The Nordic AHW-series and AH4P-series are ducted hydronic air handlers (fan coils) that can transfer the heating or cooling effect from heated or chilled water into air in a forced air duct system. The duct system of the air handler can be zoned, or more commonly comprises one zone of a larger zoned heating/cooling/dehumidification system.
Being an air handler without its own heated or chilled source, the 2-pipe AHW-series does require one indoor water loop. This loop can be seasonally switched between heated and chilled to perform heating or cooling duty.
Similarly, the AH4P-series is a 4-pipe version that requires both heated and chilled indoor hydronic loops, for installations where both are always available. In this way, both heating and cooling are always instantly available, and also dehumidification can be performed.
Both the AHW and AH4P are available in one model size (65), which can be modulated over a very large capacity range by varying the airflow and water flow. Both vertical and horizontal versions are available, in 115-1-60 or 208/230-1-60 electrical service.
The AHW-series has provision for an internal electric plenum heater, which can be ordered as an accessory. If a plenum heater is required with the AH4P-series, it is placed outside the unit in the discharge ductwork.
The room thermostat or zone controller calls for either one selectable airflow, or one of five airflows, from 900-2300 cfm. If the –VSP option is ordered, it is also possible for the thermostat or controller to use a 0-10VDC signal to request any airflow from 0-2500 cfm (see next section).
The blower motor is a premium constant-airflow ECM, which delivers the selected air flow regardless of back pressure from the duct system or air filter. The cabinet is constructed from powder coated galvanized sheet metal and is fully insulated with fiberglass insulation.
The handler can be ordered in a vertical or horizontal configuration from the factory.
The 2-pipe AHW or 4-pipe AH4P should also be correctly specified at time of order.
Each model can be ordered with 24VAC control, in which case 5 discreet airflows are available for activation by the thermostat or control system; or continuously variable airflow (AHW-65-VSP) in which the external thermostat or controller sends a 0-10VDC signal to select any airflow from 0 to 2500 cfm.
See the above Manual for complete model numbers and complete application and installation advice.