Central Heat Pump ADD-ON ARCOAIRE H4H5S ION | 4 Tons - 48,000 BTU (Coil EVD4X 24.5 in.) - R410A

From the first visit to commissioning, a 4-ton ADD-ON step by stepThe ADD-ON system adds a heat pump to an existing electric furnace: a coil is installed on the furnace and the outdoor unit heats and cools through the same ducts. The furnace's electric elements are only used as backup. The Central Heat Pump ADD-ON ARCOAIRE H4H5S ION | 4 Tons - 48,000 BTU (Coil EVD4X 24.5 in.) - R410A pairs the H4H5S48AKAAA outdoor unit with the EVD4X48M24A coil.Adding a heat pump to an electric furnace is a well-defined project: the furnace and the ducts stay, and the work covers the coil, the outdoor unit, the line set, the electrical work and the thermostat. Each step still has to be done in the right order. Here is how a project unfolds with us, from the first visit to the moment the system runs on its own.Before the visit: what helps usA few details, if you have them at hand, make the visit more efficient:a photo of the furnace's rating plate, which shows its brand and model;its approximate age and the invoices from its last maintenance visits;a photo of the electrical panel with the door open;the rooms that bother you: hot bedrooms in summer, cold rooms in winter, a damp basement;the house plans, if any exist.The home visitDuring the visit, we look at the house as a system. In the basement: the condition of the electric furnace and its heating elements, the width of its cabinet, its blower, the clearance above it and the plenum. In the house: the registers, the returns and how the duct system serves each level. Outside: the possible location of the outdoor unit, the snow line, roof drip, neighbouring windows. At the panel: the space and capacity available for a dedicated circuit, on top of what the furnace already draws.We also look at the current thermostat and the cable that connects it to the furnace. A heat pump thermostat that also manages auxiliary heat often needs more conductors than an ordinary furnace thermostat; if the existing cable is not enough, we plan to run a new one. And if the furnace shows signs of advanced wear, we tell you during the visit: an ADD-ON only makes sense on a reliable furnace.The load calculation and choosing the sizeThe load calculation is done room by room: windows, orientation, insulation, airtightness, occupants. In an ADD-ON, the furnace's electric elements cover the deep cold, so we size the heat pump on the cooling load. An oversized unit cools in short cycles and removes humidity poorly; an undersized unit struggles on heat-wave afternoons.The 4-ton size often suits a large two-level house with a finished basement, a heavily glazed house or an extended house in Laval or on the North Shore. These examples are only a guide: the calculation decides. The H4H5S48AKAAA unit is part of Arcoaire's ION series, and the EVD4X48M24A coil, a 24.5 in. format, is shared by the series of this size.The written quoteThe quote specifies the chosen equipment, the model numbers of the outdoor unit and the coil, the related work planned and the confirmed ratings of the pairing. If the plenum must be rebuilt, if a return is recommended or if the panel needs a modification, it is written down in black and white before you sign. You know exactly what will be done, and why. If the grant matters to you, we can also present an eligible option of comparable size alongside this pairing.System ratingsThe pairing of the H4H5S48AKAAA outdoor unit and the EVD4X48M24A coil is not listed with SEER2 ratings in the AHRI certification directory. We confirm the ratings of the complete system before the quote; they also determine grant eligibility.That is why no rating appears on this page: the confirmed ratings are in the quote.LogisVertThis 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 on the existing furnaceThe coil sits on the furnace's air outlet, and a compatible thermostat decides when the heat pump heats alone and when the electric furnace takes over. We check the condition of the furnace, the airflow of its blower and the duct sizes before the quote. The outdoor unit goes on a stand, above the snow line, on a dedicated circuit.Installation dayOld equipment: if there is an old air conditioner, its refrigerant is recovered before the unit and its coil are removed.Coil: installation of the 24.5 in. coil on the furnace's air outlet, with a sealed sheet-metal transition if the widths differ, then adjustment of the plenum.Drain: connection of the condensate drain, with a trap, to the floor drain or a pump.Outdoor unit: installation of the stand and the unit, out of roof drip and away from bedroom windows.Line set: routing of the insulated line set through a sealed opening, joints brazed under nitrogen.Electrical: dedicated circuit, outdoor disconnect and control wiring between the unit, the furnace and the thermostat.Thermostat: installation of the heat pump thermostat, which also controls auxiliary heat, and, where applicable, its outdoor sensor.CommissioningCommissioning checks that everything just installed works together. The refrigerant line set undergoes a nitrogen pressure test, then a vacuum; the R-410A charge is then adjusted according to the manufacturer's instructions. We set the furnace blower speed for cooling and heat pump heating, then the point at which the thermostat brings in the furnace's electric elements, according to the house and your preferences.Each mode is then tested: cooling, heat pump heating, auxiliary heat from the furnace's elements, emergency heat, and the changeover from one to the other. Finally, we check the condensate drain flow.After the installation: what you will noticeIn winter, the heat pump heats alone in cool weather, and the furnace's electric elements add auxiliary heat when the cold deepens. The heat pump's air is less hot than the air from the elements and its cycles are longer; the house stays at a more even temperature. During defrost, a plume of white vapour comes out of the outdoor unit and the furnace's elements may come on briefly. In summer, the same unit cools and dries the whole house through the ducts.We show you how to read the thermostat, change the auxiliary heat threshold and replace the filter. Keep the quote and the invoice: they describe the installed equipment and will be useful during maintenance visits.MaintenanceReplace 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 electric furnace keeps its usual maintenance: blower, heating elements and connections. Its elements run fewer hours than before, but they must stay ready for the very cold days.AirGreen, for the life of the installationA 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 ADD-ON ARCOAIRE H4H5S ION | 4 Tons - 48,000 BTU (Coil EVD4X 24.5 in.) - R410A. We assess the home room by room and confirm the right size and your grant eligibility before signing.Available while supplies last.Warranty: 10 years on the compressor, 10 years on parts and 6 years on labor.