Nortek Global HVAC has added the R7DA, a combination dedicated outdoor air system (DOAS) and conventional space conditioning rooftop unit (RTU), to the Reznor® and Mammoth® branded R7 Platform product lines.
The R7DA is a direct expansion (DX) package DOAS/RTU offering a drop-in replacement that fits many existing RTU brand roof curbs. The product has a 1-inch-thick R-13 foam-insulated panel cabinet and a small footprint, making it suitable for new construction and retrofits.
The R7DA, which is available in 6 and 7.5 tons, complements the R7 Platform’s existing R7TQ package space conditioning (only) unit that’s available from 6 to 12.5 tons. The product line will be expanded to 20 tons in 2019.
The R7DA features a thermostat interface and DDC controller that provides pinpoint control by modulating EC motor supply fans, air-cooled DX, and gas heat. The DDC controller also uses proprietary algorithms to facilitate Nortek’s newly-patented method of modulating hot gas reheat circuits that eliminates inefficient evaporator freezing challenges common among all DOAS brands operating in cold weather.
The R7 Platform’s highly-configurable, field-convertible flexible design adapts to existing horizontal or vertical supply air discharge and return air without incurring the design costs of custom equipment. Electrical and gas piping inlets are possible through the curb or unit.
The R7DA also features airflow sensors that monitor static pressure to provide optimum cfms. Warranty is five years for DX parts and 10 years for the gas heat exchanger.