Trane RT-PRC007-EN Electric Heating System, Natural Gas Heating System, Air Delivery Procedure

Page 13

Selection Procedure

Heating capacity selection:

1

Winter outdoor design conditions—5 F.

2

Total return air temperature — 72 F.

3

Winter outside air minimum ventilation load and cfm — 1,200 cfm and 87.2 MBh.

4

Peak heating load 225 MBh.

Utilizing unit selection in the cooling capacity procedure.

Mixed air temperature = RADB + %O.A. (OADB - RADB) = 72

+ (0.10) (0-72) = 64.8 F.

Supply air fan motor heat temperature rise = 20,600 BTU ÷ (1.085 x 12,000) cfm = 1.6 F.

Mixed air temperature entering heat module = 64.8 + 1.6 = 66.4 F.

Total winter heating load = peak heating

+ventilation load - total fan motor heat = 225 + 87.2 - 20.6 = 291.6 MBh.

Electric Heating System

Unit operating on 480/60/3 power supply. FromTable PD-9, kw may be selected for a nominal 30-ton unit operating on 480- volt power.The high heat module — 90 KW or 307 MBh will satisfy the winter

Table PD-9 also shows an air temperature rise of 23.6 F for 12,000 cfm through the 90 kw heat module.

Unit supply temperature at design heating conditions = mixed air temperature + air temperature rise = 66.4 + 23.6 = 90 F.

Natural Gas Heating System

Assume natural gas supply — 1000 Btu/ ft3. FromTable PD-11, select the high heat module (486 MBh output) to satisfy 291.6 at unit cfm.

Table PD-11 also shows air temperature rise of 37.3 F for 12,000 cfm through heating module.

Unit supply temperature design heating conditions = mixed air temperature + air temperature rise = 66.4 + 37.3 = 103.7 F.

Air Delivery Procedure

Supply air fan bhp and rpm selection. Unit supply air fan performance shown inTable PD-12 includes pressure drops for dampers and casing losses. Static pressure drops of accessory components such as heating systems, and filters if used, must be added to external unit static pressure for total static pressure determination.

The supply air fan motor selected in the previous cooling capacity determination example was 7.27 bhp with 652 rpm.

Thus, the supply fan motor selected is 7.5 hp.

To select the drive, enterTable PD-15 for a 30-ton unit. Select the appropriate drive for the applicable rpm range. Drive selection letter C with a range of 650 rpm, is required for 652 rpm.Where altitude is significantly above sea level, useTable PD-2 and PD-3, and Figure PD-1 for applicable correction factors.

Unit Electrical Requirements

Selection procedures for electrical requirements for wire sizing amps, maximum fuse sizing and dual element fuses are given in the electrical service selection of this catalog.

Unit Designation

After determining specific unit characteristics utilizing the selection procedure and additional job information, the complete unit model number can be developed. Use the model number nomenclature on page 14.

heating load of 291.6 MBh.

Figure SP-1 — Fan Motor Heat

 

STANDARD MOTOR

 

 

 

HIGH EFFICIENCY MOTOR

 

120

 

 

 

 

 

 

 

 

 

110

 

 

 

 

 

 

 

 

MBH

100

 

 

 

 

 

 

 

 

90

 

 

 

 

 

 

 

 

-

 

 

 

 

 

 

 

 

 

HEAT

80

 

 

 

 

 

 

 

 

70

 

 

 

 

 

 

 

 

MOTOR

60

 

 

 

 

 

 

 

 

50

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

FAN

40

 

 

 

 

 

 

 

 

30

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

20

 

 

 

 

 

 

 

 

 

10

 

 

 

 

 

 

 

 

 

0

 

 

 

 

 

 

 

 

 

