TCL Ultimate 25 Wall-Mounted Heat Pump | 18000 BTU

18,000 BTU: when a single wall-mounted unit must handle an entire floor

Moving from 12,000 to 18,000 BTU is not simply a power adjustment. It is a change in purpose. At this capacity, the TCL Ultimate 25 18,000 BTU wall-mounted heat pump no longer serves one room: it handles an entire volume, with all that this implies for air circulation.

The figure that best reflects this is not the capacity, but the 676 CFM airflow. This airflow determines whether the heat produced reaches the back of the room or remains concentrated in front of the unit. High capacity without sufficient airflow creates a hot spot, not a comfortable floor.

Cold-weather certified performance

Values from the NEEP cold-climate heat pump directory, based on AHRI-certified testing:

• 18,000 BTU/h at 8.3 °C — COP 3.80
• 18,000 BTU/h at -8 °C — COP 2.81
• 17,800 BTU/h at -15 °C — COP 1.80
• 9,860 BTU/h at -30 °C at maximum capacity — COP 1.52

The drop between the rated output and the capacity at -15 °C is 1.1%. This near absence of capacity loss is what makes it possible to rely on this unit for the primary heating of a zone rather than assigning it a simple supplemental role. And at -30 °C, the system still delivers 9,860 BTU/h, which is more than the full rated capacity of a 9,000 BTU wall-mounted unit in mild weather.

With 23.5 SEER2 and 10.0 HSPF2, seasonal efficiency remains near the top of the market despite the increased capacity—a balance many manufacturers fail to maintain as they move up in size.

Air circulation: what 676 CFM can and cannot do

An airflow of 676 CFM effectively circulates air through approximately 1,500 to 1,800 cubic feet in an unobstructed layout. In an open-concept area of 700 to 900 square feet with eight-foot ceilings, the air makes its way around. As soon as partitions, doors, or a change in ceiling height are added, the situation changes.

Here is what we systematically check before recommending this size for an entire floor:

1. The path the air must travel. A wall-mounted unit blows in a straight line. If the air must turn two corners to reach the last room, that room will not be heated.
2. Clearance height. Under a cathedral ceiling, thermal stratification sends the heat upward. The positioning and angle of the louvers must be calculated, not improvised.
3. Occupant behavior. A bedroom door closed at night interrupts circulation. If that is the intended use, it must be considered when choosing the configuration, even if that means recommending a multi-zone system.
4. Available load-bearing wall. A 43.31 in. wide unit needs a clear section of wall at the proper height, with access for drilling through to the outside.

Technical specifications

• Indoor model: H18SUH23XGE — Outdoor model: H18SUH23XGC
• AHRI certificate: 216506202 — ENERGY STAR number: 3891378
• Efficiency: 23.5 SEER2, 12.5 EER2, 10.0 HSPF2
• Refrigerant: R-454B
• Power supply: 220 V — MCA 20 A, MOP 30 A
• Piping: 1/4 in. liquid, 1/2 in. gas
• Airflow: up to 676 CFM
• Sound level: 37 to 48 dB(A) indoors, 58 dB(A) outdoors
• Indoor dimensions: 43.31 x 8.75 x 13.13 in. — outdoor: 36.50 x 15.00 x 27.50 in.
• ENERGY STAR cold-climate certification: yes

Two figures change compared with the smaller sizes and deserve to be anticipated. The gas-side piping increases to 1/2 in., which makes bending less flexible and requires planning the route before drilling. And the MCA rises to 20 A, with 30 A protection: in an older building with an already loaded electrical panel, this is the first point to validate, even before discussing the unit’s location.

$2,160 in financial assistance, and the verification that must come first

This model is eligible for Hydro-Québec’s LogisVert program, with assistance of $2,160 for an existing-home owner. In new construction, the amount reaches $2,520; for a multiplex, an optimization option raises the assistance to $3,150.

The assistance applies to a specific unit identified by its AHRI certificate number and its indoor-outdoor combination. Replacing the indoor unit with an equivalent model from another series breaks the certified combination and may make the application ineligible. This is another reason to have the configuration validated before ordering rather than after installation.

The outdoor unit: what people forget to plan

At this size, the outdoor unit measures 36.50 x 15.00 x 27.50 in. It is no longer a small, discreet box, and its placement becomes a genuine consideration, particularly in dense areas.

We systematically raise it above the typical snow depth for the area—which, on the North Shore, means higher than in central Montreal. Condensate produced during defrost cycles must be able to drain without forming an ice base beneath the unit, and the rear air intake must remain clear throughout the winter. A properly installed unit that is buried under a snowbank in February loses efficiency exactly when it is needed most.

The 58 dB(A) measured outdoors also requires consideration of the surrounding area. In a narrow backyard in the Plateau, Verdun, or an area with adjoining duplexes, the location must be chosen with the neighbour’s windows in mind, while anti-vibration mounts help prevent the building structure from transmitting noise.

Maintenance and service life

The indoor filters of a unit this size load up faster than those of a smaller wall-mounted unit, simply because they process more air. Monthly cleaning during periods of heavy use is realistic. We recommend professional cleaning of the coil and condensate pan every two years, along with a refrigerant charge check during the same visit.

The self-cleaning function dries the coil after a cooling cycle, which limits mould growth in the pan. This is useful, but it does not replace a deep cleaning.

Why AirGreen

The 18,000 BTU size is where a poor assessment costs the most, because it is often purchased to replace an existing heating system. If the capacity is incorrectly assessed or the airflow is poorly planned, the customer ends up with a high-performance unit that heats only part of the floor, while supplemental heating runs more than expected.

We perform the analysis beforehand, and we say no when the home’s layout is not suited to a single wall-mounted unit. That is more useful than making a sale.

Contact AirGreen for an on-site assessment and a complete quote for the TCL Ultimate 25 18,000 BTU, in Montreal, Laval, Longueuil, on the North Shore, and on the South Shore.