Heat Controller HBH/V manual Cooling, Selection Procedure

Engineering Design Guide HBH/V SERIES Heat Controller, Inc.

Selection Procedure

Reference Calculations

Heating

LWT = EWT -		HE
	GPM x 500
LAT = EAT +		HC
		CFM x1.08

Cooling

LWT = EWT +	HR			LC = TC - SC
	GPM x 500
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

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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