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Wall-mounted or ceiling cassette for an open-plan area
In an open-plan area, the real question is where the air starts from. The wall-mounted unit blows from a wall, forward. The cassette is recessed into the ceiling and blows on all four sides. One needs a clear section of wall, the other a void above the ceiling. Two 12,000 BTU FUJITSU AIRSTAGE units serve as examples, each with its own AHRI certificate.
ORION XLTH · 12,000 BTU
ASUH12KZAS / AOUH12KZAH1 · AHRI 214888802
View the product page
CENTAURI ACUH12KUAS · 12,000 BTU
ACUH12KUAS / AOUH12KUAS1 · AHRI 215434546
View the product pageWhat the electricity costs, in dollars, winter and summer
AirGreen estimate for the same 12,000 BTU/h zone in Montréal, at Hydro-Québec Rate D, taxes included. Both heat pumps are calculated exactly the same way, with the same method as on all our comparison pages; only their certified efficiencies change. Each example has its own outdoor unit and certificate: the difference comes from these two combinations, not only from being on the wall or in the ceiling. Electric baseboards serve as the reference point.
How this amount is calculated
- Heat needed over the winter. A zone whose heat loss reaches 12,000 BTU/h ( kW) at −23.1 °C, the Montréal design temperature: kW × 24 h × 4,167 degree-days ÷ (18 − (−23.1)) = kWh of heat for 24-hour heating, all winter long. Heating degree-days (base 18 °C) and design temperature: Natural Resources Canada, HOT2000 climate data, Montréal Intl station. With fewer hours per day (“Heating” slider), the heat is reduced in the same proportion, for the heat pump and the baseboards alike: this is a simplification that does not account for recovery after a temperature setback.
- Electricity for heating. Heat pump: heat × 3.412 ÷ HSPF2 region V, the AHRI certificate value published by NEEP. Region V is the coldest in the standard, and its calculation includes the electric backup expected when the heat pump is no longer enough. Electric baseboards: 1 kWh of electricity for 1 kWh of heat.
- Electricity for cooling. 12,000 BTU/h ÷ SEER2 × hours per day × 60 days ÷ 1,000: the method of Hydro-Québec’s air-conditioning calculator, with the SEER2 seasonal efficiency from the AHRI certificate. The number of hours is a scenario, adjustable above from 1 to 24 h. At 24 h, the calculation assumes rated capacity all day: this is a maximum, since a variable-speed unit slows down once the room is at the right temperature.
- Price. Hydro-Québec Rate D in effect April 1, 2026: 7.065 ¢ per kWh up to 40 kWh per day, 11.142 ¢ above that; the average price, 9.104 ¢, is the one Hydro-Québec’s calculators use. GST and QST included. The grid access charge, the same with or without a heat pump, is not counted.
AirGreen method v1.1, November 9, 2026. An estimate is used to compare units under the same conditions. Your actual bill depends on the house, insulation, settings and use; this amount is not a promise.
One airflow forward, or four to the sides
A kitchen, a dining room and a living room in a single space, seen from above. Choose the unit, the shape of the room and, for the cassette, its position in the ceiling. The drawing shows the air directions described by FUJITSU AIRSTAGE; it does not measure a throw distance.
ORION XLTH wall-mounted unit
ACUH12KUAS cassette
The cassette hides in the ceiling
The body of the example cassette is 245 mm high with a 570 × 570 mm footprint, according to the submittal. Move the slider to the free height measured in your home, between the finished ceiling and the structure above: the drawing compares to scale.
The free height in your home
In the drawing, the grey band at the top is the structure above (joists or slab). The installation manual adds clearances around the body and specifies how it is suspended; the grille (UTG-CCGFGA, sold separately) fits a standard suspended grid ceiling, according to the submittal. The wall-mounted unit does not use this space.
Six differences, one after another
Both heat and cool. The difference is in the path the air takes, the space they need, the condensate water and maintenance.
Below −15 °C: every published figure, at its exact temperature
NEEP measures both examples at −15 °C. Lower down, the cassette is measured at −20.6 °C (−5 °F), the bottom of its stated range, and the wall-mounted unit at −26.1 °C (−15 °F). Each value is placed at its temperature, with its source; nothing is calculated between two points.
