Central Heat Pump CONFORTO MHSD | 4 Tons - 48,000 BTU - R410A

A large home heated and cooled by a single central system

Beyond a certain size, choosing a central heat pump is no longer just about the unit. The electrical service, the duct system and the distribution of air between floors also have to keep up. The Central Heat Pump CONFORTO MHSD | 4 Tons - 48,000 BTU - R410A pairs the MHSD148DACFC outdoor unit with the MHAH148DACFC indoor unit, an air handler that replaces the furnace and pushes air through the entire existing duct system.

Its certified ratings are 15.6 SEER2, 8.2 EER2 and 9.4 HSPF2. The system is ENERGY STAR certified with the cold-climate designation under ENERGY STAR ID 3892549, its certificate still lists capacity at -30 °C, and it qualifies for a $4,320 LogisVert grant.

The homes a 4-ton system is meant for

The 4-ton size, or 48,000 BTU/h, is meant for large homes: a two-storey cottage with a large finished basement, an upscale home on the North Shore or the South Shore, a large older house in Montreal with many rooms and high ceilings. These are often homes whose furnace and air conditioner were also large.

This size should not be repeated out of habit. A renovated home, with a re-insulated attic and recent windows, may have needs well below those of the old unit. Conversely, an older home with poorly insulated walls can reach this size sooner than expected. A load calculation, room by room and floor by floor, settles it before any quote.

One system or two

In some large homes, two smaller systems, each with its own duct system and thermostat, work better than one big system: for example when the upper floor and the main floor have separate duct systems, or when one wing of the house is occupied at different times. In others, a single properly sized system with a balanced duct system is the simplest and most durable solution. During the visit, we examine the duct layout and present the option that suits your home.

The electrical service, the first check

A 4-ton system requires a matching electrical supply. The outdoor unit needs its dedicated circuit, and the electric backup, usually housed in the indoor unit in an all-electric installation, adds a significant load during deep cold. Together, they must coexist with the range, the water heater, the dryer and, more and more often, an electric vehicle charger.

Before the quote, we check the capacity of the electrical service and the space available in the panel. If an upgrade is needed, it is stated in the written quote, before signing, to avoid any surprise on installation day. We also size the backup heat from the load calculation, no more and no less than what the house requires.

Ducts sized for the airflow

The bigger a heat pump, the more air it has to move. An undersized or poorly connected duct system forces it to work against excessive resistance: the blower gets noisy, air whistles at the registers and efficiency drops. During the visit, we examine the main trunk, the branches, the number of registers and above all the air return, often the weak point in large homes.

Distribution between floors matters just as much. An upstairs return, balanced branches and a well-placed thermostat keep the upstairs bedrooms from overheating in winter or staying warm in summer while the basement is cold. Useful corrections are included in the quote.

How it works: variable speed and R-410A

The heat pump moves heat instead of producing it. In winter, the R-410A refrigerant captures heat from the outdoor air and brings it to the indoor unit's coil; in summer, a reversing valve flips the cycle. The variable-speed (inverter) compressor adjusts its speed to demand: in a large home, it spends most of the year at part load and only reaches full capacity on the coldest or hottest days.

Winter according to the certificate

• At -8 °C (17 °F): 36,000 BTU/h, with a COP of 2.36.
• At -15 °C (5 °F): 46,000 BTU/h, with a COP of 1.90, about 96% of the nominal size.
• At -30 °C: 24,500 BTU/h, with a COP of 1.37.

The -8 °C and -15 °C points are measured separately; we report each one as published. These figures come from certificate AHRI 216683752, published by NEEP. COP compares the heat delivered with the electricity used: an electric baseboard has a COP of 1, and this heat pump stays above that threshold down to -30 °C. Below the point where the house loses more heat than the heat pump supplies, backup heat takes over.

The ratings and cooling

The HSPF2 of 9.4 measures efficiency over the whole heating season, the period that weighs most on the bill of an electrically heated home. The SEER2 of 15.6 measures cooling efficiency over a typical summer, at part load most of the time. The EER2 of 8.2 measures full-load efficiency on a very hot day; it is more modest, which means this system performs at its best in heating and on ordinary summer days.

In summer, the system cools every room served by the ducts, from the basement to the bedrooms. By running for long periods at low speed, it removes moisture from the air, a real advantage in a large finished basement. Condensate drains from the indoor unit to a floor drain or a pump.

The $4,320 LogisVert grant

The system is listed in Hydro-Québec's LogisVert program, with $4,320 for the owner of an existing home, according to the list in effect on the installation date. The amount corresponds to the certified pairing of the MHSD148DACFC outdoor unit and the MHAH148DACFC indoor unit.

We confirm eligibility before signing and prepare the detailed invoice, model numbers and proof of payment. Our page on the efficient heat pump grant summarizes the program's conditions.

Installation by AirGreen

How the job unfolds

The visit includes the load calculation, a complete inspection of the duct system, a check of the electrical service and the choice of the outdoor location. A unit of this size is bulky: we choose a location that lets air circulate around it, above the snow line, on a stand or bracket suited to its weight, away from roof drip and bedroom windows.

On installation day, the furnace is removed and the air handler takes its place, connected to the plenum, the air return and the drain. The insulated copper line set is brazed, pressure-tested and put under vacuum. The electrical connection is made on a dedicated circuit, with an outdoor disconnect, and the thermostat is replaced or wired in. Commissioning checks the charge, airflow, defrost and backup heat, and then we explain the settings to you.

Maintenance

Check the indoor unit's filter every month in season and replace it according to its format: in a system with this much airflow, a clogged filter is quickly felt. Keep the outdoor unit clear of snow and leaves, without covering it. Annual HVAC maintenance cleans the coils and checks the condensate drain, the electrical connections and the backup heat. In winter, the white vapour during defrost is normal.

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 CONFORTO MHSD | 4 Tons - 48,000 BTU - R410A. We assess the home room by room, check the electrical service and the ductwork, and confirm the right size and your grant eligibility before signing.