GENERAL AIRSTAGE CENTAURI R32 Central Heat Pump | 4 Tons - 48000 BTU
GENERAL AIRSTAGE CENTAURI AMUH48KUAS 48,000 BTU Central Heat Pump: one system for the whole large house
Under the GENERAL AIRSTAGE name, the AMUH48KUAS air handler and the AOUH48KUAS1 outdoor unit make up exactly the same system as their twin, the Fujitsu AIRSTAGE CENTAURI 4-ton central heat pump. The manufacturer is the same: Fujitsu General Limited was renamed GENERAL Inc. on January 1, 2026. The manufacturer's spec sheet is the same, and so is the warranty.
This size is meant for the large house you want to heat and cool entirely with one system: a central heat pump, a compatible electric backup heat kit and the wall thermostat you already know how to use. One unit in the basement, one unit outside, one control on the wall.
An honest word about the numbers. The name says 48,000 BTU, but the manufacturer's brochure gives 45,500 BTU of rated cooling, over a range of 15,400 to 48,000 BTU. For heating, it lists 51,000 BTU rated at 8.3 °C, with the range running from 16,000 to 55,000 BTU. Better to read these values here than to discover them later.
GENERAL or Fujitsu AIRSTAGE: the same machine
Owner and name changed at the Japanese manufacturer, not the products. Paloma Rheem Holdings acquired it in August 2025, and the AIRSTAGE model numbers, the factories and the warranty program stayed intact. On the Canadian side, Rheem Canada has handled sales since February 2026; our distributor, for its part, is still Groupe Master, so the system reaches us through the same channel as before.
Until the Fujitsu brand fades out, the same machine is sold under two names. That is why both pages coexist on our site, with a line-by-line comparison table.
| Specification | GENERAL AIRSTAGE | Fujitsu AIRSTAGE |
|---|---|---|
| Indoor unit | AMUH48KUAS | AMUH48KUAS |
| Outdoor unit | AOUH48KUAS1 | AOUH48KUAS1 |
| AHRI certificate | 217290597 | 217290597 |
| Nominal capacity | 48,000 BTU | 48,000 BTU |
| Refrigerant | R-32 | R-32 |
| Power supply | 208/230 V | 208/230 V |
| SEER2 | 17.0 | 17.0 |
| HSPF2 | 9.6 | 9.6 |
| EER2 | 9.5 | 9.5 |
| Heating capacity at −8 °C | 37,200 BTU | 37,200 BTU |
| COP at −8 °C | 2.99 | 2.99 |
| Heating capacity at −15 °C | 41,000 BTU | 41,000 BTU |
| COP at −15 °C | 2.24 | 2.24 |
| Heating down to (manufacturer operating range) | −21 °C | −21 °C |
| ENERGY STAR | Yes | Yes |
| Cold climate (ENERGY STAR) | Yes | Yes |
| ENERGY STAR ID | 4428950 | 4428950 |
| Indoor unit dimensions (W × D × H, in) | 21 x 21 x 48 | 21 x 21 x 48 |
| Outdoor unit dimensions (W × D × H, in) | 31 x 12.63 x 37 | 31 x 12.63 x 37 |
| Indoor sound level (min / max) | 34 / 51 dB(A) | 34 / 51 dB(A) |
| Outdoor sound level | 59.0 dB(A) | 59.0 dB(A) |
| Airflow | 1,600 CFM | 1,600 CFM |
| Dehumidification | 4.7 pints/h | 4.7 pints/h |
| Wi-Fi | Optional | Optional |
| LogisVert grant (Hydro-Québec, list of October 27, 2026) | $4,464 | $4,464 |
| Warranty (compressor · parts · labour, years) | 12 · 12 · 6 | 12 · 12 · 6 |
| Manufacturer | GENERAL Inc. (Kawasaki, Japan) | GENERAL Inc. (Kawasaki, Japan) |
| Product page | This page | Fujitsu AIRSTAGE CENTAURI 48,000 BTU |
To see the Fujitsu version, identical down to the last figure: Fujitsu AIRSTAGE CENTAURI 48,000 BTU central heat pump.
