Engineering Design Guide | HBH/V SERIES | Heat Controller, Inc. |
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Selection Procedure
Reference Calculations
Heating
LWT = EWT - |
| HE | |
GPM x 500 |
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LAT = EAT + |
| HC | |
| CFM x1.08 | ||
Cooling
LWT = EWT + | HR |
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| LC = TC - SC | |
GPM x 500 |
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LAT (DB) = EAT (DB) - |
| SC | S/T = | SC | |
CFM x1.08 | TC | ||||
Legend and Glossary of Abbreviations
BTUH = BTU( British Thermal Unit) per hour | HWC | = hot water generator (desuperheater) capacity, Mbtuh |
CFM = airflow, cubic feet/minute | IPT | = internal pipe thread |
COP = coefficient of performance = BTUH output/BTUH input | KW | = total power unit input, kilowatts |
DB = dry bulb temperature (°F) | LAT | = leaving air temperature, °F |
EAT = entering air temperature, Fahrenheit (dry bulb/wet bulb) | LC | = latent cooling capacity, BTUH |
EER = energy efficiency ratio = BTUH output/Watt input | LWT | = leaving water temperature, °F |
EPT = external pipe thread | MBTUH = 1000 BTU per hour | |
ESP = external static pressure (inches w.g.) | S/T | = sensible to total cooling ratio |
EWT = entering water temperature | SC | = sensible cooling capacity, BTUH |
GPM = water flow in U.S. gallons/minute | TC | = total cooling capacity, BTUH |
HE = total heat of extraction, BTUH | WB | = wet bulb temperature (°F) |
HC = air heating capacity, BTUH | WPD | = waterside pressure drop (psi & ft. of hd.) |
HR = total heat of rejection, BTUH |
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Conversion Table - to convert inch-pound (English) to SI (Metric)
Air Flow | Water Flow | Ext Static Pressure | Water Pressure Drop |
Airflow (L/s) = CFM x 0.472 | Water Flow (L/s) = gpm x 0.0631 | ESP (Pa) = ESP (in of wg) x 249 | PD (kPa) = PD (ft of hd) x 2.99 |
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