Reference calculations, Legend, Abbreviations and definitions – WaterFurnace Envision Hydronic (NDW) User Manual
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NDW INSTALLATION MANUAL
HE
GPM x 500*
Legend
Abbreviations and Definitions
Reference Calculations
Heating Calculations:
Cooling Calculations:
LWT = EWT +
HR
GPM x 500*
LWT = EWT -
NOTE: * When using water. Use 485 for 15% methanol/water or Environol solution.
ELT
= entering load fluid temperature to heat pump
EER
= cooling energy effciency (TC/KW)
LLT
= leaving load fluid temperature from heat pump
PSI
= pressure drop in pounds per square inch
LGPM = load flow in gallons per minute
FT HD = pressure drop in feet of head
LWPD = load heat exchanger water pressure drop
KW =
kilowatt
EST
= entering source fluid temperature to heat pump
HR
= heat rejected in MBTUH
LST
= leaving source fluid temperature from heat pump
TC
= total cooling capacity in MBTUH
SGPM = source flow in gallons per minute
COP
= coefficient of performance (HC/KW x 3.413)
SWPD = source heat exchanger water pressure drop
HC
= heating capacity in MBTUH
HE
= heat of extraction in MBTUH