.00000347 | Tons of referigeration | |

BTU per hour | 0.00002986 | Boiler horsepower | |

BTU per hour | 0.000393 | Horsepower | |

BTU per hour | 0.000293 | Kilowatts | |

BTU per inch per sq. ft. per hour per F | 0.0833 | Btu per foot per sq. ft. per hour per F | |

Cubic feet | 1,728 | Cubic Inches | |

Cubic feet | 7.48052 | Gallons | |

Cubic feet of water | 62.37 | Pounds at (at 60F) | |

Cubic feet per minute | 0.1247 | Gallons per second | |

Feet of water | 0.881 | Inches of mercury (at 32F) | |

Feet of water | 62.37 | Pounds per square foot | |

Feet of water | 0.4335 | Pounds per square inch | |

Feet of water | 0.0295 | Atmospheres | |

Feet per minute | 0.01136 | Miles per hour | |

Feet per minute | 0.01667 | Feet per second | |

Foot-pounds | 0.001286 | Btu | |

Gallons (U.S.) | 0.1337 | Cubic feet | |

Gallons (U.S.) | 231 | Cubic inches | |

Gallons of water | 8.3453 | Pounds of water (at 60F) | |

Horsepower | 550 | Foot pounds per sec | |

Horsepower | 33,000 | Foot-pounds per min | |

Horsepower | 2,546 | BTU per hour | |

Horsepower | 42.42 | BTU per minute | |

Horsepower | 0.7457 | Kilowats | |

Horsepower (boiler) | 33,475 | BTU per hour | |

Inches of mercury (at 62F) | 13.57 | In. of water (at 62F) | |

Inches of mercury (at 62F) | 1.131 | Ft. of water (at 62F) | |

Inches of mercury (at 62F) | 0.4912 | Pounds per sq in. | |

Inches of mercury (at 62F) | 70.73 | Pounds per sq ft. | |

Inches of water (at 62F) | 0.07355 | Inches of mercury | |

Inches of water (at 62F) | 0.03613 | Pounds per sq in. | |

Inches of water (at 62F) | 5.202 | Pounds per sq ft. | |

Inches of water (at 62F) | 0.002458 | Atmospheres | |

Kilowatts | 56.92 | BTU per minute | |

Kilowatts | 1.341 | Horsepower | |

Kilowatts-hours | 3,415 | BTU | |

Latent heat of ice | 143.33 | BTU per pound | |

Pounds | 7,000 | Grains | |

Pounds of water at 60F | 0.01602 | Cubic Feet | |

Pounds of water at 60F | 27.68 | Cubic Inches | |

Pounds of water at 60F | 0.1198 | Gallons | |

Pounds of water evaporated from and at 212F | 0.284 | Kilowatt-hours | |

Pounds of water evaporated from and at 212F | 0.381 | Horsepower-hours | |

Pounds of water evaporated from and at 212F | 970.4 | BTU | |

Pounds per square inch | 2.309 | Ft. of water (at 62F) | |

Pounds per square inch | 2.0416 | In. of mercury (at 62F) | |

Tons of refrigeration | 12,000 | BTU per hour | |

Tons of refrigeration | 200 | BTU per minute | |

Tons (Long) | 2,240 | Pounds | |

Tons (Short) | 2,000 | Pounds | |

Watts | 44.26 | Ft. pounds per min | |

Watts | 0.7378 | Ft. pounds per sec | |

Watts | 0.05692 | BTU per minute | |

Watt-hours | 3.415 | BTU | |

Watt-hours | 2,656 | Ft. pounds |

. | ||

EDR to Pounds of condensate per hour (Divide EDR by 4) • EDR to GPM (Multiply EDR by 0.0005) EDR to BTUH at 1 psig steam pressure (Mulitply EDR by 240) • EDR to boiler horsepower (Divide EDR by 140) EDR to Grate Area in Square Feet (Divide EDR by 196) • BTUH to EDR (Divide BTUH by 240) BTUH to Boiler Horsepower (Divide BTUH by 33,475) • PSIG to Feet of Water (Multiply PSIG by 2.31) Boiler Horsepower to Pounds of Condensate per hour (Multiply BHP by 34.5) • Boiler steaming rate (regardless of type or manufacturer) = 1/2 GPM per 1,000 sq. ft. EDR | ||

Fuel Values: | Maximum copper tubbing flow rates and BTUH loads (at 20° Δ T) | |

No. 1 fuel oil = 135,000 BTU per gallon | 1/2" = 1-1/2 GPM = 15,000 BTUH | |

No. 2 fuel oil = 140,000 BTU per gallon | 3/4" = 4 GPM = 40,000 BTUH | |

No. 4 fuel oil = 155,000 BTU per gallon | 1" = 8 GPM = 80,000 BTUH | |

No. 5 fuel oil = 150,000 BTU per gallon | 1-1/4" 14 GPM = 140,000 BTUH | |

No. 6 fuel oil = 153,000 BTU per gallon | 1-1/2" = 22 GPM = 220,000 BTUH | |

Natural gas = 1,000 BTU per cubic foot | 2" = 45 GPM = 450,000 BTUH | |

Natural gas = 100,000 BTU per Therm | ||

Manufactured gas = 550 BTU per cubic foot | ||

Propane = 2,250 BTU per cubic foot | Fahrenheit to Celsius = (°F - 32°) / 1.8 Celsius to Fahrenheit = °C x 1.8 + 32° | |

Propane = 92,000 BTU per gallon | ||

Electricity = 3,415 BTU per kWh | ||

Anthracite coal = 13,700 BTU per pound | Stream Fan Coil loads in Pounds of Steam per hour = | |

Bituminous coal = 12,500 BTU per pound | CFM X ΔT of air (in °F) / 800 | |

Wood = 14,000,000 BTU per mixed cord | ||

EDR FOR HOT WATER RADIATORS: | ||

Average water temp °F | Output in BTUH per sq ft. EDR | |

150 | 110 | |

155 | 120 | |

160 | 130 | |

165 | 140 | |

170 | 150 | |

175 | 160 | |

180 | 170 | |

185 | 180 | |

190 | 190 | |

195 | 200 | |

200 | 210 | |

205 | 220 | |

210 | 230 | |

215 | 240 | |

220 | 250 | |

*(also for 1 psi steam) | ||

Pump Head Rule of Thumb: | ||

Measure longest run in feet. Allow 6 feet of pump head per 100 feet | ||

(this includes an allowance for the fittings and the boiler) |