Selection Procedure

AIR DELIVERY PROCEDURE

Supply fan performance tables include internal resistance of rooftop. For total static pressure determination, system external static must be added to appropriate component static pressure drop (evaporator coil, filters, optional economizer, optional exhaust fan, optional heating system, optional cooling only extended casing, optional roof curb).

Supply Fan Motor Sizing

The supply fan motor selected in the cooling capacity determination was 15.3 bhp and 924 rpm.Thus, a 20 hp supply fan motor is selected. EnterTable PD-45 to select the proper drive. For a 50 ton rooftop with 20 hp motor, a drive number 9 — 900 rpm is selected.

Exhaust Fan Motor Sizing

The exhaust fan is selected based on total return system negative static pressure and exhaust fan cfm. Return system negative static include return duct static and roof curb static pressure drop.

Return duct static pressure = 0.65 inches

Trane roof curb (Table PD-43) = 0.12 inches

Total return system negative static pressure = 0.77 inches

Exhaust fan cfm = 12,000 cfm

FromTable PD-47, the required bhp is

3.45hp at 574 rpm.Thus, the exhaust fan motor selected is 5 hp.

To select a drive, enterTable PD-49 for a 5 hp motor for a 50 ton unit. Drive selection number 6 — 600 rpm.

Where altitudes are significantly above sea level, useTables PAF-2 and PAF-3 and Figure PAF-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 section of this catalog.

Altitude Corrections

The rooftop performance tables and curves of this catalog are based on standard air (.075 lbs/ft). If the rooftop airflow requirements are at other than standard conditions (sea level), an air density correction is needed to project accurate unit performance.

Figure PAF-1 shows the air density ratio at various temperatures and elevations. Trane rooftops are designed to operate between 40 and 90 degrees Fahrenheit leaving air temperature.

The procedure to use when selecting a supply or exhaust fan on a rooftop for elevations and temperatures other than standard is as follows:

1

First, determine the air density ratio using Figure PAF-1.

2

Divide the static pressure at the nonstandard condition by the air density ratio to obtain the corrected static pressure.

3

Use the actual cfm and the corrected static pressure to determine the fan rpm and bhp from the rooftop performance tables or curves.

4

The fan rpm is correct as selected.

5

Bhp must be multiplied by the air density ratio to obtain the actual operating bhp.

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RT-PRC010-EN

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Trane RT-PRC010-EN manual Supply Fan Motor Sizing, Exhaust Fan Motor Sizing, Altitude Corrections

RT-PRC010-EN specifications

The Trane RT-PRC010-EN is a prominent model in the line of Trane's packaged rooftop units, designed to offer efficient heating, cooling, and ventilation for commercial applications. Renowned for its robust performance, this unit integrates advanced technologies and superior engineering to meet diverse environmental needs while ensuring energy efficiency and reliability.

One of the key features of the RT-PRC010-EN is its energy-efficient operation. The unit is equipped with variable-speed fans and scroll compressors, which allow for precise control over temperature and airflow. This adaptability not only enhances comfort but also contributes to significant energy savings. The inclusion of high-efficiency cooling coils further optimizes performance, making it an excellent choice for businesses looking to lower their operational costs.

The RT-PRC010-EN model integrates smart controls that allow for seamless integration into building management systems. These controls facilitate real-time monitoring and diagnostics, enabling facility managers to maintain optimum operational efficiency and promptly address any maintenance needs. This technology minimizes downtime and extends the lifecycle of the unit.

Moreover, the unit’s construction is targeted toward resilience and durability. Built with a corrosion-resistant cabinet and extensive insulation, the RT-PRC010-EN can withstand the rigors of various climates, making it suitable for installation across different geographical locations. Its compact design allows for easy installation on rooftops, maximizing space utilization in commercial buildings.

Another standout characteristic is the unit's versatility in application. The RT-PRC010-EN can be tailored to suit a wide range of commercial settings, including retail establishments, educational institutions, and healthcare facilities. Options for various indoor and outdoor configurations enhance its adaptability to specific operational requirements.

In conclusion, the Trane RT-PRC010-EN stands out as an energy-efficient, reliable, and versatile solution for commercial heating and cooling needs. Its advanced features, smart controls, and robust design make it an ideal choice for businesses looking to enhance comfort while minimizing energy expenditures and ensuring operational reliability. Whether dealing with extreme weather conditions or managing indoor air quality concerns, this rooftop unit provides a comprehensive solution tailored to modern commercial requirements.