Central Heat Pump ARCOAIRE R4H5S Economy | 3.5 Tons - 42,000 BTU (Air Handler FJMA4X) - R410A

Replace the electric furnace without touching the home's ducts

Many homes heated by an electric furnace already have what a central heat pump needs: a duct system that serves every room. The Central Heat Pump ARCOAIRE R4H5S Economy | 3.5 Tons - 42,000 BTU (Air Handler FJMA4X) - R410A pairs the R4H5S42AKAAA outdoor unit with the FJMA4X42L0BB indoor unit, an air handler that takes the place of the furnace and pushes air through the existing duct system. The home stays electrically heated, but by a system that moves heat instead of producing it, heating in winter and cooling in summer.

The 3.5-ton size sits between the common 3-ton and 4-ton sizes, which makes it possible to closely follow the load calculation of medium to large homes.

An electric-furnace home that already has its ducts

A forced-air electric furnace distributes heat through ducts and registers in each room, with a central air return. That is exactly the duct system a central heat pump needs. Instead of installing wall units room by room, you replace the unit at the heart of the system and keep the existing registers.

The duct system does need to be checked. A heat pump blows air that is less hot than an electric furnace, but in greater volume and for longer. The ducts, and especially the air returns, must let that airflow through. We measure and inspect the duct system before the quote and list the adjustments needed rather than finding them on installation day.

What changes in the mechanical room

The FJMA4X42L0BB air handler usually goes where the old electric furnace stood and connects to the existing supply plenum and return. It houses the indoor coil, the blower and the filter, and it receives the electric backup heat, which takes over the role of the old furnace's elements.

If the home also has an aging central air conditioner, its coil and outdoor unit are removed at the same time, and its refrigerant is recovered before dismantling. The thermostat is replaced with a model that manages the heat pump and its backup, and the mechanical room keeps one unit instead of two.

Electrical capacity, the first thing to check

Replacing an electric furnace with a central heat pump redistributes the load on the panel: the heat pump on one side, the air handler's backup elements on the other. In an older home, the panel is often already well filled, and the old furnace's circuit does not always suit the new unit as is. It is the first point we check during the visit.

We assess the available capacity, the space for breakers and the cable route to the outdoor unit and to the air handler. The heat pump is fed by a dedicated circuit. If the panel or the service needs to be modified, we state it clearly in the written quote.

Homes suited to the 3.5-ton size

This size typically suits a two-level cottage or house from the fifties or sixties with a basement, an enlarged bungalow or a good-sized semi-detached home. Many are heated by a forced-air electric furnace, and their insulation varies a great deal depending on the renovations done since they were built.

That is why the size is confirmed by a room-by-room load calculation. A recently insulated attic, new windows or a finished basement change the result. If the calculation shows that a 3-ton or 4-ton size is a better fit, we recommend it.

How the heat pump heats the house

An electric furnace produces heat with heating elements: it gives back as heat the electricity it uses, and no more. A heat pump moves it instead: the refrigerant captures the heat contained in the outdoor air, the compressor concentrates it, then the indoor unit's coil releases it into the air circulating through the ducts. The system runs on R-410A.

The heat therefore arrives gentler and steadier than with an electric furnace's elements. Instead of short bursts of very hot air, air circulates longer at a moderate temperature. Most people find the house more even, with smaller gaps between the basement and the bedrooms. The blower can also run continuously, depending on the thermostat setting, to mix the air between levels and pass it through the filter.

In deep cold, electric backup heat

This pairing is a conventional central heat pump; it is not listed as a cold-climate heat pump. Its heating capacity drops with the outdoor temperature. When the cold becomes too intense, the air handler's backup elements take over and keep the house heated.

The thermostat manages this handoff: the heat pump first, the backup second, and only when needed. We size the backup according to the load calculation and the available electrical capacity.

A useful clarification: the air handler's backup works like the elements of your current electric furnace. In deep cold, it therefore plays the role the furnace plays today; the rest of the winter, the heat pump does most of the work and the elements stay at rest.

Summer: cooling through the same ducts

Many homes heated by an electric furnace have never had central air conditioning, or make do with an old air conditioner at the end of its life. With this system, cool air travels in summer through the same ducts as the heat in winter. The indoor coil also removes moisture, which drains through the condensate drain; this is often the most appreciated difference in a finished basement.

Duct systems designed for heating sometimes have few registers upstairs, where summer heat builds up. We check this during the visit and suggest simple corrections to the duct system if needed. After that, a reasonable summer setpoint and a clean filter are usually enough to keep the whole house comfortable.

System ratings

The pairing of the R4H5S42AKAAA 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 electric furnace 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 steps of the job

• Assessment: load calculation, duct inspection, electrical panel check and choice of the outdoor location.
• Unit replacement: removal of the electric furnace and installation of the air handler on the plenum and return.
• Outdoor unit: stand above the snow line, away from snow sliding off the roof.
• Line set and drain: line set insulated, evacuated and checked; condensate drain connected to a discharge point.
• Electrical and commissioning: dedicated circuit, backup heat, compatible thermostat, check of the charge and airflow.

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. The same visit checks the backup elements, which have taken over from those of the old furnace.

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 R4H5S Economy | 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.

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