GENERAL AIRSTAGE Centauri Heat Pump | Ceiling Suspended System | 18000 BTU

GENERAL AIRSTAGE ABUH18KUAS Ceiling-Suspended Heat Pump, 18,000 BTU: cold-climate heating under a ceiling that won’t take a cassette

The GENERAL AIRSTAGE Centauri 18,000 BTU heat pump pairs the ABUH18KUAS indoor unit with the AOUH18KUAS1 outdoor unit. These are exactly the two units of the twin Fujitsu AIRSTAGE system: same factory, same model numbers, same AHRI certificate, same ENERGY STAR certification, same warranty. Only one thing has changed, the manufacturer’s name. Fujitsu General Limited has been called GENERAL Inc. since January 1, 2026.

This unit answers a common situation in commercial spaces: a concrete ceiling, or drywall screwed directly under the structure, with no clearance at all above it. A cassette needs that space to be recessed, and it simply isn’t there. The Centauri unit doesn’t try to disappear into the ceiling. It mounts underneath, in plain view, and it stands only 9.25 in high.

The other argument is winter. The system is built for a cold climate: it heats down to −21 °C outdoors, and the manufacturer’s brochure states that it has no low-temperature shut-off device. For a Chomedey business that has to be comfortable from opening time on a January morning, that is exactly what you want to read on a spec sheet.

GENERAL or Fujitsu AIRSTAGE: the same machine

Paloma Rheem Holdings, owner of Rheem since 1988, acquired Fujitsu General Limited in August 2025. On January 1, 2026, the company became GENERAL Inc. Its head office and its research and development centre stayed in Kawasaki, Japan, the factories did not change and the AIRSTAGE line keeps its model numbers. The Fujitsu brand is being phased out gradually; during the transition, the same machine is sold under both names.

That is why we publish both product pages side by side. Some customers still look for Fujitsu, others already see GENERAL on the box, and the table below lines up identical values, row by row. In Canada, Rheem Canada has handled sales since February 2026, and Groupe Master remains our distributor. AirGreen installs these units as an AIRSTAGE Elite Plus installer.

The Fujitsu version stays online, with exactly the same data: Fujitsu AIRSTAGE Centauri 18,000 BTU ceiling-suspended page.

Back to the commercial space. A ceiling with no clearance rules out a cassette, and often a central system too, for lack of room for ducts. That leaves the walls, but in a store, the walls are working: shelving, displays, counter, signage. The ceiling-suspended unit takes over a strip of ceiling nobody uses, and the air leaves from up there, above people’s heads, rather than at the height of a customer standing in front of a shelf.

The certified values come from NEEP, based on AHRI certificate 215434548. Here is how to read them:

• at −8 °C, the nominal heating capacity is 14,400 BTU, with a COP of 2.91: the machine returns as heat 2.91 times the electricity it consumes;
• at the NEEP test point of −15 °C, the published value is 17,100 BTU, with a COP of 2.26;
• at −21 °C, the coldest certified point, NEEP lists 14,400 BTU and a COP of 2.04;
• in cooling, SEER2 reaches 23.4 and EER2 12.9; for seasonal heating, HSPF2 is 11.2.

These figures come from separate test points: each one reads on its own, with no calculation from one to the other. The manufacturer also states that the system can deliver up to 20% more heat than its labelled nominal capacity. For nights that drop below −21 °C, the system’s external inputs can control backup heating, a precaution we recommend in a space where nothing may freeze.

In a shop, you talk with customers, and noise matters. The indoor unit runs between 31 and 38 dB(A), and its fan offers four speeds plus an Auto mode. The compact outdoor unit is rated at 55.0 dB(A) and has a quiet mode, valuable when it sits in a back lane, under the window of a neighbouring apartment. Airflow reaches 494 CFM, distributed from the ceiling.

The route between the two units is planned before the work begins. It includes the refrigerant line (1/4 in and 1/2 in piping), the power cable and the drain. For this 18,000 BTU model, the line can reach 30 m (98 ft) with a maximum height difference of 15 m (49 ft), and the outdoor unit is precharged for 20 m (66 ft). In a unit within a row of storefronts, that length leaves room to exit through the back of the building. The outdoor unit sits on a base or a bracket, and it is a refrigeration technician who puts the system into service.

For condensate, water drains by gravity when the slope allows; otherwise, an optional drain pump takes over. The chosen route is spelled out in black and white in the quote. On the electrical side, the system runs on 208/230 V, with a minimum circuit ampacity (MCA) of 15 A and a maximum overcurrent protection (MOP) of 20 A, the values the electrician needs to prepare the circuit.

No controller comes with this system as standard. It is chosen according to how the space is run:

• a wired touchscreen controller, UTY-RNRUZ5 or KAGAMI UTY-RVRU, installed near the counter or in the back room;
• a simple wired controller, if staff only touch the basics;
• the IR receiver kit with the UTY-LBTUH wireless remote, sold separately;
• the UTY-TFSXJ4 Wi-Fi adapter, to adjust the temperature from the AIRSTAGE Mobile app before opening;
• a 24 V thermostat interface, when an existing thermostat has to stay in place.

The manufacturer’s modes follow the rhythm of a business well. Economy mode moderates consumption during quiet hours, minimum heat keeps the space tempered once the doors are closed, powerful mode brings the temperature up fast on a freezing morning, and auto restart starts the unit again after a power outage. Defrosting, for its part, happens on its own.

The indoor unit’s ProCore copper coils offer high corrosion resistance. R-32 refrigerant has a global warming potential about 68% lower than that of R-410A, and the system holds less of it. Routine maintenance mostly comes down to the indoor unit’s filters: we show staff how to clean them, to keep airflow at the intended level.

The model is ENERGY STAR certified, recognized as cold climate, and listed on Hydro-Québec’s LogisVert list of October 27, 2026 for a grant of $1,728. For a commercial space, we check your building’s eligibility at the quote stage, before counting on that amount. The warranty does not change from one brand to the other: 12 years on the compressor, 12 years on parts, 6 years on labour.

This system is aimed first at neighbourhood shops, offices, salons and small clinics whose ceiling cannot take a cassette and whose walls are already in use. It also suits any space that has to be heated seriously in winter and cooled in summer by a single unit, with no ceiling work.

Your commercial space in Chomedey (Laval): free quote

Call AirGreen at 514 316-2973 for a free quote. We look with you at the type of ceiling, the outdoor unit location, the drain route and the controller that suits your team, then we price the complete installation of the 18,000 BTU Centauri.

Our HVAC team serves Montreal, Laval, Longueuil, the North Shore and the South Shore, with the same units under the GENERAL AIRSTAGE or Fujitsu AIRSTAGE name. If another solution suits your space better, we will tell you frankly.