Selection Procedure - Heat Controller HBH Series Engineering Design Manual

Engineering Design Guide
Reference Calculations
Heating
HE
LWT = EWT -
GPM x 500
HC
LAT = EAT +
CFM x1.08
Legend and Glossary of Abbreviations
BTUH = BTU (British Thermal Unit) per hour
CFM = airfl ow, cubic feet/minute
COP = coeffi cient of performance = BTUH output/BTUH input
DB = dry bulb temperature (°F)
EAT = entering air temperature, Fahrenheit (dry bulb/wet bulb)
EER = energy effi ciency ratio = BTUH output/Watt input
MPT = male pipe thread
ESP = external static pressure (inches w.g.)
EWT = entering water temperature
GPM = water fl ow in U.S. gallons/minute
HE = total heat of extraction, BTUH
HC = air heating capacity, BTUH
HR = total heat of rejection, BTUH
Conversion Table - to convert inch-pound (English) to S-I (Metric)
Air Flow
Airflow (L/s) = CFM x 0.472 Water Flow (L/s) = gpm x 0.0631
Cooling
HR
LWT = EWT +
GPM x 500
SC
LAT (DB) = EAT (DB) -
CFM x1.08
Water Flow
ESP (Pa) = ESP (in of wg) x 249
HBH SERIES
LC = TC - SC
SC
S/T =
TC
HWC = hot water generator (desuperheater) capacity, Mbtuh
FPT = female pipe thread
KW = total power unit input, kilowatts
LAT = leaving air temperature, °F
LC = latent cooling capacity, BTUH
LWT = leaving water temperature, °F
MBTUH = 1000 BTU per hour
S/T = sensible to total cooling ratio
SC = sensible cooling capacity, BTUH
TC = total cooling capacity, BTUH
WB = wet bulb temperature (°F)
WPD = waterside pressure drop (psi & ft. of hd.)
Ext Static Pressure
3
Heat Controller, Inc.

Selection Procedure

Water Pressure Drop
PD (kPa) = PD (ft of hd) x 2.99