Wall-Mounted Heat Pump ARCOAIRE 16.8 SEER | 12,000 BTU - R454B

A cool living room all summer, and baseboards that heat less the rest of the year

For many owners, the starting point is simple: get rid of the window air conditioner, get the view back and sleep cool during heat waves. If the same wall head can also heat the living room in spring and fall, those are hours when the baseboards stay off. The Wall-Mounted Heat Pump ARCOAIRE 16.8 SEER | 12,000 BTU - R454B meets that need, with an honest approach to what it does in the dead of winter.

Its certified ratings are 18.0 SEER2, 8.8 EER2 and 8.8 HSPF2. It runs on R-454B refrigerant and its variable-speed compressor adjusts its output continuously. The series name mentions 16.8 SEER; to compare units, we rely on the SEER2 ratings on the certificate.

A unit designed for summer first

In cooling mode, the nominal capacity is 12,000 BTU/h, which typically suits a spacious living room, an open living-kitchen area or a small, well-insulated home. Unlike a window air conditioner, the compressor stays outside, the window closes normally and the wall head spreads cool air up high, across the whole room.

The SEER2 rating of 18.0 describes average efficiency over the whole cooling season; the EER2 rating of 8.8 describes efficiency at the hottest moment. Because the compressor slows down as soon as the room approaches the set point, the unit spends most of the summer at low speed, where it uses the least.

July humidity

In the Montreal area, the humidity of summer days weighs as much as the heat. A properly sized variable-speed heat pump runs long at low speed: the indoor coil stays cold, water vapour in the air condenses on it and drains away. This continuous dehumidification makes the living room comfortable at a reasonable set point, without muggy air or a damp chill.

That is also why we advise against choosing bigger than necessary. An oversized unit cools very quickly, stops, then starts again: the air is cold but stays loaded with moisture.

Spring and fall without turning on the baseboards

Between the end of the cooling season and the first real cold, there are long weeks of cool nights and mild days. That is when a heat pump is most efficient in heating: the temperature difference between outside and inside is small, and the compressor works effortlessly. Rather than turning on the baseboards in September, the wall head heats the living room throughout this period.

The same reasoning applies to cool May mornings or rainy October evenings: a steady set point on the heat pump is enough, and the house no longer swings from chilly to the dry heat of baseboards. Over a full year, these transition weeks account for a large share of heating hours, and that is when the heat pump works at its best efficiency.

Winter: what the certificate publishes

The certificate lists 8,000 BTU/h at -8 °C (17 °F), about 67% of nominal capacity, with a COP of 2.58, and 7,000 BTU/h at -15 °C (5 °F), about 58%, with a COP of 2.21. The two points are measured separately; we report each one as published.

These figures are clear: at these temperatures, the heat pump still heats with very good efficiency, but its capacity no longer covers the full demand of a living room in the middle of January. The baseboards therefore stay in place. The recommended setting is simple: the heat pump holds the main set point, and the baseboard thermostats are set a few degrees lower. They switch on by themselves when the heat pump needs help, and stay off the rest of the time.

Which rooms it suits

A living room, a large bedroom or a well-insulated small apartment: that is this size's territory. The head installed in the main room also cools the neighbouring rooms whose doors stay open. A closed bedroom, on the other hand, does not benefit from the living room's cool air; if you want to cool it, a dedicated head or a multi-zone configuration will be better suited. We tell you during the visit.

Inverter and R-454B refrigerant

A wall-mounted heat pump moves heat instead of producing it. In summer, it captures the living room's heat and rejects it outside; in winter, it does the reverse. Inverter technology varies the compressor's speed instead of running all-or-nothing, which stabilizes the temperature and limits starts.

R-454B is the new-generation refrigerant, with a much lower global warming potential than the previous generation. It is classified A2L and calls for precise installation methods, which we apply on every job.

The ratings, plainly

• SEER2 of 18.0: cooling efficiency over the whole season.
• EER2 of 8.8: cooling efficiency at the hottest point.
• HSPF2 of 8.8: heating efficiency over a full season.
• COP of 2.58 at -8 °C and 2.21 at -15 °C: the heat delivered for each unit of electricity, while an electric baseboard delivers one for one.

These figures come from certificate AHRI 215324156, published by NEEP.

LogisVert

This pairing does not carry an amount on Hydro-Québec's LogisVert list of October 19, 2026. If the grant matters for your project, we will point you to an eligible pairing of comparable size.

Installation, step by step

Visit and location

The visit is free. We measure the room, look at the windows and orientation, then run a load calculation. The wall head is secured to the framing, up high, on a wall that lets cool air cover the living room and reach the open rooms, with a drainage slope for condensate. The outdoor unit goes on a ground or wall stand, above the snow line, away from bedroom windows, including the neighbours'.

For a west-facing or heavily glazed living room, we factor it into the calculation: it is often the afternoon sun's heat that determines the cooling capacity needed, far more than the room's floor area.

Lines, electrical and commissioning

The refrigerant lines, the communication cable and the drain go through a single opening, sealed on both sides, and a line cover can finish the run. The system needs a dedicated circuit: we check the panel capacity during the visit. At commissioning, the circuit is evacuated and checked for tightness, then we test cooling, heating and drain flow, and set the baseboards to work as backup.

Maintenance

A unit that does a lot of cooling collects dust and moisture in the indoor coil. Before summer, also check that drain water flows freely outside: a blocked drain can make the wall head drip. Rinse the indoor filters every two weeks in season, keep the outdoor unit clear of snow and leaves, and plan annual HVAC maintenance of the coils, drain and electrical connections. In winter, white vapour during defrost and a short pause in heating are normal. Our cleaning service takes over when you prefer to hand off the annual visit.

AirGreen, for the life of the installation

A family business active for more than fifteen years in Montreal, Laval, Longueuil, the North Shore and the South Shore, we hold RBQ licences for ventilation, refrigeration and electrical work and carry $5,000,000 in liability insurance. The in-home assessment is free, the quote is in writing, and our financing options let you choose the right unit rather than the cheapest one.

Request your free estimate for the Wall-Mounted Heat Pump ARCOAIRE 16.8 SEER | 12,000 BTU - R454B. We assess your living room, confirm the right size and explain how the heat pump and your baseboards will share the winter.