FUJITSU CENTAURI R32 Central Heat Pump | 4 Tons - 48000 BTU

A 4-tonne power plant designed for our winters and our homes here

In Montreal , Laval , Longueuil , on the North Shore and the South Shore , a central heat pump is never a “standard” purchase. We are talking about a system that has to deal with very local realities: long winters, freeze-thaw cycles, brick houses that are sometimes not airtight, additions made at different times, ducts inherited from old furnaces, and high expectations of comfort (uniform temperature, low noise, less dry air, better air quality).

The FUJITSU CENTAURI R32 4-tonne (48,000 BTU) central heat pump precisely meets this type of need: a central ducted system capable of efficiently cooling in the summer, heating up to the typical cold temperatures here, and offering a coherent technical platform (efficiency, control, options, integrations).

At AirGreen, we especially recommend it when the project requires:

• a central solution for the whole house (not a room-by-room approach);

• the use or modernization of an existing conduit network;

• stable comfort on the floors (more homogeneous distribution);

• solid seasonal efficiency and compatibility with subsidy programs (in your product sheet: LogisVert provincial subsidy: $4,464 ).

Clear identification of the system (useful for subsidies, compliance and comparisons)

For this model, the technical specifications allow for quick validation of the pairing and performance:

• Model number (exterior): AOUH48KUAS1

• Model number (interior): AMUH48KUAS

• AHRI: 217290597

• ENERGY STAR®: Yes

• ENERGY STAR® (Cold Climate): Yes

• ENERGY STAR ID: 4428950

• Refrigerant: R-32

• Cooling capacity: 48,000 BTU

• Size: 4 tonnes

• Wi-Fi: optional

• Warranty (compressor – parts – labor): 12 – 12 – 0 years (extended warranty available)

This information may seem administrative, but in practice it makes life much easier: eligibility for programs, component compatibility, and fair comparison with other power plants.

Yield: what the numbers actually mean

We often see owners comparing systems based solely on performance "on a single line". However, what matters is performance over a full season and in a real-world context (House X, ducts Y, habits Z).

For this heat pump:

• SEER2: 17 (seasonal air conditioning efficiency)

• HSPF2: 9.6 / 7.8 (seasonal heating efficiency depending on region/test conditions)

• EER2: 9.5 (instantaneous air conditioning efficiency)

In a Montreal/Laval/Longueuil context, these values ​​indicate very interesting performance when the installation is done correctly: adjusted refrigerant charge, balanced ducts, optimized ventilation parameters, and controls configured according to the building.

Heating down to -21°C: why this is important here

The specifications indicate a heating capacity down to -21°C . This point is crucial: it means that the system is designed to remain functional and relevant for heating when the outside temperature becomes decidedly cold, thus reducing reliance on backup heating (or, at the very least, allowing for intelligent planning of backup heating).

In reality, good winter comfort doesn't depend solely on "withstanding -21°C". It also depends on:

• of the quality of the building envelope (insulation, air leaks);

• of the sizing (neither too big, nor too small);

• the capacity of the duct network to deliver hot air where it is needed, at the appropriate flow rate;

• of the backup strategy (if necessary) and control settings.

At AirGreen, we approach this issue in a very pragmatic way: a 48,000 BTU unit can be ideal, but only if it is aligned with the actual load of the house and the distribution capacity of the network.

Skills and useful benchmarks (for understanding behavior in cold weather)

Your product sheet mentions cold-weather power ratings:

• Rated power: 48,000 BTU

• Power at -8°C: 37,200 BTU

• Power at -15°C: 41,000 BTU

These figures are invaluable for "imagining" performance under real-world conditions, especially when comparing systems. They allow for a better understanding of how the machine behaves when the outside temperature drops, and for planning the entire system (ductwork, thermostat, backup heating, comfort on each floor).

Dehumidification and comfort: summer is not secondary

Heat pumps are often associated with heating, but in Montreal and the surrounding areas, summer requires special attention to humidity. Comfort doesn't just come from "lowering the temperature." It comes from less humid, more stable air and a properly regulated airflow.

The information sheet indicates:

• Dehumidification: 4.7 pt/h

In practice, the following combination transforms comfort:

• sufficient operating time (avoid excessively short cycles);

• an appropriate airflow (too much airflow can reduce dehumidification);

• a balanced distribution (well thought-out returns and outlets);

• consistent thermostat settings (reasonable deviations, no “yo-yo”).

