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Wall-mounted or ducted heat pump: what changes in your home
A wall-mounted unit blows air from the wall of the room it is installed in. A ducted unit hides above a ceiling, in an attic or in the basement, and pushes air through short ducts to grilles. To make the difference concrete, this guide follows two 12,000 BTU FUJITSU AIRSTAGE units, each with its own AHRI certificate.
ORION XLTH · 12,000 BTU
ASUH12KZAS / AOUH12KZAH1 · AHRI 214888802
View the product page
Manufacturer imageARUH12KUAS · 12,000 BTU
ARUH12KUAS / AOUH12KUBS1 · AHRI 217734522
Ask for detailsWhat 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 its own certificate: the difference comes from these two combinations, not only from one being wall-mounted and the other ducted. 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.
Remove the ceiling: here is where each one sits
The same room, seen from the front. The wall-mounted unit is on the wall, in plain view. The ducted unit is in the space between the ceiling and the structure above, with its ducts. Move the slider to remove the ceiling and see what it hides. Both units are drawn to the same scale, from their published dimensions.
ORION XLTH wall-mounted unit: what you see
ARUH12KUAS ducted unit: what you see
Nine differences, one after another
Both units heat and cool. What sets them apart is the path the air takes, the space they need and what it takes to install and maintain them.
Every elbow and every grille slows the air
A ducted unit has to push air through ducts. The longer, narrower or more bent they are, the more they resist: this is external static pressure. FUJITSU AIRSTAGE publishes the range its fan accepts. The wall-mounted unit has no duct: it blows directly into the room.
The range accepted by the example ducted unit
From 30 to 200 Pa, or 0.12 to 0.80 in. of water column, according to submittal 12KUBS1R. The unit detects static pressure automatically to adjust the airflow. Your duct calculation, however, is done on site: length, elbows, grilles and filter.
Published airflow, by speed
Manufacturer values for the ducted unit, identical in heating and cooling. The wall-mounted unit’s airflow is not shown here: it blows directly into the room, with no duct to supply.
Below −15 °C: every published figure, at its exact temperature
NEEP measures both examples at −15 °C. Lower down, the ducted unit 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 ducted unit’s brochure does not publish an equivalent percentage.
What FUJITSU AIRSTAGE states about each one
One row per group of features, based on the wall-mounted unit’s brochure and the ducted unit’s submittal. When a document says nothing, the card says so.
Wall-mounted: wireless remote included; built-in Wi-Fi, AIRSTAGE Mobile app.
Ducted: optional infrared receiver and remote (UTY-LBTUM); optional Wi-Fi; wired wall controls available.
Wall-mounted: Economy, Energy Saving, Powerful, Minimum Heat, Occupancy.
Ducted: Economy, Energy Saving, Powerful, Minimum Heat; weekly and 24-hour timer, sleep mode.
Wall-mounted: not indicated in the brochure; the drain follows the piping.
Ducted: built-in drain pump, according to the submittal.
Wall-mounted: not applicable, no duct.
Ducted: automatic static pressure detection; 0.12 to 0.80 in. w.c. (30 to 200 Pa).
Wall-mounted: not indicated in the documents consulted.
Ducted: leak sensor built into the indoor unit.
Wall-mounted: one set point for the room it blows into.
Ducted: one set point for all connected rooms; compatible with Airzone zoning, BACnet and Modbus, according to the submittal.
How loud each one is, according to FUJITSU AIRSTAGE
The manufacturer measures both indoor units in an anechoic chamber, at each speed. For the ducted unit, this is the sound of the unit itself: in the room, what you mostly hear is the air at the grilles, since the unit is behind the ceiling.
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 wall-mounted unit is measured where it blows; the ducted unit, at the unit, which will be hidden. In a real house, the ducted unit’s sound also depends on the ducts and grilles.
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.
Two indoor units at the same scale
The two example outdoor units have the same published dimensions. Everything else changes: the shape of the indoor unit, its weight, the allowed piping.
