Central Heat Pump ARCOAIRE N4H5S Performance | 1.5 Tons - 18,000 BTU (Air Handler FJMA4X) - R410A
Replace an aging central air conditioner with a system that also heats
In many homes in the region, cooling already runs through the ducts: a central air conditioner installed years ago, connected to an electric furnace. When that air conditioner reaches the end of its life, it is the right time to replace it with a central heat pump, which cools the same way in summer but also heats the house through much of the winter. The Central Heat Pump ARCOAIRE N4H5S Performance | 1.5 Tons - 18,000 BTU (Air Handler FJMA4X) - R410A pairs the N4H5S18AKAAA outdoor unit with the FJMA4X18L0AB cabinet, which pushes air through the existing duct system.
The pairing is certified at 14.3 SEER2, 12.0 EER2 and 7.5 HSPF2. The 1.5-ton size is aimed at compact homes: a townhouse, a condo with its own duct system, a small well-insulated bungalow.
When the central air conditioner reaches the end of its life
A central air conditioner does only one thing: remove heat from the house in summer. The rest of the year, the electric furnace does the heating, with resistance elements that turn each kilowatt-hour into the same amount of heat, no more. A central heat pump takes over the air conditioner's outdoor spot and the duct system, but it also works the other way: in winter, it captures heat from the outdoor air and brings it into the house.
The replacement is therefore done without touching the air distribution. The grilles stay where they are, the thermostat stays on the same wall, and the old furnace gives way to the heat pump's cabinet. We use the visit to check what the old system was sometimes hiding: a disconnected duct in the attic, a return that is too small, a condensate drain that does not flow well.
A 1.5-ton size for a compact home
The size is chosen from the home's heating and cooling needs, not from the label on the old unit. Many central air conditioners were installed one size too big; replacing them like for like repeats the mistake. The 1.5-ton size suits townhouses, condos with their own air handler, the upper floor of a duplex served by its own duct system, or a small well-insulated single-storey house.
Our room-by-room load calculation takes into account insulation, windows, orientation and rooms under the roof. If the house is more demanding than it looks, for example an older single-storey house with poorly insulated walls, we say so during the visit and propose the next size up.
The role of the FJMA4X cabinet
The FJMA4X18L0AB cabinet is the system's air handler. It contains the indoor coil and the blower that pushes air through the ducts, and it takes the place of the old electric furnace, in the basement or a utility closet. It can house backup electric heating elements, which we size according to the house and the capacity of the electrical panel.
These elements are the system's safety net. The heat pump heats first; the backup only comes on when it is no longer enough, in deep cold, or briefly during a defrost to avoid blowing cool air into the rooms.
The pairing's ratings, in plain words
SEER2 measures cooling efficiency over a whole season; at 14.3, it places this pairing among conventional systems. EER2, at 12.0, measures efficiency on a hot day, when cooling runs at full demand. HSPF2, at 7.5, measures heating efficiency over a season: it is the most telling rating in Quebec, where heating weighs heavily on the electricity bill.
Finally, COP compares the heat delivered with the electricity used at a specific temperature. An electric furnace or a baseboard has a COP of 1. The certificate lists a COP of 1.88 at -15 °C: even at that temperature, the heat pump delivers almost twice the energy it uses.
Heating when the cold sets in
The certificate lists 10,100 BTU/h at -8 °C and 7,700 BTU/h at -15 °C. The two points are measured separately; we report each one as published. Compared with the nominal size of 18,000 BTU, the heat pump provides about 56% of its capacity at -8 °C and 43% at -15 °C.
In practice, the heat pump heats the house on its own on mild fall and spring days and during the less cold spells of winter. When the cold becomes more intense, the cabinet's backup elements add to the heat it supplies. The backup is added to the heat pump; it does not take its place.
These figures come from certificate AHRI 210998759, as published in the AHRI certification directory.
Ducts: what we check before the quote
A central air conditioner and a heat pump use the same ducts, but the heat pump moves air through them all year. Before quoting a price, we examine:
- the size of the main ducts and branches, so the airflow keeps up;
- the return air, often too small in townhouses, especially upstairs;
- the sealing and insulation of ducts that run through an attic or crawl space;
- the location and format of the filter;
- the condition of the plenum and connections where the new cabinet ties in.
A central heat pump only delivers its full efficiency if the airflow keeps up. When a correction is needed, we list it in the written quote.
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.
A managed replacement, from the visit to commissioning
How the work proceeds
- Free visit: load calculation, inspection of the ducts and the electrical panel, choice of the outdoor location.
- Removal of the old equipment: recovery of the air conditioner's refrigerant, removal of the outdoor unit and the old furnace.
- Installation of the FJMA4X cabinet: connection to the plenum and return air, condensate drain to a floor drain or a pump.
- Outdoor unit: on a stand or a wall bracket, above the snow line, out of the roof drip line.
- Refrigerant line: insulated copper, brazing, pressure test and vacuum before the valves are opened.
- Electrical: dedicated circuit, outdoor disconnect, power to the backup elements and a thermostat designed for a heat pump.
- Commissioning: refrigerant charge, airflow, defrost, settings, then an explanation of how everything works.
The thermostat and the first few weeks
A heat pump heats differently from an electric furnace. The air coming out of the grilles is warm rather than hot, and the system runs longer at a time. This is normal: the house receives gentler, steadier heat. The thermostat must be designed for a heat pump with backup, so that the heat pump does the work first.
Avoid deep temperature setbacks at night or during the workday: to make up a large gap in the morning, the thermostat may call on the electric backup, which cancels part of the gain. A steady set point, or a modest setback, gives better results with a heat pump.
Maintenance
The cabinet filter is the first maintenance item: check it every month in season and replace it according to its format. Outside, keep a clearance around the outdoor unit, remove the snow that builds up after a storm and never cover it during the winter. The white vapour it gives off during defrost is normal.
One HVAC maintenance visit per year completes the picture: cleaning of the indoor and outdoor coils, condensate drain, electrical connections, check of operation in heating and cooling.
Warranty
Warranty: 10 years on the compressor, 10 years on parts and 6 years on labor.
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 N4H5S Performance | 1.5 Tons - 18,000 BTU (Air Handler FJMA4X) - R410A. We assess the home room by room and confirm the right size and your grant eligibility before signing.