Air to Water Heat Pump - Nordic ATW25 - Split Type - 2 Tons Nominal Cooling Capacity

System Overview

The Nordic ATW Series (introduced in 2015) is an air-source heat pump designed for hydronic heating and cooling. Instead of using a geothermal ground loop, it exchanges heat with outdoor air. It’s a split system, which is unusual for this category, with an outdoor unit (coil, fan, expansion valve, sensor) and an indoor unit (compressor, electronics, controls).

Applications

• In-floor radiant heating

• Low-temperature radiators

• Domestic hot water pre-heating (via indirect tank with hydronic coil)

• Hydronic air handlers (for heating & cooling distribution)

Operation & Controls

• Heats or cools a buffer tank to a user-defined setpoint.

• Zones receive conditioned water via zone valves/pumps.

• Optional dual buffer tanks allow for heating & cooling availability.

• Control options:

  • Built-in routines (default buffer tank temperature management)

  • BACnet integration

  • External aquastat (optional)

• Controlled by the GEN2 programmable board with:

  • Laptop connectivity (via free PC App)

  • Data logging & graphing

  • Real-time monitoring of electronic sensors

Domestic Hot Water Support

• Integrated double-wall desuperheater

• Provides ~5% of heat pump capacity to pre-heat DHW

• Operates only during space heating/cooling cycles

• Safe for potable water since lines are indoors (no freeze risk)

Design & Components

• Compressor: Two-stage scroll

• Outdoor coil: E-coated (corrosion resistant)

• Hydronic heat exchanger: Copper/steel coaxial (CuNi optional)

• Cabinet: Galvanized, powder-coated steel

• Electronics: Protected indoors for longevity

Advantages

• Minimal outdoor servicing (critical parts are indoors)

• No antifreeze required in the water loop

• No compressor heater needed

• Longevity & reliability (components in conditioned space)

• Direct potable water heating possible (via desuperheater)