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class ASHRAE9012013 < ASHRAE901
# @!group PlantLoop
# Determine the performance rating method specified
# design condenser water temperature, approach, and range
#
# @param plant_loop [OpenStudio::Model::PlantLoop] the condenser water loop
# @param design_oat_wb_c [Double] the design OA wetbulb temperature (C)
# @return [Array<Double>] [leaving_cw_t_c, approach_k, range_k]
def plant_loop_prm_baseline_condenser_water_temperatures(plant_loop, design_oat_wb_c)
design_oat_wb_f = OpenStudio.convert(design_oat_wb_c, 'C', 'F').get
# G3.1.3.11 - CW supply temp shall be evaluated at 0.4% evaporative design OATwb
# per the formulat approach_F = 25.72 - (0.24 * OATwb_F)
# 55F <= OATwb <= 90F
# Design range = 10F.
range_r = 10
# Limit the OATwb
if design_oat_wb_f < 55
design_oat_wb_f = 55
OpenStudio.logFree(OpenStudio::Info, 'openstudio.standards.PlantLoop', "For #{plant_loop.name}, a design OATwb of 55F will be used for sizing the cooling towers because the actual design value is below the limit in G3.1.3.11.")
elsif design_oat_wb_f > 90
design_oat_wb_f = 90
OpenStudio.logFree(OpenStudio::Info, 'openstudio.standards.PlantLoop', "For #{plant_loop.name}, a design OATwb of 90F will be used for sizing the cooling towers because the actual design value is above the limit in G3.1.3.11.")
end
# Calculate the approach
approach_r = 25.72 - (0.24 * design_oat_wb_f)
# Calculate the leaving CW temp
leaving_cw_t_f = design_oat_wb_f + approach_r
# Convert to SI units
leaving_cw_t_c = OpenStudio.convert(leaving_cw_t_f, 'F', 'C').get
approach_k = OpenStudio.convert(approach_r, 'R', 'K').get
range_k = OpenStudio.convert(range_r, 'R', 'K').get
return [leaving_cw_t_c, approach_k, range_k]
end
end
Version data entries
49 entries across 49 versions & 1 rubygems