AAON RZ Series Packaged Rooftop Units

Standard Features

• Air-cooled unit capacity ranging from 45 to 240 tons or evaporative condenser unit capacity ranging from 51 to 261 tons.
• Available as a chilled water, or non-compressorized DX air handling unit from 7,500-75,000 cfm.
• AHRI certified performance for proven efficiency.
• Walk-in service vestibule provides shelter for maintenance and service personnel.
• Walk-in hinged access doors with full length stainless steel piano hinges and quarter-turn, lockable handles.
• Aluminum tread plate floor covering within the vestibule for improved durability and safety.
• Compressor isolation valves are standard for improved service efficiency.
• Draw-through or blow-through configurations available with direct drive backwards curved plenum fans allow design flexibility.
• AMCA certified and labeled low leakage economizer dampers utilize outdoor air for cooling under certain conditions.
• Corrosion resistant polyurethane paint exceeds a 2,500-hour salt spray test.
• Standard five-year non-prorated compressor warranty.
• 15-year non-prorated, aluminized steel gas heat exchanger warranty, and 25-year non-prorated stainless steel gas heat exchanger warranty.

Key Components

Evaporator Coils

Variable speed circuits are equipped with an electronic expansion valve, while tandem circuits feature a thermal expansion valve. Consistent air temperatures are achieved with variable speed circuits covering the entire surface of the evaporator coil. A double-sloped stainless steel drain pan ensures positive drainage. Units with upper and lower coils are equipped with intermediate drain pans. Tubing is dressed and structurally supported for lasting reliability.

Microchannel Air-Cooled Condenser Coils

Microchannel condenser coils are more efficient, lighter, and use less refrigerant than traditional fin and tube condenser coils.

Compressors

Each interlaced evaporator coil includes one circuit with a VFD (Variable Frequency Drive) variable speed compressor, ensuring consistent air temperature across the coil face at all operating conditions. During part-load operation, the system optimizes costs by reducing compressor capacity. Variable speed compressors utilize inverter-driven permanent magnet motors for unit turndown down to 11% on certain models. The RZ Series delivers exceptional efficiency, with IEER ratings for part loads reaching as high as 20.8.

Construction and Serviceability

Durable, Energy-Efficient Design

Double-wall construction uses closed-cell polyurethane foam insulation with G90 galvanized steel walls, offering superior durability and less unwanted heat transfer compared to fiberglass insulation. With an insulation R-Value of 16, it creates a more rigid assembly.

Streamlined Serviceability

AAON equipment prioritizes efficient serviceability, reducing downtime and costs. Easily accessible compressors, control components, color-coded wiring diagrams, and labeled components minimize delays in evaluating service issues, ensuring low service costs and maximizing unit run time.

Accessible Cabinet Doors

Access doors feature full-length stainless steel piano hinges and quarter-turn, lockable handles, providing improved reliability over single-point hinges and making the unit easily serviceable.

Quiet Fan Array Technology

State-of-the-art computer simulations and laboratory testing were utilized to design motor mount frames with minimal vibration and sound. Each fan module is built on a dedicated assembly line with auto laser cutting and robot welding for consistent, high-quality production. Fan modules are powder coated for corrosion protection.

Increased Thermal Resistance

Double-wall, rigid polyurethane foam-injected cabinet panels increase thermal resistance, reduce air leakage, and attenuate radiated sound. A thermal break reduces heat transfer between interior and exterior metal cabinet walls.

Configurability

Air-Cooled Condensing

Microchannel condenser coils offer enhanced heat transfer, are up to 60% lighter, and use less refrigerant than traditional coils. All condenser coils are designed for at least 10°F of refrigerant sub-cooling. VFDs are factory-installed on condenser fans for head pressure control, a greater operating temperature range, and reduced sound levels at off-design ambient temperatures. Condenser fans are direct-drive, axial-flow propeller type, discharging vertically.