Whether in an open-concept house on the South Shore or a multi-story cottage in Laval , it is often these details that make the client say: “We finally feel comfortable, even when it’s humid.”

Noise: what customers actually notice

A power plant can be quiet… or annoying, even if the technical specifications seem correct. The difference is made on the job site.

Your profile details:

• Sound pressure level (indoors): 34 / 51 dB(A)

• Sound pressure level (outdoors): 59.0 dB(A)

But the perceived noise depends mainly on:

• the quality of plenums and transitions (avoiding turbulence);

• the choice of grilles and the blowing speed;

• the anti-vibration mount;

• the location of the outdoor unit (proximity to bedrooms, echoing corners, clearances);

• balancing the ducts (an opening that is too “open” becomes noisy).

At AirGreen, we aim for overall comfort: temperature + noise + stability. A comfortable home is one where you don't hear the system struggling to circulate air.

From technical specifications to real-world comfort: ductwork, sizing and installation

Why a 4-ton truck isn't "just a big machine"

A 4-tonne (48,000 BTU) heater isn't automatically "too much" or "not enough." It becomes perfect or problematic depending on the building. Factors that affect the load:

• year of construction and level of insulation;

• fenestration (orientation, quality, surface);

• ceiling height, total volume;

• number of floors and air stratification;

• partial renovations (e.g., finished basement, extension, converted garage);

• occupancy habits (teleworking, high standards, rooms rarely closed).

A common mistake is to choose a capacity based solely on the surface area. Two houses of the same size can have completely different needs.

Conduits: the “invisible” part that determines the outcome

A high-performing central system depends on a coherent network of conduits. In the greater Montreal area, we regularly see:

• pipes inherited from an old oil-fired system or a less demanding furnace;

• undersized air returns;

• leaks in attic or crawl space sections;

• sections added “over time” without recalculating the flow rate.

Your profile indicates a high overall throughput (high CFM). In the real world, this means: if the network is restrictive, the system has to work harder, noise increases, and efficiency decreases.

Our approach to ductwork is structured:

1. Flow rate assessment per zone/room (depending on load and use).

2. Validation of static pressure (key indicator of an overly restrictive network).

3. Optimization of air returns (often the most neglected element).

4. Sealing and insulation of ducts (especially in unheated areas).

5. Final balancing : we adjust so that the house is uniform, not just “cold near the return”.

Installation details that matter (and that you can't see in a photo)

Your information sheet mentions several practical elements:

• Piping: 3/8 – 5/8

• Voltage: 220 V

• MCA: 30 A

• MOP: 30 A

• Interior dimensions: 21 x 21 x 48 in

• External dimensions: 31 x 12.63 x 37 in

This data becomes concrete during installation:

• available space in the mechanical room (or attic);

• access for maintenance (clearances, hatches, doors);

• outdoor location which limits noise and snow accumulation;

• passage of refrigeration lines (mechanical protection, slope, insulation);

• drainage (slope, access, backflow prevention);

• electrical compliance (size, protections, circuit breaker).

At AirGreen, we do not treat these points as formalities: they are conditions that influence durability, performance and maintenance.

Commissioning: where performance is "earned"

A central heat pump can be excellent, but if the commissioning is botched, the results won't follow. Our commissioning process aims to:

• circuit leak test;

• stable vacuum;

• final adjustments (temperatures, pressures, complete operation);

• validation of fan speeds according to the network;

• verification of protections and defrosting behavior;

• Clear documentation and recommendations to the client (filters, maintenance, best practices).

It is often at this stage that we avoid the “small problems” that become irritating: blowing noise, discomfort in a room, insufficient dehumidification, cycles that are too short.

Controls, thermostat and options: comfort also comes from logic

A central heating system is more than just an outdoor unit and a coil: the control system directly influences stability, energy consumption, and comfort. Depending on the situation, we guide customers towards:

• a central control system consistent with the building;

• the Wi-Fi option if it provides real value (remote management, schedules, instructions);

• A realistic setpoint strategy: avoid abrupt increases/decreases, which force inefficient cycles.

The goal: a system that works “calmly”, for a long time and efficiently, rather than a system that starts and stops constantly.

