2-Zone Heat Pump ARCOAIRE D5CMHA | 18,000 BTU - R454B

Two rooms, sized right, on a single condenser

A bedroom that overheats in July, an office that stays cold in January: two rooms with different needs call for two separate set points. The 2-Zone Heat Pump ARCOAIRE D5CMHA | 18,000 BTU - R454B is designed for exactly that case. Its 1.5-ton D5CMHAH18CAK condenser serves 2 zones, which is also its maximum: the system is meant for two rooms, no more, no less. Each zone gets a D5FSHAH09XAK wall-mounted heat pump head with its own remote, and the variable-speed compressor adjusts its capacity depending on whether one head or both are calling for heat or cooling.

Its ratings are 25.0 SEER2, 15.0 EER2 and 10.5 HSPF2. The system is ENERGY STAR certified with the cold-climate designation under ENERGY STAR ID 3620802. The certificate still lists its capacity at -30 °C, and the system qualifies for a $2,400 LogisVert grant.

The homes that get the most out of this size

This size is aimed at smaller homes where two rooms carry most of the comfort. The most common case is a 4 ½ condo: one head in the open living-kitchen area, the other in the primary bedroom. It also goes upstairs in a two-storey house, when two bedrooms under the roof become stifling in summer while the ground floor is already air-conditioned, or in a bungalow for a bedroom and a home office at opposite ends of the hallway.

The size is confirmed during the visit, though, not on a floor plan. A corner room with two exterior walls, large west-facing windows, a poorly insulated attic or a floor above a garage all change the real load. A recent, well-insulated home handles larger rooms; an older house with tired windows needs more margin. That is why we run the calculation room by room before recommending this model rather than a larger one.

Two zones at most: a choice to make with eyes open

The D5CMHAH18CAK condenser does not accept a third head. If you plan to finish the basement or add a bedroom in a few years, a condenser that accepts more zones is worth comparing now, because you cannot graft an extra head onto a system already at its maximum. Conversely, when the plan is clear and two rooms are enough, this size avoids paying for reserve capacity that will never be used and keeps the compressor in the range where it works most efficiently.

Since both heads are the same model, maintenance is identical from one room to the other: same filter to rinse, same front panel to open, same remote to learn.

Two heads, one operating mode

In a multi-zone system like this one, both heads work in the same mode at any given time: heating or cooling. Each room keeps its own temperature set point and its own fan speed, but one head cannot heat while the other cools. In practice, this comes up mostly in spring and fall, when a bedroom facing the afternoon sun would like some cooling while the north-facing office still wants a little heat. The simplest approach is then to choose the mode of the season and adjust each room's set point, or to leave one head on fan only.

The right size means drier air in summer

An oversized unit cools the room in a few minutes, stops, then starts again: the air reaches the set point, but the humidity stays. A properly sized system runs longer at low speed, and it is during these long cycles that the indoor coil condenses water out of the air and sends it down the drain. In a bedroom, the difference is felt at bedtime: the room is cool without being clammy. The dehumidification mode on the remote strengthens this effect on humid days when the outdoor temperature stays moderate.

The 15.0 EER2 rating measures cooling efficiency at a fixed hot condition: it is the figure that speaks to heat-wave afternoons, when both heads are working at the same time.

The inverter compressor and R-454B refrigerant

A fixed-speed compressor runs flat out or stops. The D5CMHA's inverter compressor varies its speed continuously: it starts gently, slows down as it approaches the set point, then holds the temperature with small swings. In a multi-zone system, this modulation counts twice, since demand changes depending on whether one room or both are calling; the condenser then meters the refrigerant sent to each head.

The system uses R-454B, a new-generation refrigerant that replaces, in residential heat pumps, fluids with a much higher global warming potential. Classified as mildly flammable, it requires precise handling methods and suitable tools: the quality of the installation matters as much as the choice of equipment.

Winter in Montreal: what the certificate shows

A heat pump loses capacity as the cold sets in; what matters is how much it keeps, and at what efficiency. This system's certificate lists 20,000 BTU/h at -8 °C (17 °F) and 19,000 BTU/h at -15 °C (5 °F). The two points are measured separately; we report each one as published.

• COP of 2.53 at the -8 °C point
• COP of 2.00 at the -15 °C point
• Maximum capacity at -30 °C: 10,000 BTU/h, COP of 1.30
• Heating certified down to -30 °C

For two modestly sized rooms, these figures mean the system keeps heating through the usual January cold, with an efficiency that stays above that of an electric baseboard. During extreme cold snaps, the published capacity drops: we recommend keeping the existing baseboards as backup, especially in a corner room. These figures come from certificate AHRI 215357125, published by NEEP.

SEER2, HSPF2 and COP, translated for the bill

SEER2 measures seasonal cooling efficiency: the higher it is, the less each hour of cooling costs in electricity, which matters in a home where the bedrooms are cooled every summer night. HSPF2 does the same job for the heating season; at 10.5 HSPF2, the system draws considerably more heat from each kilowatt-hour than a resistance appliance. Finally, COP is the ratio between the heat delivered and the electricity consumed at a specific temperature: a COP of 2.00 means two units of heat for one unit of electricity, whereas an electric baseboard returns only one.

The $2,400 LogisVert grant

The system is listed in Hydro-Québec's LogisVert program, with $2,400 for the owner of an existing home, according to the list in effect on the installation date. We confirm eligibility before signing and prepare the detailed invoice, model numbers and proof of payment. Our page on the efficient heat pump grant summarizes the program's conditions.

From the visit to the annual maintenance

Installation by AirGreen, step by step

Everything starts with an in-home assessment. We measure both rooms, note the orientation, windows and insulation, then run the load calculation for each zone. In a condominium, we also check the syndicate's rules on the condenser location and the routing of lines on the facade before fastening anything.

• The condenser goes on a wall bracket or a stand, above the snow line and away from snow sliding off the roof.
• Each head gets its own refrigerant line set, communication cable and drain, grouped under a finishing cover on the outside.
• The drain flows by gravity; when the route does not allow it, a condensate pump takes over.
• The condenser is connected to a dedicated circuit, after checking the capacity of the electrical panel.
• Commissioning includes the leak test, the vacuum, a check of each zone and programming the remotes with you.

Maintenance: a few habits, one visit a year

Rinse the filters of both heads every two weeks in season and let them dry before putting them back. Keep the condenser clear of snow, ice and leaves, and do not cover it in winter. Once a year, a complete HVAC maintenance visit cleans the coils and blower wheels, checks the drain and tightens the 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 2-Zone Heat Pump ARCOAIRE D5CMHA | 18,000 BTU - R454B. We assess your two rooms, confirm that this size suits them and check your grant eligibility before signing.

Warranty: 10 years on the compressor, 10 years on parts and 6 years on labor.