Eco-Friendly Evaporative Condenser

The RZ Series evaporative condenser units deliver outstanding energy efficiency and operational cost savings compared to air-cooled designs, ideal for locations requiring a central chiller and cooling tower. Energy costs can be reduced by 20% to 40% annually depending on application and location. Equipped with an air-cooled desuperheater and low-sound ECM (Electronically Commutated Motor) driven variable-speed condenser fans, AAON's evaporative condenser uses 22-100% less water and 22-100% less chemical usage than conventional evaporative condensers. The interior is constructed with 304 stainless steel and other non-corrosive materials. Desuperheater coils feature polymer e-coating for corrosion protection.

Configurable Air Handling Unit

The RZ Series is well-suited for applications without compressors. When configured as an air handling unit, it is built without a condensing section, walk-in compressor, and control vestibule but retains all other features. Options include DX coils and expansion valves, and chilled water coils in 4, 6, or 8 rows. Air handling units may be specified with any heating options for a year-round rooftop heating and cooling package.

High-Efficiency Supply Fan Arrays

The RZ Series offers supply fan arrays with up to 12 fans using high-efficiency direct-drive airfoil plenum fans with permanent magnet motors. This design uses multiple smaller diameter fans for quieter operation compared to a single larger diameter fan. All fans are directly driven by the motor, eliminating drive belt assemblies and associated maintenance. Backdraft dampers are available for operational redundancy.

Options

• Gas heat up to 4500 MBH available with staged or high turndown modulating gas heat for greater fuel efficiency and improved comfort. Direct-fired gas heat is also available.
• Hot water and steam coils offered in 1 or 2-row configurations with multiple face areas; hot water also available in 4-row configurations.
• SCR (Silicon Controlled Rectifier) electric heat control for reduced power consumption, longer heater life, and improved occupant comfort.
• Humidity control options: High Capacity Coils, Return Air Bypass, and Modulating Hot Gas Reheat.
• Multiple high-efficiency air filtration options, including HEPA, for improved indoor air quality by reducing airborne allergens and pollutants. Final filters available with up to MERV 14 media in gas heat units. HEPA final filtration is available.
• Factory-installed AAONAIRE™ total and sensible energy recovery wheels for pre-conditioning air, reducing heating and cooling loads.
• Power exhaust and power return fans with economizer for application flexibility.
• LED Marine service lights for quick and convenient maintenance.
• Double-pane viewing windows can be installed in all doors for viewing operating equipment or interior cabinets.
• 115V convenience outlet option available.
• Sound attenuators for a quieter and more comfortable environment.
• Air mixer for blending return and outdoor air to prevent frozen coils and ensure consistent operation at specific outdoor-air design temperatures.
• Phase and Brownout protection against voltage imbalance.
• Polymer e-coated coils for corrosion protection.
• Interior corrosion protection option for components in corrosive environments.
• Option boxes available for field-installed components without the trouble of installation and service in a crowded cabinet.
• Different paint color options available for unit customization.
• Additional customization available by request.
• Low-sound air-cooled condenser fans engineered for peak performance and quiet operation.

Low GWP Refrigerant

AIM ACT Compliant

The AIM Act of 2020 empowered the U.S. Environmental Protection Agency to manage Hydrofluorocarbons (HFCs) and regulate refrigerants based on global warming potential (GWP). The final ruling mandating all new air conditioners to use refrigerants with a GWP below 700 is anticipated to begin January 1, 2025. AAON has thoroughly researched and tested low GWP refrigerants and selected R-454B for its similarity to R-410A in capacity and properties, requiring less product redesign. With a GWP of 466, R-454B is well below the upcoming regulation limits. AAON selected R-454B, a sub-500 GWP refrigerant, to drive the industry towards a cleaner and more sustainable future.

Indoor Air Quality

The quality of air inside a building impacts health and cognition. AAON standard design and rooftop equipment options improve indoor air quality.

Economizer

Factory-installed, sensible or enthalpy-controlled AMCA certified Class 2 low leakage gear-driven dampers allow for free cooling and indoor air quality control.

Fan Selection

The RZ Series offers versatile configurations as either draw-through or blow-through arrangements with supply or return fans. Supply blower assemblies feature direct-drive, unhoused, single-inlet fans, offered in two different widths for versatile application. The most efficient alternatives are determined for the application as a function of fan quantity, fan diameter, fan blade width, and RPM. Inlet and outlet sound ratings are provided for each fan combination and determined for the overall unit configuration. Multiple fans provide improved reliability, greater efficiency, lower sound levels, and greater service options.