Percentages of the 12,000 BTU/h rated capacity published by FUJITSU AIRSTAGE (brochure FG8153C, rev. 4/2025), outside the certificate; dark line: 100%. The cassette’s submittal does not publish an equivalent percentage.
What FUJITSU AIRSTAGE states about each one
Based on the wall-mounted unit’s brochure and the cassette’s submittal. When a document says nothing, the card says so.
Wall-mounted: blows forward from the wall.
Cassette: outlets on four sides; UTR-YDZB blanking plate available as an accessory to close one outlet.
Wall-mounted: wireless remote included; built-in Wi-Fi, AIRSTAGE Mobile app.
Cassette: optional wireless remote (UTY-LNTU); optional Wi-Fi; BACnet and Modbus.
Wall-mounted: not indicated in the brochure; the drain follows the piping.
Cassette: built-in drain pump, according to the submittal.
Wall-mounted: not applicable.
Cassette: UTG-CCGFGA grille sold separately; it fits a standard suspended grid ceiling.
Wall-mounted: Economy, Energy Saving, Powerful, Minimum Heat, Occupancy.
Cassette: Economy, Energy Saving, Powerful, Minimum Heat; weekly and 24-hour timer, sleep mode.
Wall-mounted: not indicated in the documents consulted.
Cassette: UTZ-VXAA fresh-air kit and high-humidity insulation kit available as accessories.
How loud each one is, according to FUJITSU AIRSTAGE
The manufacturer measures both indoor units in an anechoic chamber, at each speed. The wall-mounted unit blows from the wall; the cassette, from the ceiling, above people’s heads.
How to read these figures. dB(A) measures a noise level as the ear perceives it: the lower the number, the quieter the unit. Each dot is a published fan speed.
Why this is not a ranking. The cassette’s submittal states that a real installation can be louder than the laboratory measurement. Position in the room matters as much as the figure.
Indoor units, in cooling
Published sound pressure, manufacturer’s anechoic chamber
Outdoor units, outside
Published sound pressure
Measurements taken by each manufacturer using its own method; here, the same manufacturer for both. Read them as reference points, not as a ranking.
What shows in the room, at the same scale
The wall-mounted unit shows its whole front; the cassette shows only its grille in the ceiling, but its whole body is above.
Width, at the same scale
Width to scale: 1,000 mm = the full width of the photo area. The cassette photo is in perspective, with its grille; the dimension shows the published body footprint.
| Installation | ORION XLTH wall-mounted unit | ACUH12KUAS cassette |
|---|---|---|
| Indoor unit W × H × D, weight | 38 9/16 × 11 × 9 7/16 in, 28 lb | 22 7/16 × 9 5/8 × 22 7/16 in, 33 lbBody, without the grille |
| Maximum piping length | 82 ft | 98 ft |
| Precharged length | 49 ft | 66 ft |
| Maximum height difference | 66 ft | 49 ft |
| Liquid – gas diameters | 1/4 – 3/8 in | 1/4 – 3/8 in |
| Outdoor unit W × H × D, weight | 31 7/16 × 24 7/8 × 11 7/16 in, 86 lb | 31 7/16 × 24 7/8 × 11 7/16 in, 84 lb |
| Electrical protectionPer the manufacturer | 15 A breaker | Max. 15 A breaker (MCA 14.2 A) |
| Dehumidification | 1.9 L/h | 1.2 L/h |
| Stated heating / cooling range | −26 to 24 °C / −10 to 50 °C | −21 to 24 °C / −21 to 50 °C |
Sources: FUJITSU AIRSTAGE ORION XLTH brochure FG8153C (rev. 4/2025) and technical manual DR_AS233ES_02 for the wall-mounted unit; FUJITSU AIRSTAGE submittal 12KUBS1C (version 20260707A) for the cassette. This submittal describes the cassette with the AOUH12KUBS1 outdoor unit, whose certificate (217734521) carries the same SEER2, EER2 and HSPF2 values as that of the example sold by AirGreen (AOUH12KUAS1, 215434546). Dimensions published as height × width × depth: 245 × 570 × 570 mm for the cassette body.
What people ask us about wall-mounted units and cassettes
Is a cassette possible in a condo?
