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FORMULAS & CONVERSIONS San Antonio 4710 Perrin Creek #300 San Antonio, Texas 78217 Tel: 210.650.9005 Toll Free: 800.650.6507 Fax: 210.590.1645 www.mechreps.com Rio Grande Valley 1409 N. Stuart Place Road Suite E Harlingen, Texas 78552 Tel: 956.412.1110 Fax: 956.412.1350 www.mechreps.com Austin 3901 Woodbury Drive P.O. Box 41869 Austin, Texas 78704 Tel: 512.444.1835 Fax: 512.444.5522 www.mechreps.com CONVERSION FACTORS To Convert Feet of Water Feet of Water Gallons of Water Gallons of # 2 Oil Horsepower Horsepower Horsepower (boiler) BTU / Hr. Horsepower (boiler) Kilowatts Inches of Mercury Inches of Mercury Kilowatts Kilowatts Pounds of Water Pounds of Water Pounds/ Sq.Inch Therms of Gas Tons (refrigeration) BTU/ Hr. Watts Electrical Formulas To Find Single Phase MOTOR FULL-LOAD AMPERES Three-Phase AC Squirrel-Cage & Wound-Rotor Horse- power To Inches of Mercury Pounds/ Sq. Inch Pounds of Water BTU’s Kilowatts BTU / Hr. Multiply By 0.8826 0.4335 8.3452 140,000 0.7457 2545 33479 9.803 1.133 0.4912 3413 1000 0.01602 0.1198 2.307 100,000 12,000 3.413 Single Phase AC 208 V230 V460 V115 V200 V230 V 1/6 1/4 1/2 3/4 1 1.5 2 3 5 7.5 10 15 20 25 30 40 50 60 75 100 273 125 342 150 200 4.4 5.8 9.8 2.5 3.3 5.6 7.9 9.2 11.5 13.8 19.6 32.2 46 2.2 2.9 4.9 6.9 8 10 12 17 28 40 50 2.3 3.2 4.1 5.7 7.5 11 16.715.2 24 31 46 59 75 88 114 143 170 211 2 2.8 3.6 5.2 6.8 9.6 1 1.413.8 1.8 2.6 3.4 4.8 7.6 11 14 21 27 34 40 52 65 77 96 124 156 180 240 16 20 24 34 56 80 10057.5 Feet of Water Pounds/ Sq. Inch BTU/ Hr. Watts Cubic Feet Gallons Feet of Water BTU’s 22 28 42 54 68 80 104 130 154 192 248 312 360 480 BTU/ Hr. Two Phase-Four Wire Three Phase Amps when “HP” is known V x %EFF x PF V x %EFF x PF x 1.73 HP x 746 HP x 746 V x %EFF x PF x 2 HP x 746 396 528 ?????????????????????????? ? Amps when “KW”is known Basic Fan Laws Variation Volume KW x 1000 V x PF KW x 1000 V x PF x 2 KW x 1000 V x PF x 1.73 ? ??????????? ? ? ?????????????????????? ? Density Change Fan Speed Change Amps when “kVA”is known Varies Directly with Speed Ratio ( Varies with SQUARE of Speed Ratio ( Varies with CUBE of Speed Ratio ( kVA x 1000 V kVA x 1000 V x 2 kVA x 1000 V x 1.73 No Change ) Varies DIRECTLY with Density Ratio ( Varies DIRECTLY with Density Ratio ( Kilowatts ? Pressure V x A x PF 1000 V x A x PF x 2 1000 V x A x PF x 1.73 1000 )? Kilovolt-Am ps “kVA” ) V x A 1000 V x A x 2 1000 V x A x 1.73 1000 Horse Power HP V x A x %EFF x PF 746 V x A x %EFF x PF x 2 746 V x A x %EFF x PF x 1.73 746 ? )? ) V=VOLTS A=AMPS EFF=EFFICIENCY PF=POWER FACTOR Armstrong • BAC • Berner • Car-Mon • Cemline • ClimateMaster • Dri-Steem • Energy Labs • FabricAir Fulton • Greenheck • Lochinvar • Price • Pro Hydronic • VMC/Amber Booth • Yaskawa
PSYCHROMETRIC CHART 55 60 50 Wet-Bulb Temperature 90 200 Humidity Ratio, Dew Point Temp. Relative Humidity at 100% SPECIFIC VOLUME - CUBIC FEET PER POUND OF DRY AIR Saturation Line 190 Relative 85 45 Humidity 60 85 90 Enthalpy Vapor Pressure Humidifcation 180 or 80 Dew Point Temperature 170 40 Cooling Heating Humidity Ratio 80 160 70 80 55 Dehumidifcation ETHALPY –BTU PER POUND OF DRY AIR 150 35 HUMIDITY RATIO – GRAINS OF MOISTURE PER POUND OF DRY AIR Dry-Bulb Temperature Dry-Bulb Temperature Specifc Volume 60 140 75 Wet-Bulb Temperature 75 30 130 50 50 15.0 Relative Humidity 120 Enthalpy 25 70 70 110 40 Dew Point Temperature DEWPOINT TEMPERATURE – ºF Humidity Ratio WETBULB TEMPERATURE - °F 100 65 45 20 65 90 30 Dry-Bulb Temperature Specifc Volume 14.5 80 60 60 15 70 55 55 20 40 90 60 80 50 50 10 14.0 70 50 45 60 45 40 50 40 40 10 5 RELATIVE HUMIDITY 40 13.5 35 35 35 30 30 30 30 25 20 13.0 20 20 20 10 0 15 0 10 5 10 10 0 DRYBULB TEMPERATURE – °F 110 20 10 100 50 60 70 80 30 90 40 30 0 5 10 15 20 25 ENTHALPY – BTU PER POUND OF DRY AIR