AirGreen case studies: three typical scenarios involving around 4 tonnes

1) Montreal – renovated duplex, uneven comfort between floors
The owner noted a comfortable ground floor, but an upper floor that was too hot in the summer and too cold in the winter. The solution wasn't "more power." We have:

• optimized air return;

• corrected overly restrictive duct sections;

• adjusted the balance of the mouths;

• adjusted the ventilation speeds to stabilize the diffusion.
  Result: the house became more uniform, and the client especially noticed the nighttime stability (more constant temperature in the bedrooms).

2) Laval – cottage with finished basement and open concept
Here, the challenge was the layout: an open area requiring plenty of air and a basement that is often more humid. We have:

• validated static pressure and identified bottlenecks;

• made targeted corrections to the network;

• recalibrated the balancing to avoid "over-serving" certain areas.
  The customer noted improved comfort in the basement, and more stable air conditioning on humid days.

3) Longueuil – exposed house, supplementary strategy framed
The house was very exposed to the wind, with adequate insulation but demanding performance in extreme cold. We have:

• clarified the low-temperature heating strategy;

• recommended a properly sized supplement (if needed);

• configured the control to avoid unnecessary toggles.
  The result: predictable comfort, fewer temperature variations, and a system that remains “logical” even during very cold periods.

Common mistakes to avoid with a central heat pump

• Oversizing for reassurance : short cycles, less stable comfort, less effective humidity management.

• Undersizing for economic reasons : excessive use of backup heating, discomfort in cold weather, system strain.

• Ignoring conduits : a problematic network can negate much of the benefit of a high-efficiency machine.

• Placing the outdoor unit in the wrong location : noise near bedrooms, air recirculation, snow accumulation, difficult access.

• Neglecting filtration and maintenance : reduced flow rate, noise, higher consumption, premature wear.

Maintenance: simple, but non-negotiable

To maintain the performance of a central heat pump :

• check and replace/clean the filters according to the recommended frequency;

• inspect the drainage and pipes (prevent blockages);

• plan a periodic maintenance visit (measurements, inspection, cleaning as needed);

• check the condition of the connections, the insulation of the lines, and the defrosting behavior.

Regular maintenance means fewer surprises, better efficiency, and a longer lifespan.

Questions that homeowners often ask (and our answers on the ground)

Is a central unit better than a wall-mounted one?
It's not a question of "best": it's a question of use. A central unit excels at even distribution , especially in homes with ductwork. A wall-mounted unit is often better suited to specific areas or homes without ductwork. For an entire house, a central unit provides a more consistent feel.

Is 4 tonnes too much for a house in Montreal?
Sometimes yes, sometimes no. It all depends on the load, losses, window placement, volume, number of floors, and network. That's precisely why an on-site assessment and technical validation make all the difference.

What difference does R-32 make to me?
For the owner, the main benefit is having a modern system, aligned with current trends in refrigerants, while maintaining very good performance.

Why does my neighbor have the same capacity but not the same comfort?
Because capacity is only part of the equation. Conduits, returns, balancing, adjustments, insulation and commissioning determine the final result.

What we do differently at AirGreen

Installing a FUJITSU central heat pump is not simply a matter of "installing a machine." Our job is to deliver a complete result: comfort , stability , performance , and a seamless customer experience.

In practical terms, this means:

• a serious reading of the building (load, zones, actual constraints);

• attention to the network of pipes (flow rate, returns, balance, sealing);

• a rigorous commissioning (the final adjustments make a real difference);

• clear communication: what is being done, why, and how to maintain it.

We also emphasize very concrete points that reassure our clients:

• Free on-site estimate : seeing the network and constraints changes everything.

• Transparent pricing : final offer before work begins, no surprises.

• Experienced professional refrigeration technicians : efficient installation and after-sales service.

• Payment at the end : you pay when you are satisfied.

Conclusion and Next Steps!

If you are considering a 4-tonne, 48,000 BTU central heat pump in Montreal , Laval , Longueuil , on the North Shore or South Shore , the FUJITSU CENTAURI R32 is a particularly relevant choice when you are looking for a central ducted solution, uniform comfort and consistent year-round performance.

Contact AirGreen for an on-site estimate: we validate capacity, ductwork, location, control options, and the best heating/cooling strategy for your home.
Phone: 514-316-2973 — Email: sales@airgreen.ca