Options

A full range of factory-installed modular options are available on standard ship cycles, allowing your rooftop design to be best suited to each individual application.

Cooling Only/Heating Casings

• Cooling Only — Two casing choices are available, one designed for high airside efficiency and one for sound sensitive applications. The 90 through 130 ton are extended casing only.
• Electric Heat — Nickel-chromium electric heating elements in individually fused circuits of 48 amps or less and with all necessary safeties. A full range of sizing options is available.
• Natural Gas Heat -- Two Stage and Limited Modulation — Two-pass stainless steel tubular free floating heat exchanger has industrial type burner and combustion blower. Available with high or low fire and UL or CSA approval.
• Natural Gas Heat - Full Modulation — The heat exchanger drum, tubes and front and rear headers are constructed of the most corrosion resistant austenitic stainless steel alloys available.
• Steam Heat — ARI certified type NS coil with non-freeze steam distribution. Coils are pitched for drainage and are provided with steam modulating valve with actuator. High and low heat options are available.
• Hot Water Heat — ARI certified type W coil mounted for drainage and provided with hot water modulating valve with actuator. High and low heat options are available.

Power Supplies

Rooftops are available with 200, 230, 460 and 575 voltage power supplies.

Exhaust

• No Exhaust — Rooftops can be built for makeup air applications with no exhaust. Relief opening is sealed watertight.
• Barometric Relief — Gravity dampers are provided that open to relieve positive pressure.
• 50 Percent Exhaust Fan — One double inlet forward-curved fan can exhaust up to 50 percent of supply air. Control is on/off based on economizer damper position. Barometric dampers at fan outlet prevent air backdraft.
• 100 Percent Modulating Exhaust Fan — Two double inlet forward-curved fans can exhaust up to 100 percent supply air. Fans operate when economizer damper is open greater than minimum position. Discharge dampers at fan outlet modulate in response toeconomizer damper position on CV rooftops.
• 100 Percent Modulating Exhaust with Statitrac™ Control — For both CV and VAV rooftops, the 100 percent modulating exhaust discharge dampers are modulated in response to building pressure. A differential pressure control system, called Statitrac™, uses a differential pressure transducer to compare indoor building pressure to atmospheric pressure. The FC exhaust fan is turned on when required to lower building static pressure to setpoint. The Statitrac control system then modulates the discharge dampers to control the building pressure to within the adjustable, specified dead band that is set at the Human Interface Panel.

Filters

• No Filters (two inch throwaway filter rack only) — complete set of two-inch thick filter racks, without the filter media to accommodate applications which require field supplied filters.
• No Filters (bag/cartridge with prefilter filter rack) — long-lasting galvanized steel frame without the filter media to accommodate applications which require field supplied filters.
• Throwaway — Two-inch, 30 percent efficient throwaway filters, includes rack as standard.
• Cleanable Wire Mesh — Two-inch permanent washable wire mesh filters are provided with metal frame.
• High-Efficiency Throwaway — Two inch throwaway filters include rack and have an average arrestance in excess of 90 percent when tested in accordance with ASHRAE 52-76.
• 90-95 Percent Bag Filter (with prefilter) — Glass fiber extended media bag filter is mounted in a galvanized steel frame. 90-95 percent dust spot efficiency. Two-inch throwaway prefilters are included with this option.
• 90-95 Percent Cartridge Filter (with prefilter) — These twelve-inch deep cartridge filters are mounted in a galvanized steel frame. They are Class 1 listed by Underwriters Laboratories and have a 90-95 percent dust spot efficiency per ASHRAE 52-76. To ensure maximum cartridge filter life, two-inch prefilters are included.

Fresh Air

• 0 Through 25 Percent Manual Outside Air — Includes outside air opening with moisture eliminator and manually positioned damper for drawing up to 25 percent outside air. (20-75 tons only)
• Economizer — Includes the primary temperature controls necessary to automatically use outdoor air for free cooling. Option includes modulating return and outside air dampers, enthalpy lockout, minimum position control and spring return motor. It is provided with standard low leak outside air dampers with a leakage rate of 2.5 percent of nominal airflow at one inch W.C. static pressure.

System Control

• Constant Volume — Provided with all the necessary controls to operate rooftop from a zone sensor, including CV microprocessor unit control module, a microprocessor compressor controller and a unit mounted Human Interface Panel.
• VAV Supply Air Temperature control without inlet guide vanes — Provided with all the necessary controls to operate a VAV rooftop from the discharge air temperature, including discharge air microprocessor controller and discharge air sensor. The microprocessor controller coordinates the economizer control and the stages of cooling with zone or outdoor air reset capabilities and an adjustable control band to fine-tune the control to specific applications.
• VAV Supply Air Temperature control with inlet guide vanes — Provided with all the necessary controls to control/ operate a VAV rooftop from the discharge air temperature, including a discharge air microprocessor controller, a discharge air sensor, pressure sensor and inlet guide vanes. The microprocessor controller coordinates the economizer control and the stages of cooling with zone or outdoor air reset capabilities and an adjustable control band to fine-tune the control to specific applications. The inlet guide vanes are used with VAV rooftops to control duct static pressure. Option includes vanes and static pressure controls. Forward-curved fans with inlet vanes are the most efficient way to mechanically modulate airflow.
• Exhaust Fan Variable Frequency Drives w/o Bypass (with Statitrac Only) — Provided with all the necessary controls to control/maintain building space pressure through a CV or VAV rooftop. The Variable Frequency Drive (VFD) modulates the speed of the exhaust fan motor in response to building pressure. A differential