Operating Limits, Reference Calculations, Legend And Notes - York YACT038-072 Installation Manual

Operating Limits
Operating Limits
Air Limits
Minimum Ambient Air
Rated Ambient Air
Max. Ambient Air
Minimum Entering Air
Rated Entering Air db/wb
Maximum Entering Air db/wb
Water Limits
Minimum Entering Water
Normal Entering Water
Maximum Entering Water
Reference Calculations
Heating Calculations:
HE
LWT = EWT -
gpm x 500
HC
LAT = EAT +
cfm x 1.08
TH = HC + HW
Legend and Notes
Abbreviations and Definitions
cfm = airflow, cubic feet/minute
COP = Coefficient of Performance
= Btu output/Btu input
= [HC/(kw x 3.413)]
EAT = entering air temperature, °F
EER = Energy Efficient Ratio
= Btu output/Watt input
ELT = entering load fluid temperature to heat pump
EST = entering source fluid temperature to heat pump
EWT = entering water temperature (source) to heat pump
FT HD = pressure drop in feet of head
GPM = Gallons per minute
WPD = water pressure drop, psi and feet of water
HC = air heating capacity, MBtu/h
HE = total heat of extraction, MBtu/h
HR = total heat of rejection, MBtu/h
Notes to Performance Data Tables
The following notes apply to all performance data tables:
• Performance ratings are based on 80°F DB/67°F WB EAT for cooling and 70°F DB EAT for heating.
• Three flow rates are shown for each unit. The lowest flow rate shown is used for geothermal open loop/well water systems
with a minimum of 50°F EWT. The middle flow rate shown is the minimum geothermal closed loop flow rate. The highest
flow rate shown is optimum for geothermal closed loop systems and the suggested flow rate for boiler/tower applications.
• The hot water generator numbers are based on a flow rate of 0.4 gpm/ton of rated capacity with an EWT of 90°F.
• Entering water temperatures below 40°F assumes 15% antifreeze solution.
• For non-standard EAT conditions, apply the appropriate Correction Factor tables.
• Interpolation between EWT, gpm, and cfm data is permissible, extrapolation is not.
• Pumping power is not included in the Performance Data tables nor are calculations for AHRI/ISO 13256-1.
Cooling
°F °C
45 7.2
80 26.7
100 37.8
50 10.0
80.6/66.2 27/19
110/83 43/28.3
30 -1.1
50-110 10-43.3
120 48.9
Cooling Calculations:
HR
LWT = EWT +
gpm x 500
SC
LAT (DB) = EAT (DB) -
cfm x 1.08
LC = TC - SC
SC
S/T =
TC
AFFINITY COMBINATION INSTALLATION MANUAL
NOTES: Minimum/maximum limits are only for
Heating
start-up conditions, and are meant for bringing the
°F °C
space up to occupancy temperature. Units are not
designed to operate at the minimum/maximum
45 7.2
conditions on a regular basis. The operating limits
70 21.1
are dependant upon three primary factors: 1) water
temperature, 2) return air temperature, and 3)
85 29.4
ambient temperature. When any of the factors are
40 4.4
at the minimum or maximum levels, the other two
68 20.0
factors must be at the normal level for proper and
80 26.7
reliable unit operation.
20 -6.7
30-70 -1.1
90 32.2
kW = total power unit input, kilowatts
LAT = leaving air temperature, °F
LC = latent cooling capacity, MBtu/h
LGPM = load flow in gallons per minute
LLT = leaving load fluid temperature from heat pump
LST = leaving source fluid temperature from heat pump
LWPD = load coax water pressure drop
LWT = leaving water temperature, °F
PSI = pressure drop in pounds per square inch
S/T = sensible to total cooling ratio
SC = sensible cooling capacity, MBtu/h
SWPD= source coax water pressure drop
TC = total cooling capacity, MBtu/h
TH = total heating capacity, MBtu/h
WPD = water pressure drop in PSI, feet of water
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