0

5

10

15

20

25

30

35

40

MOTOR BRAKE HORSE POWER

RT-PRC007-EN

13

Image 13
Contents Packaged Rooftop Air Conditioners American Standard Inc IntroductionContents Standard Features Features and BenefitsOptional Features Trane 3-DScroll Compressor Proven DesignThroughTesting and ResearchSimple Design with 70% Fewer Parts LowTorque VariationQuality and Reliability Features BenefitsMicro Controls MicroEase of Installation RigorousTestingSingle Point Power FC Fans with Inlet GuideVanesValue Easy to ServiceVariTrac Exhaust Air Options Application Recommendations Power Exhaust FanBarometric Relief Dampers Altitude CorrectionsClearance Requirements Acoustical ConsiderationsDuct Design Supply Air Fan Selection ProcedureElectric Heating System Air Delivery ProcedureNatural Gas Heating System Unit Electrical RequirementsModel Number Description Table GD-1 General Data 27 1/2 30 Tons General DataTable GD-2- General Data 35-40Ton Table GD-3- General Data 50Ton Table PD-1- Enthalpy of Saturated AIR Performance Adjustment FactorsTable PD-3 Gas Heating Capacity Altitude Correction Factors Table PD-4 27 1/2 Ton Gross Cooling Capacities MBh Performance DataTable PD-5- 30Ton Gross Cooling Capacities Mbh Table PD-7 40Ton Gross Cooling Capacities Mbh Table PD-6 35Ton Gross Cooling Capacities MbhTable PD-8 50Ton Gross Cooling Capacities MBh Table PD-10 Available Electric Heat KW Ranges Table PD-9 Electric Heat AirTemperature RiseTable PD-11 Natural Gas Heating Capacities Static Pressure in. wg1 Table PD-12 Supply Fan Performance 27½ 35TonTable PD-13 Supply Fan Performance 40 and 50Ton Heating System Filters2 Nominal Table PD-14 Component Static Pressure Drops in.W.G.1Gas Heat Electric Heat3 ID Coil 20 HP Table PD-15 Supply Air Fan Drive SelectionsNominal Drive Table PD-16- Power Exhaust Fan Performance VAV Units Only ControlsCV Units Only Supply AirTempering Unoccupied ZoneTemperature Control Cooling and HeatingAuto Changeover ConventionalThermostat InterfaceFan Failure Switch Occupied/Unoccupied SwitchingCoil Freeze Protection Frostat Night Setback SensorsElectrical Data Electrical Service SizingSet 2. Rooftop units with Electric Heat Table ED-2 27½-50Ton Electrical Service Sizing Data1 Figure DD-1 27 1/2 35Tons TC,TE,YC Low Heat Dimensional DataDimensional Data Figure DD-3 40-50Tons TC,TE,YC Low & High Heat Field Installed Sensors DimensionalConstant Integrated Comfort System Sensors CV and VAVTableW-2 Point Loading AverageWeight1 WeightsTableW-3 ComponentWeights TableW-4 Minimum Operating Clearances for Unit InstallationMechanical Specifications Unit Options Accessories LP Conversion Kit 20-60Ton File Number PL-RT-TC/TE/YC-27½ 50-TONS-PRC0007-EN-10-2001 Literature Order Number

RT-PRC007-EN specifications

The Trane RT-PRC007-EN is a part of Trane’s highly regarded line of air-cooled chillers, designed to provide exceptional performance and efficiency for a variety of commercial applications. This model is known for its robust engineering and cutting-edge technologies, making it a favored choice among facility managers and HVAC professionals.

One of the key features of the RT-PRC007-EN is its energy efficiency. Its advanced compressor design, alongside innovative heat exchanger technology, allows it to achieve significant energy savings, meeting or exceeding standards set by the Department of Energy. This efficiency not only results in lower operational costs but also contributes to a smaller carbon footprint, making it an environmentally friendly choice.

The chiller is equipped with variable speed compressors which adjust their output in relation to the cooling demand. This feature ensures optimal performance at all times, reducing energy consumption during partial load operations. Additionally, the RT-PRC007-EN incorporates Trane's unique Adaptive Control technology. This intelligent control system continuously monitors system parameters and environmental conditions, optimizing performance in real-time to ensure reliable operation.

Another standout characteristic of the RT-PRC007-EN is its quiet operation. The inclusion of sound-dampening technology and strategically placed acoustic insulation allows this chiller to operate with minimal noise, making it suitable for installations in noise-sensitive environments like hospitals or schools.

Durability is another hallmark of the RT-PRC007-EN. Built with high-quality materials, it is designed to withstand harsh operating conditions. Its corrosion-resistant components ensure longevity and reduce the need for extensive maintenance, making it a reliable choice for operators.

Lastly, the RT-PRC007-EN comes with a variety of customization options, including different refrigerant types, control systems, and capacity configurations. This flexibility allows it to adapt to the specific needs of different applications and building designs.

In summary, the Trane RT-PRC007-EN represents a fusion of efficiency, reliability, and advanced technology, making it an excellent option for those seeking a cutting-edge air-cooled chiller for their commercial HVAC needs.