GENERAL AIRSTAGE CENTAURI R32 Central Heat Pump | 1.5 Tons - 18000 BTU

GENERAL AIRSTAGE CENTAURI AMUH18KUAS 18,000 BTU: the Central Heat Pump laid flat in a townhouse’s crawl space

Under the GENERAL AIRSTAGE label, the AMUH18KUAS air handler and the AOUH18KUAS1 outdoor unit form the system that also appears in our catalogue under the Fujitsu AIRSTAGE name. The manufacturer is the same; it has been called GENERAL Inc. since January 1, 2026. The manufacturer’s spec sheet does not change by a single comma, and neither does the warranty.

A townhouse leaves no wasted space. The basement is finished or too low, the closets are already in use, and the only free spot for a unit is often a crawl space or service void. That is where this unit’s multi-position design makes full sense: it installs horizontally, facing left or right depending on which side the ducts leave from, and it leaves the living space alone.

The other argument carries real weight in a place nobody goes: the built-in leak detection system. A unit you never see has to watch its own refrigerant circuit, and this one does it from the factory.

GENERAL or Fujitsu AIRSTAGE: the same machine

The story is short. Fujitsu General passed in August 2025 into the hands of Paloma Rheem Holdings, the group that has held Rheem since 1988; on January 1, 2026, the name GENERAL Inc. replaced the old one. Kawasaki, Japan, remains the head office and the home of the R&D centre, the factories keep producing, and the AIRSTAGE products keep their model numbers as well as their warranty program. The GENERAL brand itself is nothing new: it has been used since 1946 by a company founded in 1936, which in 2026 marks the 90th anniversary of its founding.

While the Fujitsu brand fades out gradually, the same machine is sold under both names. Rheem Canada has handled sales in Canada since February 2026, Groupe Master remains our distributor, and we keep both product pages online so the comparison happens in the open, value by value.

To see the twin page, follow this link: Fujitsu AIRSTAGE CENTAURI 1.5-ton (18,000 BTU).

The principle of a central heat pump is simple. The outdoor unit picks up or rejects heat, the air handler distributes it through the duct system, and a refrigerant line connects the two. In a townhouse, treated air leaves the service void toward the registers in each room, then comes back through the return air to the air handler’s plenum. Lying down, the 17.5 × 21 × 43 in. cabinet (width, depth, height) takes its 43 in. height horizontally; the clearance it needs depends on which side it rests on, and we measure it on site, counting room to work and to reach the filter.

If the crawl space turns out to be too low or too damp, the unit is not ruled out. It also mounts upflow in a closet, or downflow with the UTD-DFMSB1 kit. Better to change positions than force an installation that will complicate every service call.

In the horizontal position, a few points need special attention, and we settle them before installation:

• the condensate drain, which must flow freely from the unit lying on its side;
• an access panel that truly gives access to the filter and the service panels;
• the duct layout around joists and party walls;
• the path of the refrigerant line, cable and drain to the outdoor unit.

Maximum airflow reaches 600 CFM, and the air handler accepts an external static pressure of 0.08 to 0.80 in. WC. That range shows how hard the blower can push through ducts that work around the structure; we measure existing ducts before reusing them, and the number of registers is decided during the visit.

On efficiency, the manufacturer’s spec sheet shows a SEER2 of 19.2, an HSPF2 of 10.5 and an EER2 of 12.2, under AHRI certificate 217290593. The system is ENERGY STAR certified, cold climate category (ID 4428946). Nominal cooling capacity is 18,000 BTU, modulated from 3,100 to 20,100 BTU by the Inverter compressor; in heating, the rated value is 21,600 BTU at 8.3 °C, over a range of 3,100 to 24,000 BTU. Dehumidification is 2.37 pints per hour.

For winter, the manufacturer publishes two measurements from test conditions that cannot be compared: at −8 °C, 16,100 BTU and a COP of 2.91; at −15 °C, 17,300 BTU and a COP of 2.4. The R-32 outdoor unit keeps heating down to −21 °C according to the manufacturer’s range, with no low-temperature shutdown according to the brochure. Beyond what the heat pump delivers, the air handler calls on backup heat through one of its built-in logics, with the manufacturer’s compatible electric kit, sold separately and fed by its own circuit.

Noise is mostly managed outside. Under the floor, the air handler runs at 33 dB(A) at its lowest and 44 dB(A) at its highest. The outdoor unit is rated at 55.0 dB(A), and in a row of houses the neighbour is never far: we choose the location of the pad or bracket with their patio and windows in mind as much as yours.

Between the two units, the allowed refrigerant line runs from 16 ft (5 m) to 98 ft (30 m), the precharge covers the first 66 ft (20 m), and the height difference must not exceed 49 ft (15 m). Piping is 1/4 and 1/2 in. The connection is 208/230 V, with an MCA of 18 A and an MOP of 20 A. A refrigeration technician handles commissioning.

Since the unit is hidden, the control becomes the everyday interface. None is supplied by default; you choose among:

• Wi-Fi through the AIRSTAGE Mobile app, handy for keeping an eye on the unit without going down to see it;
• a KAGAMI UTY-RVRU or UTY-RNRUZ5 wired controller on a living-area wall, with compatible controllers also giving access to service monitoring;
• a third-party 24 V thermostat through the UTY-TTRXZ1 interface, or the IR receiver kit with wireless remote.

The built-in input/output terminals also let you connect an HRV or ERV, a humidifier, a fire alarm or a door switch; BACnet and Modbus exist for building management, of little use in a home. Day to day, maintenance is limited to the filter, which you reach through the access panel; the manufacturer offers an optional 16 × 20 in. filter base.

This system is listed for the Hydro-Québec LogisVert grant at $1,932, according to the October 27, 2026 list. Manufacturer’s warranty: 12 years for the compressor, the same for parts, 6 years for labour. The manufacturer’s spec sheet, in its GENERAL version prepared by AirGreen in French and English, comes with the product for performance data and dimensioned drawings.

It suits a mid-size townhouse or semi-detached house, already fitted with ducts or ready to receive them, where the unit only finds room lying flat. For a large house on three levels, we will check whether a larger capacity from the series is a better fit.

Otterburn Park and the South Shore: your free quote

In Otterburn Park, we start by opening the hatch: measuring the crawl space, checking the ducts, placing the outdoor unit with the neighbours in mind. You then receive a free quote that is clear about what is included. Our HVAC services also cover Montreal, Laval, Longueuil and the North Shore, on top of the whole South Shore, and AirGreen works there as an AIRSTAGE Elite Plus installer.

To book the visit, call 514 316-2973.