| Power Conversion Formulas: | ||
| Multiply Watts | by 3.412 | to get BTU/hr |
| Multiply HP | by 745.7 | to get Watts |
| 1 kWhr/m2 = 86.4 Langleys (cal/cm2) | 1 BTU/ft2 = 0.0032 kWhr/m2 | 5. Heat Capacity of Air (BTUs) = 0.0182 BTU/Ft3-Degree F) |
| 1 kWhr = 3413 BTU = 860 food calories | 1 BTU = 252 cal = 0.0003 kWhr | 1 kW = 3600 kJ |
| 1 therm = 100,000 BTU = 29.3 kWh | 1 therm of natural gas = 11.6 lbs carbon released into atmosphere | 1 kWh = 3414 BTU |
| 1 watt = 3.413 BTU/hr | 1Watt = 1 Joule/Sec | 1 horsepower = 745.7 watts |
| Energy Conversion Formulas | ||
| Multiply Therms | by 100,000 | to get BTU s |
| Multiply Therms | by 29.3 | to get kWh |
| Multiply kWh | By 3,414 | to get BTU s |
| Multiply kWh | by 3,600,000 | to get Joules |
| Multiply BTU | by 1055 | to get Joules |
| Solar Insolation Conversions | ||
| Multiply kWh/m2 | by 317 | to get BTU/ft2 |
| Multiply kWh/m2 | by 3.6 | to get MJ/m2 |
| Multiply MJ/m2 | by 88.04 | to get BTU/ft2 |
| Weights and Measures | ||
| 1 Kg = 2.2 Lb | 1 Lb = 0.4536 Kg | |
| C = 5/9(F-32) | F= 9/5 C +32 | |
| 1 in. = 0.0254 meters | 1 meter = 3.281 Ft | |
| Weights and Measures (cont.) | ||
| 1 ft = 0.3048 meters | 1 meter = 3.28 Ft | 1 m3 = 264.2 gall |
| 1 ft2 = 0.929 m2 | 1m2 = 10.76 ft2 | 1ft3 = 1728 cu in |
| 1 ft3 = 0.0283 cu meters = 7.5 gall | 1m3= 35.315 cu ft = 1.308 yd3 | |
| 1 Gall H2O = 8.34 lbs | ||
| 1 Gall = 3.7854 Liters | 1 Liter = 0.2642 G | 1 Gall = 230.4 cu in |
| Energy Equivalents | ||
| 1 ton of coal = 7500 kWh | 1 gallon of oil = 132,000 BTU | |
| 1 gallon of gasoline = 37 kWh | 1 gallon of gasoline =125,000 BTUs | 1 gallon of gasoline = 500 hours human work (62 days) |
| 1 cubic foot of natural gas = 1000 BTU = 0.3 kWh | 1 barrel of crude oil = 1700 kWh | 1 ton uranium ore = 164 million kWh |
| MBH = 1000 BTU/hr | 1 therm of natural gas = 11.6 lbs carbon released into atmosphere | 100,000 BTU from Natural Gas releases 11.6 lbs carbon |
| Constants: | ||
| Montrose insolation in December/January (approximately) 180 Langleys or 2 kWhr/m2 | Montrose insolation in July = 650 Langleys or 7.6 kWhr/m2 | (source: COAGMET @ Colostate.edu) |
| C = 5/9(F-32) | F= 9/5 C +32 | |
| Montrose, CO, Latitude = 38.5 deg. | Tropic of Cancer Latitude = 23.5 deg | Montrose Dec 21st NOON sun angle = 27.5 |
| Definitions: | ||
| Langley = heat needed to raise 1gram H2O 1 deg C | Langley Units: gram-calorie/cm2 | 1 Langley = 0.2711 BTU/ft2 |
| KiloCalorie - heat required to raise i KG (1L) water from 16.5 to 17.5 degrees C. | 1 BTU raises 1 lb water by 1 degree F; approximately equiv. to energy in one wooden match. | 8.34 BTU raises 1 gall water by 1 degree F |
| Definitions (cont): | ||
| 1 BTU = 252 calories | H2O heat of fusion =80kCal/Kg or 36.4 kCal/Lb or 144.5 BTU/lb | 1 Cal = 0.00397 BTU |
| Overall Coefficient of Heat Transfer U = BTU/hr-ft2-F | U= 1/R | H2O Heat of Vaporization = 970 BTU/Lb or 539 cal/gm |
| Heat of Fusion for 1 gall water = 1205 BTU/gall | Heat Required to Raise 1 Gall from 32 – 212 Deg F = 180 BTU/Gall | Heat of Vaporization for 1 Gall H2O = 8090 BTU/Gall |
| Langley = gram-calorie/cm2 or amt heat to raise 1 g h20 by 1 degree C | 1 Langley = 0.2711 BTU/ft2 | |
| Conductivity, k = Heat transfer through 1” of material with a 1 deg F difference | Conductance, C = Heat transfer through a given thickness of material with a 1 deg F difference. | C=k/X where X = thickness of material (ft). Also, R=1/C or R=X/k, or (since U= 1/R), U=k/X |
| R Value = thickness of material (in inches) / k | Heat Loss (in BTU’s/hr) = Area (in ft2) / {R * Delta T} (in deg F) | |
| Hydronics: | ||
| head (feet) / 2.31 = psi (water) | 2.31 ft. head = 1 psi | |
| psi x 2.31 = head (feet) | head (feet) x 0.433 = psi | (note: 0.433 x 2.31 = 1) |
| Hydronics Rules of Thumb: | (note: You can also ask the plumbing supplier’s heat expert!) | |
| Heat Delivery Flow Rate (water) | F (gpm) =Boiler Rated Output 10,000 | Glycol will increase flow requirement somewhat |
| Pump Head Requirement | 1. Measure longest run in ft. 2. Add 50% to that figure | 3. Multiply by .04 4. Result is pump head rqmt. |
| Max Flow Rate/Heat Carrying Capacity for various CU pipe sizes | 1/2” - 1.5 gpm, 15K BTU 3/4” - 4 gpm, 40K BTU | 1” - 8 gpm, 80K BTU 1.25” - 14 gpm, 140K BTU |
| Copper: | Gallons per Linear Foot (type”M”) | |
| 1/2” | .0132 | |
| 3/4” | .0269 | |
| 1” | .0454 | |
| 1-1/4” | .0681 | |
| 1-1/2” | .0951 | |
| 95%Tin 5% Antimony | melting point – 452 to 464 deg F. | ASTM Alloy SB-5 |
| 50%Tin 50% Lead | melting point – 361 to 421 deg F. | ASTM Alloy SN-50 |
| (95/5 Tin/copper | melting point –440-500degF | ASTM Alloy E |
| Tin/Antimony/Silver/Copper/ Nickel | melting point –460-630degF. | ASTM Alloy HB |
| PEX: | Gallons per 100 Linear Ft | Uponor HePex |
| 3/8” nominal | 0.50 | |
| 1/2” | 0.92 | |
| 5/8” | 1.34 | |
| 3/4” | 1.84 | |
| 1” | 3.03 | |
| 1.25” | 5.00 | estimated |
| 1.5” | 7.00 | estimated |
| HePex linear exp = 1.1" per 100' per 10 deg F. | ||