It all depends on the ceiling. Under a concrete slab with no suspended ceiling, the 245 mm body has no room; with a deep enough suspended ceiling, recessing becomes possible. The condominium by-laws may also govern the work.
Why does the cassette have a pump?
Because condensate water forms in the ceiling, far from a drain. The example’s submittal indicates a built-in drain pump.
Is the grille included?
In the example, the UTG-CCGFGA grille is sold separately, according to the submittal. The quote should say so.
Can one of the four air outlets be closed?
Yes, with the UTR-YDZB blanking plate available as an accessory, for example when the cassette is near a wall. The “3-way” diagram above shows this case.
Which one heats down to the lowest temperature in winter?
For these two examples, the wall-mounted unit is certified down to −26.1 °C and the cassette down to −20.6 °C, each at the bottom of its stated range. These are two different combinations: the same cassette exists with an XLTH outdoor unit, under another certificate.
Is a step ladder needed for maintenance?
For the cassette, yes: the filter is behind the ceiling grille. For the wall-mounted unit, it is behind the front panel, at wall height.
All AHRI and NEEP values for both examples
| Certified value | ORION XLTH wall-mounted unit | ACUH12KUAS cassette |
|---|---|---|
| Cooling | ||
| Rated capacity at 35 °C | 12,000 BTU/h | 12,000 BTU/h |
| SEER2 | 30.5 | 23.7 |
| EER2 | 16 | 14.1 |
| Heating, same conditions | ||
| HSPF2 region IV / V | 12.7 / 10.1 | 11.5 / 9.2 |
| 8.3 °C: min. / rated / max.BTU/h | 3,500 / 16,000 / 23,600 | 3,100 / 16,000 / 19,400 |
| 8.3 °C: COP min. / rated / max. | 5.13 / 4.64 / 3.07 | 4.33 / 3.61 / 2.81 |
| −8.3 °C: min. / rated / max.BTU/h | 2,200 / 10,000 / 18,700 | 2,300 / 10,700 / 17,300 |
| −8.3 °C: COP min. / rated / max. | 3.39 / 3.45 / 2.44 | 4.49 / 2.99 / 2.33 |
| −15 °C: min. / rated / max.BTU/h | 1,950 / 16,600 / 16,600 | 2,300 / 15,500 / 15,500 |
| −15 °C: COP min. / rated / max. | 3.36 / 2.16 / 2.16 | 4.49 / 2.02 / 2.02 |
| Coldest point — different temperatures, not highlighted | ||
| Test temperature | −26.1 °C (−15 °F) | −20.6 °C (−5 °F) |
| Capacity min. / max. | 1,400 / 12,200 BTU/h | 2,000 / 14,000 BTU/h |
| COP min. / max. | 2.74 / 1.81 | 3.91 / 1.86 |
| Listings and refrigerant | ||
| ENERGY STAR / cold climate (NEEP) | Yes / Yes | Yes / Yes |
| AHRI certificate · NEEP listing | 214888802 · 392122 | 215434546 · 388267 |
| RefrigerantGWP per IPCC (AR4); ASHRAE 34 class | R-32 · GWP 675 · A2L | R-32 · GWP 675 · A2L |
higher marks the highest value of the same measurement, under the same conditions. It is not a recommendation. Capacities and COPs by point are not highlighted: the order changes depending on the point read.
AirGreen offers both.
A clear wall or a ceiling void: bring the shape of your open area, what is above the ceiling and your current heating, and talk it over with our team.
Where each figure comes from
Data verified on November 9, 2026. Performance: AHRI certificates and the NEEP database. Dimensions, sound, piping and features: per the manufacturer. When a source contradicts the AHRI certificate, the certificate prevails. This guide explains two types of units using two examples; it does not rank any unit. Other models have other values.
Trademarks. FUJITSU AIRSTAGE, ORION XLTH, CENTAURI and AIRSTAGE are trademarks of their respective owners. Logos are used only to identify the products shown. AirGreen is a retailer of the brand; this page is not produced, sponsored or endorsed by the manufacturer. FUJITSU AIRSTAGE systems are also sold under the GENERAL AIRSTAGE name.
Photos: AirGreen and manufacturer, for identification purposes.
Does a figure look wrong to you? Write to us: every reported figure is checked again.