In a large house, everything comes down to the duct system. With 1,600 CFM of maximum airflow and external static pressure of between 0.2 and 0.8 in. WC, the AMUH48KUAS has what it takes to serve rooms far from the mechanical room. The ducts still have to keep up, though. A network sized long ago for a small furnace won't carry that much airflow without whistling at the grilles. That is why the network gets a close look at the visit: that is where the layout, the number of grilles and the return air openings are decided.
The unit's cabinet is 21 × 21 × 48 in. (W × D × H). Being multi-position, it stands upright in the basement for upflow, goes downflow with the UTD-DFMMB1 kit, or lies horizontal in a finished attic or a crawl space, left side or right side. An access panel is planned in every case for the filter and maintenance.
Now, the thermostat. Many owners of large houses are attached to the wall control they know. The UTY-TTRXZ1 interface makes it possible to connect a third-party 24 V thermostat to the unit. One condition: that thermostat has to be able to control a heat pump and its backup. We check the model at the visit and, if it isn't suitable, you know before you sign. The system comes without a control; here are the options available:
- a third-party 24 V thermostat, through the UTY-TTRXZ1 interface;
- a KAGAMI UTY-RVRU or UTY-RNRUZ5 wired controller;
- the AIRSTAGE Mobile app, over Wi-Fi;
- a wireless remote, with the IR receiver kit;
- BACnet or Modbus, if the property is tied to a building management system.
A compatible controller also opens the door to service monitoring, handy when a single machine carries the whole house.
Heating the whole house with one system also means planning the backup carefully. The unit can follow several backup logics, and the manufacturer offers compatible electric kits that are bought separately and require a dedicated circuit. The heat pump, for its part, needs its own 208/230 V circuit (MCA 30 A, MOP 30 A). These two loads add up: we look at your electrical panel's capacity before proposing anything.
Down to −21 °C, the AOUH48KUAS1 heats and cools, and the brochure speaks of "no lockout" when it is cold. Below that, the backup kit takes over. For the whole series, the manufacturer claims up to 33% of rated heating above nominal capacity. The certification file provides two different test points, shown as they are: 37,200 BTU (COP 2.99) at −8 °C and 41,000 BTU (COP 2.24) at −15 °C. Its ratings: SEER2 17.0, HSPF2 9.6 and EER2 9.5 (AHRI certificate 217290597), with an Inverter compressor and R-32 refrigerant, whose global warming potential is low.
The air handler stays at 34 dB(A) at low speed and reaches 51 dB(A) at full airflow. The AOUH48KUAS1 unit, at 31 × 12.63 × 37 in., is rated at 59 dB(A): we pick a side of the house where it won't bother the patio or the neighbours. In a large house, it sometimes ends up far from the mechanical room, and that is where the refrigerant line (3/8 and 5/8 in.) matters. It accepts up to 75 m (246 ft) of length, the precharge covers 30 m (98 ft) of it, it needs at least 5 m (16 ft) and the height gap between the two units tops out at 30 m (98 ft). Beyond the precharge, the refrigeration technician adds the required refrigerant at commissioning.
In humid weather, the spec sheet lists 4.7 pints/h of dehumidification. For maintenance, a 20 × 20 in. filter base is among the options; with that much airflow, a clogged filter shows up fast, so keep a spare on hand. The leak detection system is built into the unit.
On the grant side, this is the most generous size in the CENTAURI series: Hydro-Québec's LogisVert list, in its October 27, 2026 version, gives it $4,464; if the list changes before you apply, the new version is the one that applies. It also holds ENERGY STAR cold climate certification (ID 4428950). Warranty: compressor and parts 12 years, labour 6 years.
The ideal profile: a large house where every room already gets its air from the duct system. If a whole wing is poorly served by the current network, a single system may not be the right answer, and the duct layout shows it quickly. AirGreen, an HVAC contractor that holds AIRSTAGE Elite Plus installer status, makes that call at the visit.
A free quote in Îles-Laval and everywhere in Laval
We install this 4-ton system in Îles-Laval and the other neighbourhoods of Laval, as well as in Longueuil, Montreal, on the South Shore and on the North Shore. For your free quote, the number is 514 316-2973: we will come to see the mechanical room, the duct system, the electrical panel and the spot for the outdoor unit.
Before you call, take a photo of your current thermostat and of the label on your heating unit. Those two pictures already give us a good idea of compatibility with the 24 V interface.