Front views, same scale
Width to scale: 1,000 mm = the full width of the photo area. The photo of the ducted unit also shows its side connections; the published width is 700 mm.
| Installation | ORION XLTH wall-mounted unit | ARUH12KUAS ducted unit |
|---|---|---|
| Indoor unit W × H × D, weight | 38 9/16 × 11 × 9 7/16 in, 28 lb | 27 9/16 × 11 13/16 × 27 9/16 in, 66 lb |
| External static pressure | Not applicable: no duct | 0.12 to 0.80 in. w.c. (30 to 200 Pa) |
| Maximum piping length | 82 ft | 98 ft |
| Precharged length | 49 ft | 65 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 | 0.7 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 12KUBS1R (version 20260707A) for the ducted unit. The submittal publishes dimensions as height × width × depth: 300 × 700 × 700 mm for the indoor unit, 632 × 799 × 290 mm for the outdoor unit.
Your list for the visit
Check the questions you want to ask. They cover what really decides between a wall-mounted and a ducted unit in your home.
What people ask us about wall-mounted and ducted units
Is a ducted unit the same thing as a central heat pump?
Both blow air through ducts. In this guide, the ducted unit is a compact unit connected to short ducts, for a few neighbouring rooms; a central system connects to the duct network of the whole house. Natural Resources Canada describes a ducted installation as one where the indoor coil is located in a duct.
How much space is needed above the ceiling?
The example indoor unit is 300 mm high, 700 mm wide and 700 mm deep, and weighs 30 kg (66 lb), according to the submittal. You also need room for the ducts, connections and drain, plus service access; the installation manual specifies the clearances.
Why don’t the two examples have the same outdoor unit?
Because FUJITSU AIRSTAGE does not certify a wall-mounted unit with the ducted unit’s outdoor unit (AOUH12KUBS1), according to the NEEP database consulted. Each example therefore has its own AHRI certificate. The differences in efficiency and cold-weather performance on this page come from these two combinations, not only from the type of indoor unit.
Can each room be controlled separately with a ducted unit?
With a single ducted unit, the connected rooms share one set point. The submittal indicates compatibility with the Airzone zoning system; each wall-mounted unit, on the other hand, has its own set point.
Is the ducted unit quieter in the bedroom?
The unit is behind the ceiling; in the room, what you mostly hear is the air at the grilles. FUJITSU AIRSTAGE publishes 24 to 35 dB(A) for the unit and 23 to 43 dB(A) for the wall-mounted unit, in cooling, in an anechoic chamber. The actual result depends on the ducts and grilles.
Which one heats better in extreme cold?
For these two examples, the wall-mounted unit is certified down to −26.1 °C and the ducted unit down to −20.6 °C, each at the bottom of its stated range. These are two different combinations: the same ducted unit exists with an XLTH outdoor unit, under another certificate.
All AHRI and NEEP values for both examples
| Certified value | ORION XLTH wall-mounted unit | ARUH12KUAS ducted unit |
|---|---|---|
| Cooling | ||
| Rated capacity at 35 °C | 12,000 BTU/h | 12,000 BTU/h |
| SEER2 | 30.5 | 19.1 |
| EER2 | 16 | 12.7 |
| Heating, same conditions | ||
| HSPF2 region IV / V | 12.7 / 10.1 | 10.5 / 8.9 |
| 8.3 °C: min. / rated / max.BTU/h | 3,500 / 16,000 / 23,600 | 3,400 / 16,000 / 19,400 |
| 8.3 °C: COP min. / rated / max. | 5.13 / 4.64 / 3.07 | 5.54 / 3.75 / 3.09 |
| −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 / 2.93 / 2.39 |
| −15 °C: min. / rated / max.BTU/h | 1,950 / 16,600 / 16,600 | 2,100 / 15,500 / 15,500 |
| −15 °C: COP min. / rated / max. | 3.36 / 2.16 / 2.16 | 4.10 / 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 / 1.87 |
| Listings and refrigerant | ||
| ENERGY STAR / cold climate (NEEP) | Yes / Yes | Yes / Yes |
| AHRI certificate · NEEP listing | 214888802 · 392122 | 217734522 · 306759 |
| 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.
Wall-mounted or ducted, the answer is often in your ceilings. Talk it over with our team: bring the number of rooms involved, what is above the ceiling and your current heating.
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 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.