class NECB2011 def model_add_swh(model, building_type, climate_zone, prototype_input, epw_file) OpenStudio.logFree(OpenStudio::Info, 'openstudio.model.Model', 'Started Adding Service Water Heating') # Add the main service water heating loop, if specified unless prototype_input['main_water_heater_volume'].nil? swh_fueltype = self.get_canadian_system_defaults_by_weatherfile_name(model)['swh_fueltype'] # Add the main service water loop unless building_type == 'RetailStripmall' && ( template != 'NECB2011' && template != 'NECB2015') main_swh_loop = model_add_swh_loop(model, 'Main Service Water Loop', nil, OpenStudio.convert(prototype_input['main_service_water_temperature'], 'F', 'C').get, prototype_input['main_service_water_pump_head'], prototype_input['main_service_water_pump_motor_efficiency'], OpenStudio.convert(prototype_input['main_water_heater_capacity'], 'Btu/hr', 'W').get, OpenStudio.convert(prototype_input['main_water_heater_volume'], 'gal', 'm^3').get, swh_fueltype, OpenStudio.convert(prototype_input['main_service_water_parasitic_fuel_consumption_rate'], 'Btu/hr', 'W').get) end # Attach the end uses if specified in prototype inputs # TODO remove special logic for large office SWH end uses # TODO remove special logic for stripmall SWH end uses and service water loops # TODO remove special logic for large hotel SWH end uses if prototype_input['main_service_water_peak_flowrate'] # Attaches the end uses if specified as a lump value in the prototype_input model_add_swh_end_uses(model, 'Main', main_swh_loop, OpenStudio.convert(prototype_input['main_service_water_peak_flowrate'], 'gal/min', 'm^3/s').get, prototype_input['main_service_water_flowrate_schedule'], OpenStudio.convert(prototype_input['main_water_use_temperature'], 'F', 'C').get, nil) else # Attaches the end uses if specified by space type space_type_map = @space_type_map building_type = 'Space Function' puts space_type_map space_type_map.sort.each do |space_type_name, space_names| search_criteria = { 'template' => template, 'building_type' => model_get_lookup_name(building_type), 'space_type' => space_type_name } data = model_find_object(standards_data['space_types'], search_criteria) # Skip space types with no data next if data.nil? # Skip space types with no water use, unless it is a NECB archetype (these do not have peak flow rates defined) # Add a service water use for each space space_names.sort.each do |space_name| space = model.getSpaceByName(space_name).get space_multiplier = nil # Added this to prevent double counting of zone multipliers.. space multipliers are never used in NECB archtypes. space_multiplier = 1 model_add_swh_end_uses_by_space(model, main_swh_loop, space, space_multiplier) end end end end # Add the booster water heater, if specified unless prototype_input['booster_water_heater_volume'].nil? # Add the booster water loop swh_booster_loop = model_add_swh_booster(model, main_swh_loop, OpenStudio.convert(prototype_input['booster_water_heater_capacity'], 'Btu/hr', 'W').get, OpenStudio.convert(prototype_input['booster_water_heater_volume'], 'gal', 'm^3').get, prototype_input['booster_water_heater_fuel'], OpenStudio.convert(prototype_input['booster_water_temperature'], 'F', 'C').get, 0, nil) # Attach the end uses model_add_booster_swh_end_uses(model, swh_booster_loop, OpenStudio.convert(prototype_input['booster_service_water_peak_flowrate'], 'gal/min', 'm^3/s').get, prototype_input['booster_service_water_flowrate_schedule'], OpenStudio.convert(prototype_input['booster_water_use_temperature'], 