Ultra Low Noise

Ultra Low Noise Air Cooled Chiller with Screw Compressor

Due to increasing awareness of noise as an environmental pollutant, Petra Engineering Industries Co. developed the Ultra-Low Noise chillers with the lowest dBA level on the market today geared towards noise-sensitive design requirements.

Petra designed the Ultra-Low Noise chillers using their “Patented Design” for the compressor compartment. In addition, the chillers use the highly efficient, low noise screw compressor and cast aluminum sickle-shaped fans with high efficiency external rotor motor, to further reduce noise levels.

When measured against the AHRI standard, the highest dBA of Petra’s chillers is lower than the minimum dBA requirement for the same tonnage listed in the ASHRAE standard. In addition, these chillers can be supplied in systems up to 1760 kW (500 Tons) and take into consideration the chiller COP in both part load and full load values.

Petra Ultra Low Noise chillers have been installed in projects that have strict sound regulations such as schools, universities, libraries and large commercial projects in residential areas of the USA, UK and other countries, where noise control is imperative. The chillers were installed near the building with minimal noise disruption to its occupants and its surrounding neighbors.

• Wide Range of Capacities: 158 kW (45 Tons) to 1547 kW (440 Tons) @ 50 Hz, 183 kW (52 Tons) to 1776 kW (505 Tons) @ 60 Hz
• Extremely low noise levels
• Ideal for Low Noise Applications
• Easy Installation and Maintenance

• Welded structural C-channel base painted with mono component catalyzed primer sprayed paint.
• Base is equipped with welded brackets for heavy duty lifting lugs.
• Structural members are made from gauge 15 [1.8 mm (0.07 inch)] tubular cross members that are semi welded with stainless steel fasteners. All members & panels (side & roof) are painted with oven baked polyester electrostatic powder paint.
• Suction gas-cooled semi-hermetic twin screw compressor with variable slide valves allow the chillers to match actual load conditions, delivering exceptional part load performance.
• Independent Refrigeration Circuits for each compressor.
• Microprocessor controller for full management of chiller operation and safety circuits.
• High efficiency direct expansion (DX) shell and tube type coolers with inner grooved tubes to optimize the cooler’s efficiency.
• Coolers are tested and stamped for refrigerant side design pressure of 1,000 kPa (145 Psi) and for a maximum water side working pressure of 1,500 kPa (220 Psi).
• Condenser coils are microchannel type (MCHE) or copper tubes copper aluminum type.
• All coils are air pressure tested by dry air up to 2,900 kPa (420 Psi) under water. They also undergo dry cleaning after manufacturing for optimum system cleanness.
• Nema 3X with IP54 minimum enclosure standard electrical panel. Two separate panels, one for power & the other for control.
• Condenser fans of the external rotor type with many attractive features such as space saving, compact design, optimum cooling, full speed controllability and low starting currents.
• Epoxy paint for all exposed copper piping system of the refrigeration circuit.
• Equipped with complete line of accessories for safe operation and control.
• Unit is fully charged unit with R-134a refrigerant.

• Copper tubes copper fins coil.
• Coil corrosion protection including polyurethane pre-coating (for aluminum fins) and polyurethane post-coating (for aluminum & copper fins).
• Pressure gauges for monitoring of refrigeration discharge and suction pressure.
• Water flow switch installed to prevent operation of unit without evaporator water flow.
• Cooler cladding of aluminum, stainless steel or painted galvanized steel {made from gauge 22 [0.7 mm (0.03 inch)}.
• Cooler can be insulated with closed cell foam insulation of 25 mm (1 inch), 38 mm (1.5 inch) & 50 mm (2 inch) The insulation density is 48 kg/m3 (3 lb/ft3) with a K-factor of 0.035 W/(m.°K) [0.0203 BTUH/(ft.°F).
• Main disconnect switch used to de-energize the power supply to the chiller during servicing or repairing works because of the door interlock with an external handle that is installed on the electric panel door.
• Power factor correction used to improve the power factor level which improves system reliability, minimizes voltage drops and gives better power quality.
• Earth leakage relay used in electrical installations with high earth impedance to prevent shock.
• Control transformer to supply power input to auxiliary components at 120 or 220 volts, such as (not limited to) bulk head light and GFI outlet.
• Ampere-meter & volt-meter used to measure the power current & voltage consumption Ampere-meter is used for each phase.
• 120 volt power supply connected through the transformer to provide a 120 volt single phase circuit that is used to operate the electric appliances at site such as laptops, tablets and cell phones.
• Speed regulator for condenser fan motors used to permit the unit to operate in low ambient temperature.
• Dual power connection, one power entry for compressors & the second for the rest of the unit.
• External over load for each compressor.
• External over load for each condenser fan motor.
• Circuit breaker for each compressor.
• Circuit breaker for each condenser fan motor.
• Nema 4x electrical panels made from galvanized steel.
• Nema 4x electrical panels made from stainless steel.
• Cooler tape heater protection down to 0°C (32°F), -18°C (0°F) & -29°C (-20°F).