Central Heat Pump ARCOAIRE H4H7T ION 2 stages | 4 Tons - 48,000 BTU (Air Handler FJMA4X) - R410A

A two-stage compressor to keep up with a large home from one season to the next

A large home does not have the same needs on a cool May morning and a heat-wave afternoon, or on a mild November night and a frigid January night. The Central Heat Pump ARCOAIRE H4H7T ION 2 stages | 4 Tons - 48,000 BTU (Air Handler FJMA4X) - R410A pairs the H4H7T48AKAAA outdoor unit, equipped with a two-stage compressor, with the FJMA4X48L0CB indoor unit, an air handler that pushes air through the existing duct system.

Like any central heat pump, it cools the whole house and handles most of the heating. Its two-stage compressor lets it adapt its output to demand instead of always starting at full output.

What "two-stage" means

A single-stage compressor has only two positions: off, or running at full output. It starts, reaches the setpoint, stops, then starts again. A two-stage compressor has a reduced stage and a full stage. When demand is moderate, the system runs on the reduced stage; when demand rises, it switches to the full stage.

The system thus switches from one stage to the other according to what the house demands. In a large home, that difference is enough to change how the system behaves for a good part of the year, with longer, steadier cycles.

Why it is useful in a 4-ton home

A 4-ton system is chosen for the most demanding days. Yet those days are the minority: most of the time, the house needs much less. A single-stage system then piles up short cycles; a two-stage system can work on its reduced stage, longer and more gently.

The result is felt mostly in steadiness: smaller swings between the moment the unit starts and the moment it stops, air that circulates more often through the ducts, and more even temperatures between the basement, the main floor and the upper floor.

One might think a smaller unit would do on ordinary days. That is true, but it would lack capacity on heat-wave days and call on the backup heat more often in winter. The two-stage compressor answers both situations with a single unit: the full size when the house needs it, a reduced stage the rest of the time.

Summer: longer cycles to remove humidity

In cooling, humidity is removed over time: the air must pass over the cold coil long enough for its water to condense and drain through the condensate drain. A unit that stops too quickly cools the air without drying it, and the house becomes cool but clammy.

On hot but not extreme days, which are common in Quebec, the reduced stage runs longer cycles that give the coil time to remove humidity. On heat-wave days, the full stage takes over to hold the setpoint all the way to the upstairs bedrooms.

Winter: reduced stage, full stage, then backup heat

In heating, the same principle applies. In mild weather, the reduced stage is often enough; when the cold sets in, the compressor switches to the full stage. This pairing is a conventional central heat pump; it is not listed as a cold-climate heat pump, and its capacity decreases as the outdoor temperature drops.

In deep cold, the air handler's backup heat, or the existing furnace in an installation that keeps it, supplements the heat. We size this backup according to the load calculation and list it in the quote.

A thermostat suited to two stages

To take advantage of the two-stage compressor, the thermostat must be able to control both stages, as well as the backup heat. An ordinary thermostat would run the system as if it had only one stage. We install a thermostat compatible with a two-stage heat pump and its backup heat, and configure it during commissioning.

A steady setpoint suits this type of system better than large swings: it lets it stay on the reduced stage as often as possible. The long run times that result are normal; they do not signal a fault, but a system doing exactly what it was chosen to do.

Homes suited to the 4-ton size

This size typically suits large homes with ducts: a two-level home with an open-concept living room and a finished basement, an enlarged split-level, or a spread-out single-storey home. These are typical examples; the size is confirmed by a room-by-room load calculation, based on insulation, windows and airtightness. A two-stage compressor does not replace proper sizing: it makes the system more flexible, but it does not correct a poorly chosen size.

System ratings

The pairing of the H4H7T48AKAAA outdoor unit and the FJMA4X48L0CB indoor unit is not listed with SEER2 ratings in the AHRI certification directory. We therefore publish no efficiency rating for this pairing. We confirm the ratings of the complete system before the quote; they also determine grant eligibility.

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 in a ducted home

The indoor unit takes the place of the old furnace or air handler and connects to the existing duct system. Before the quote, we check duct sizes and the air return, because a central heat pump only delivers its full efficiency if the airflow keeps up. The outdoor unit goes on a stand, above the snow line, on a dedicated circuit.

The duct system, on the reduced stage as on the full stage

The duct system must let through the airflow the system needs on its full stage, on the days it works hardest. Undersized ducts or an insufficient air return reduce the capacity delivered and the efficiency, and make the system noisier at the registers. We measure the duct system during the visit and list the corrections in the quote. The refrigerant is R-410A; a reversing valve lets the same system heat and cool.

The installation steps

• Visit: load calculation, inspection of the ducts, the air return and the electrical panel.
• Installation of the air handler on the plenum and return, with the planned backup heat.
• Outdoor unit on a stand, above the snow line, away from snow sliding off the roof.
• Line set insulated, evacuated and checked; condensate drain connected to a compliant discharge point.
• Electrical: dedicated circuit for the heat pump and supply for the backup heat.
• Commissioning: check on both stages, airflow, thermostat and an explanation of the settings.

Maintenance

Replace the system filter according to its format, keep the outdoor unit clear of snow and leaves, and plan annual HVAC maintenance of the coil, condensate drain and electrical connections. In winter, white vapour during defrost is normal. Because the system runs longer on its reduced stage, more air passes through the filter: check it regularly.

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 Central Heat Pump ARCOAIRE H4H7T ION 2 stages | 4 Tons - 48,000 BTU (Air Handler FJMA4X) - R410A. We assess the home room by room and confirm the right size and your grant eligibility before signing.

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