AAONAIRE™ Energy Recovery Wheel

Sensible-only or enthalpy energy recovery wheels can be used to pre-condition outside air, greatly improving energy savings and reducing unit operating costs, especially on makeup air units. Energy recovery wheels are offered as polymer or aluminum construction with removable segments for quick cleaning.

Outside Air Ventilation

Bringing fresh outside air into a building helps flush out infectious aerosols and reduces CO2 levels in the space. High-capacity cooling coils are available to handle the higher latent load of outside air. Research has shown that some viruses are rendered inactive on surfaces when the ambient relative humidity was between 40%-60%.

Filtration

ASHRAE recommends using a minimum of MERV 13 filter to effectively trap viruses. This option is available on all sizes of rooftop equipment, and the standard backward-curved supply fans are capable of handling the additional static pressure associated with higher-quality filtration. AAON offers up to MERV 14 pleated air filters. HEPA final filtration is also available.

UV Lights

UV light options are available factory-installed and can be used to inactivate pathogens in the airstream of an air handling unit.

Precision Cooling and Heating Control

Innovative Permanent Magnet Motor Technology sets the RZ Series apart, featuring a hybrid motor with synchronous reluctance rotor and permanent magnets for efficiency surpassing IE5 standards. Variable speed compressors ensure precise cooling, while the system's heating capabilities offer flexibility with staged or modulating gas and electric heat. The addition of hot water or steam preheat coils enhances adaptability, positioning the RZ Series as a leading HVAC solution.

Permanent Magnet Motor Technology

The RZ Series supply fan array is designed around cutting-edge technology, including the option for permanent magnet motors. These hybrid motors incorporate a synchronous reluctance rotor with permanent magnets to achieve an International Efficiency rating above IE5, the highest level of efficiency today. The advantages of the Hybrid Permanent Magnet Motor are even more significant at lower fan speeds, due to the reduced load (RPM) where variable airflow fans will operate during a majority of the time. Another advantage is that this motor technology uses standard NEMA frames, providing more flexibility for replacement than proprietary designs.

Variable Speed Compressors

Variable speed compressors are quiet in operation and provide load-matching cooling and the highest efficiency ratings when operating at part-load conditions. Refrigeration controls are built into the AAON equipment to protect the compressors and optimize efficiency for single or multi-zone VAV (Variable Air Volume) and Makeup Air applications.

Precision Heating Control

AAON uses patented dimpled stainless steel or aluminized heat exchangers. Staging can be set up for on/off, two-stage, four-stage, modulating, or high turndown. Modulating gas heat provides greater fuel efficiency, longer heater life, and improved occupant comfort. SCR-controlled electric heat strips can be used for precise electric heating control without the need for gas piping.

Gas Heat

Ensure lasting performance with AAON's durable 304 stainless steel construction. The unique design eliminates the need for internal turbulators, reducing service issues and increasing capacity and efficiency. High turndown modulating gas heat enhances both fuel efficiency and occupant comfort. Individual gas heat exchanger modules are designed for 350 MBH and 400 MBH input rates and can be configured for up to a 4500 MBH total gas input rating on the largest cabinet size. RZ Series units allow for cartridge final filters. The option of direct-fire gas heat is available to improve energy efficiency, reduce fuel consumption, and lower operating costs.

Electric Heat

Electric resistance heating elements are open type with low watt density nickel chromium. Heating modules are 40 kW with individual circuit fusing and a manually reset high-temperature limit switch. SCR electric heat offers reduced power consumption, longer heater life, and improved occupant comfort.

Hot Water or Steam Preheat Coils

For certain jobsite conditions, coils are available to pre-condition outside air. 1 or 2-row hot water or steam coils may be supplied to match system requirements; hot water is also available in 4-row configurations.

Specifications

The RZ Series packaged rooftop provides comprehensive solutions, featuring air-cooled options spanning 45 to 240 tons and an evaporative-cooled range from 51 to 261 tons. Dimensions vary depending on options selected. All dimensions are in inches. Design cfm may be 30-50% greater or less than nominal cfm.