'F', 'C').get) end # Add the laundry water heater, if specified unless prototype_input['laundry_water_heater_volume'].nil? # Add the laundry service water heating loop laundry_swh_loop = model_add_swh_loop(model, 'Laundry Service Water Loop', nil, OpenStudio.convert(prototype_input['laundry_service_water_temperature'], 'F', 'C').get, prototype_input['laundry_service_water_pump_head'], prototype_input['laundry_service_water_pump_motor_efficiency'], OpenStudio.convert(prototype_input['laundry_water_heater_capacity'], 'Btu/hr', 'W').get, OpenStudio.convert(prototype_input['laundry_water_heater_volume'], 'gal', 'm^3').get, prototype_input['laundry_water_heater_fuel'], OpenStudio.convert(prototype_input['laundry_service_water_parasitic_fuel_consumption_rate'], 'Btu/hr', 'W').get) # Attach the end uses if specified in prototype inputs model_add_swh_end_uses(model, 'Laundry', laundry_swh_loop, OpenStudio.convert(prototype_input['laundry_service_water_peak_flowrate'], 'gal/min', 'm^3/s').get, prototype_input['laundry_service_water_flowrate_schedule'], OpenStudio.convert(prototype_input['laundry_water_use_temperature'], 'F', 'C').get, nil) end OpenStudio.logFree(OpenStudio::Info, 'openstudio.model.Model', 'Finished adding Service Water Heating') return true end # add swh # Applies the standard efficiency ratings and typical losses and paraisitic loads to this object. # Efficiency and skin loss coefficient (UA) # Per PNNL http://www.energycodes.gov/sites/default/files/documents/PrototypeModelEnhancements_2014_0.pdf # Appendix A: Service Water Heating # # @return [Bool] true if successful, false if not def water_heater_mixed_apply_efficiency(water_heater_mixed) # Get the capacity of the water heater # TODO add capability to pull autosized water heater capacity # if the Sizing:WaterHeater object is ever implemented in OpenStudio. capacity_w = water_heater_mixed.heaterMaximumCapacity if capacity_w.empty? OpenStudio.logFree(OpenStudio::Warn, 'openstudio.standards.WaterHeaterMixed', "For #{water_heater_mixed.name}, cannot find capacity, standard will not be applied.") return false else capacity_w = capacity_w.get end capacity_btu_per_hr = OpenStudio.convert(capacity_w, 'W', 'Btu/hr').get capacity_kbtu_per_hr = OpenStudio.convert(capacity_w, 'W', 'kBtu/hr').get # Get the volume of the water heater # TODO add capability to pull autosized water heater volume # if the Sizing:WaterHeater object is ever implemented in OpenStudio. volume_m3 = water_heater_mixed.tankVolume if volume_m3.empty? OpenStudio.logFree(OpenStudio::Warn, 'openstudio.standards.WaterHeaterMixed', "For #{water_heater_mixed.name}, cannot find volume, standard will not be applied.") return false else volume_m3 = volume_m3.get end volume_gal = OpenStudio.convert(volume_m3, 'm^3', 'gal').get # Get the heater fuel type fuel_type = water_heater_mixed.heaterFuelType unless fuel_type == 'NaturalGas' || fuel_type == 'Electricity' OpenStudio.logFree(OpenStudio::Warn, 'openstudio.standards.WaterHeaterMixed', "For #{water_heater_mixed.name}, fuel type of #{fuel_type} is not yet supported, standard will not be applied.") end # Calculate the water heater efficiency and # skin loss coefficient (UA) # Calculate the energy factor (EF) # From PNNL http://www.energycodes.gov/sites/default/files/documents/PrototypeModelEnhancements_2014_0.pdf # Appendix A: Service Water Heating water_heater_eff = nil ua_btu_per_hr_per_f = nil sl_btu_per_hr = nil case fuel_type when 'Electricity' volume_l_per_s = volume_m3 * 1000 if capacity_btu_per_hr <= OpenStudio.convert(12, 'kW', 'Btu/hr').get # Fixed water heater efficiency per PNNL water_heater_eff = 1 # Calculate the max allowable standby loss (SL) sl_w = if volume_l_per_s < 270 40 + 0.2 * volume_l_per_s # assume bottom inlet else 0.472 * volume_l_per_s - 33.5 end # assume bottom inlet sl_btu_per_hr = OpenStudio.convert(sl_w, 'W', 'Btu/hr').get else # Fixed water heater efficiency per PNNL water_heater_eff = 1 # Calculate the max allowable standby loss (SL) # use this - NECB does not give SL calculation for cap > 12 kW sl_btu_per_hr = 20 + (35 * Math.sqrt(volume_gal)) end # Calculate the skin loss coefficient (UA) ua_btu_per_hr_per_f = sl_btu_per_hr / 70 when 'NaturalGas' if capacity_btu_per_hr <= 75_000 # Fixed water heater thermal efficiency per PNNL water_heater_eff = 0.82 # Calculate the minimum Energy Factor (EF) base_ef = 0.67 vol_drt = 0.0019 ef = base_ef - (vol_drt * volume_gal) # Calculate the Recovery Efficiency (RE) # based on a fixed capacity of 75,000 Btu/hr # and a fixed volume of 40 gallons by solving # this system of equations: # ua = (1/.95-1/re)/(67.5*(24/41094-1/(re*cap))) # 0.82 = (ua*67.5+cap*re)/cap cap = 75_000.0 re = (Math.sqrt(6724 * ef**2 * cap**2 + 40_409_100 * ef**2 * cap - 28_080_900 * ef * cap + 29_318_000_625 * ef**2 - 58_636_001_250 * ef + 29_318_000_625) + 82 * ef * cap + 171_225 * ef - 171_225) / (200 * ef * cap) # Calculate the skin loss coefficient (UA) # based on the actual capacity. ua_btu_per_hr_per_f = (water_heater_eff - re) * capacity_btu_per_hr / 67.5 else # Thermal efficiency requirement from 90.1 et = 0.8 # Calculate the max allowable standby loss (SL) cap_adj = 800 vol_drt = 110 sl_btu_per_hr = (capacity_btu_per_hr / cap_adj + vol_drt * Math.sqrt(volume_gal)) # Calculate the skin loss coefficient (UA) ua_btu_per_hr_per_f = (sl_btu_per_hr * et) / 70 # Calculate water heater efficiency water_heater_eff = (ua_btu_per_hr_per_f * 70 + capacity_btu_per_hr * et) / capacity_btu_per_hr end end # Convert to SI ua_btu_per_hr_per_c = OpenStudio.convert(ua_btu_per_hr_per_f, 'Btu/hr*R', 'W/K').get # Set the water heater properties # Efficiency water_heater_mixed.setHeaterThermalEfficiency(water_heater_eff) # Skin loss water_heater_mixed.setOffCycleLossCoefficienttoAmbientTemperature(ua_btu_per_hr_per_c) water_heater_mixed.setOnCycleLossCoefficienttoAmbientTemperature(ua_btu_per_hr_per_c) # TODO: Parasitic loss (pilot light) # PNNL document says pilot lights were removed, but IDFs # still have the on/off cycle parasitic fuel consumptions filled in water_heater_mixed.setOnCycleParasiticFuelType(fuel_type) # self.setOffCycleParasiticFuelConsumptionRate(??) water_heater_mixed.setOnCycleParasiticHeatFractiontoTank(0) water_heater_mixed.setOffCycleParasiticFuelType(fuel_type) # self.setOffCycleParasiticFuelConsumptionRate(??) water_heater_mixed.setOffCycleParasiticHeatFractiontoTank(0.8) # set part-load performance curve if fuel_type == 'NaturalGas' plf_vs_plr_curve = model_add_curve(water_heater_mixed.model, 'SWH-EFFFPLR-NECB2011') water_heater_mixed.setPartLoadFactorCurve(plf_vs_plr_curve) end # Append the name with standards information water_heater_mixed.setName("#{water_heater_mixed.name} #{water_heater_eff.round(3)} Therm Eff") OpenStudio.logFree(OpenStudio::Info, 'openstudio.model.WaterHeaterMixed', "For #{template}: #{water_heater_mixed.name}; thermal efficiency = #{water_heater_eff.round(3)}, skin-loss UA = #{ua_btu_per_hr_per_f.round}Btu/hr") return true end end