Central Heat Pump ARCOAIRE HSH6 Premium | 3.5 Tons - 42,000 BTU (Air Handler FJMA4X) - R410A

Your central air conditioner is reaching the end of its life: replace it with a system that also heats

In a home with ductwork, replacing an old central air conditioner is the right time to switch to a central heat pump. From the outside, the unit looks like an air conditioner; the difference is that it also works in winter and handles most of the heating. The Central Heat Pump ARCOAIRE HSH6 Premium | 3.5 Tons - 42,000 BTU (Air Handler FJMA4X) - R410A pairs the HSH642GKA outdoor unit with the FJMA4X42L0BB indoor unit, an air handler that pushes air through the existing duct system.

This pairing from Arcoaire's Premium range, in the 3.5-ton size, is offered while supplies last.

From central air conditioner to central heat pump

A central air conditioner captures heat from the house and releases it outdoors, from June to September. A heat pump does the same in summer, but it has a reversing valve that flips the cycle in winter: it then captures the heat contained in the outdoor air and delivers it indoors through the ducts. The refrigerant is R-410A.

This change of use has concrete consequences. The outdoor unit now runs twelve months a year, under snow and freezing rain, and it must be installed accordingly. The indoor system must also be able to heat, with backup for deep cold. The following sections explain what this changes in your home.

The outdoor location often has to change

A central air conditioner is often set on a slab at ground level, sometimes under an eave or near a walkway. That did not matter for a unit that sleeps all winter. A heat pump, however, must stay clear of snow to breathe, and it produces meltwater during its defrost cycles.

We therefore install the HSH642GKA outdoor unit on a stand, above the snow line, away from snow and ice falling off the roof. We avoid placing it above a walkway or stairs, where defrost water could freeze. The old air conditioner's location is sometimes usable, but not always.

The line set: reuse or replace

The copper line set between the outdoor unit and the indoor unit is a key part of the system. With an old air conditioner, it may have been sized for another unit, used with another refrigerant or have insulation damaged by the sun. We inspect it and decide, case by case, whether it needs to be replaced.

In every case, the line set is insulated along its full length, evacuated and checked before the refrigerant is released. It is a step you no longer see once the job is done, but it matters for the life of the compressor.

A matched air handler

In many original installations, the air conditioner's coil sits on top of the furnace, and the two units were bought at different times. Here, the FJMA4X42L0BB indoor unit combines the coil, the blower and the filter in a single unit, chosen to work with the outdoor unit. It takes the place of the old furnace or air handler and receives the backup heat.

This factory pairing avoids improvised combinations and simplifies maintenance: one indoor unit to inspect, one filter to replace.

Why the size may differ from the old air conditioner

In Quebec, a home's heating needs generally exceed its cooling needs. The size of a central heat pump is therefore not copied from the old air conditioner: it is calculated room by room, taking into account the insulation, windows and airtightness of the house.

The 3.5-ton size typically suits a two-level semi-detached home with a finished basement, a split-level home or a mid-sized cottage. The load calculation confirms the size; if another one fits better, we recommend it.

Winter and backup heat

This pairing is a conventional central heat pump; it is not listed as a cold-climate heat pump. Its heating capacity decreases as the outdoor temperature drops. In deep cold, the air handler's backup heat, or the furnace kept in some installations, takes over.

The thermostat runs the heat pump first and only calls on the backup when necessary. We size this backup according to the load calculation and list it in the quote.

A heat pump thermostat

The thermostat for an air conditioner and a furnace cannot manage a heat pump. We install a compatible thermostat that controls the outdoor unit in heating and cooling, then the backup heat when the heat pump is no longer enough. Most of these thermostats also offer an emergency heat mode, which uses only the backup.

This emergency mode is only for when the outdoor unit is out of service, while you wait for our visit. Left on by mistake, it deprives the house of the heat pump's benefits. We show these settings during commissioning, so everyone in the home knows how to use them.

Summer, as before, but better distributed

In summer, the system cools the whole house through the ducts and removes moisture from the air; condensed water drains through the condensate drain. If the upper floor stayed hot with the old air conditioner, the cause is often in the duct system: insufficient air returns, poorly balanced registers, an overly restrictive filter. We check these points before concluding that a bigger unit is needed.

System ratings

The pairing of the HSH642GKA outdoor unit and the FJMA4X42L0BB 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.

• Assessment: load calculation, inspection of the ducts, the air return and the existing line set, choice of the outdoor location.
• Removal of the old air conditioner and indoor unit, with refrigerant recovery according to the rules.
• Electrical: the old air conditioner's circuit is not always suitable; we check the panel, the heat pump circuit and the backup heat circuit.
• Condensate drain connected to a compliant discharge point, with its slope checked.
• Commissioning in heating mode, and in cooling mode when the season allows, then thermostat setup.

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. Never put a winter cover on the outdoor unit the way people did with an air conditioner: the heat pump needs it uncovered to heat.

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 HSH6 Premium | 3.5 Tons - 42,000 BTU (Air Handler FJMA4X) - R410A. We assess the home room by room and confirm the right size and your grant eligibility before signing.

Offered while supplies last.

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