FORESTAIT MZ R454B 3-Zone Wall-Mounted Heat Pump | Ext: 42000 BTU
The ForestAir MZ R454B 42 000 multi-zone heat pump heats and cools 3 rooms with a single outdoor unit. it delivers 31,000 BTU/h at −8 °C, heats down to −25 °C and qualifies for a $3,720 LogisVert grant. Installed by AirGreen in Montréal, Laval, Longueuil, the North Shore and the South Shore.
3 rooms, one outdoor unit.
Compared with the 86 multi-zone systems of 42,000 BTU we sell. Every number on this page carries its source.
The parts that make a multi-zone system.
Tap a part to learn more.
Outdoor unit
One compressor for the whole house. It supplies up to 5 heads and modulates from 6,500 to 32,000 BTU/h depending on what the rooms call for (NEEP).
Base pan heater
A heater keeps the outdoor unit’s base pan free of ice below 1 °C and during defrost (NEEP).
Refrigerant lines
One pair of lines per head.
Indoor heads
One head per room, each with its own remote and temperature. The combination is chosen in the “Zones” menu.
Control
Each zone is set separately, also from your phone.
Turn rooms on and off. Watch the power being shared.
One outdoor unit supplies every head: when several rooms call at once, they share its capacity. Pick an outdoor temperature.
Tell us your rooms. We tell you if this size is enough.
Pick the number of rooms and their size. The estimate targets a −15 °C day; it is a guide, the real calculation is done room by room at your home.
The whole series at a glance: find the box that fits you.
Each box is a product: the outdoor unit’s size, and the number of heads.
At −15 °C, it still delivers 71 % of its rated capacity.
Tap a temperature: certified capacity, efficiency and the cost of one hour of heating.
It slows down, it speeds up: the certified modulation range
Light bar: from minimum to maximum capacity. Dark mark: the rated value.
At every temperature, cheaper than baseboards.
Cost of one hour at full output, for the same heat delivered. Hydro-Québec Rate D, second tier: 11.142 ¢/kWh.
The official ratings, on the same scales as before.
SEER2, HSPF2 and EER2 come from the AHRI certification. The mark shows the median of the same-size multi-zone systems we sell.
A grant you can calculate, not guess.
The capacity at −8 °C comes from Hydro-Québec’s list of October 1, 2026. $120 per 1,000 BTU/h is the rate for ENERGY STAR cold-climate heat pumps (guide v1.10).
Where it ranks among same-size multi-zone systems.
Compared with the 86 multi-zone systems of 42,000 BTU we sell, using the LogisVert list figures. Weaknesses too, said plainly.
Against three other brands in its class.
Same rated size, other manufacturers. Pick the opponent.
One multi-zone or several wall units? Both sides, honestly.
We compare both options on your floor plan during the estimate.
What to know before installing a multi-zone system.
Dimensions, wiring and lines, drawn. Then our six steps.
The outdoor unit, dimensioned
One circuit for the whole house
Published sound levels, on one scale.
We use the outdoor figure to choose where the unit goes.
What is particular about this machine.
Only facts published by ENERGY STAR, NEEP or the manufacturer.
Every number, and where it comes from.
Each line carries its source; a line with no published value is not shown.
The manufacturer’s documentation, as PDF.
Everything we have written about this system.
A High-Performance Multi-Zone HVAC Solution Designed for Quebec's Climate
In a context where heating and air conditioning needs vary from room to room, the FORESTAIR MZ R454B 42,000 BTU 3-zone wall-mounted heat pump stands out as a highly efficient and flexible solution. At AirGreen, we regularly install this type of system in homes, plexes, and condos in Montreal, Laval, Longueuil, on the North Shore, and the South Shore, precisely because it allows independent control of multiple zones while optimizing energy consumption.
This model is particularly interesting for properties where a central system is not possible or desired. Thanks to its 42,000 BTU capacity, it can power up to 3 main zones (and up to 5 zones maximum), offering great configuration flexibility depending on the building's layout.
Why Choose a FORESTAIR Triple-Zone Heat Pump in Montreal and Surroundings
Reliable Performance Even in Quebec Winters
One of the key elements that distinguishes this heat pump is its ability to operate efficiently down to -25°C, which is essential in cities like Montreal or Laval, where winters are harsh. Unlike some entry-level systems, this model maintains stable heating power:
- 31,000 BTU at -8°C
- 30,000 BTU at -15°C
This concretely means that even during cold snaps, you maintain constant comfort without excessively relying on auxiliary heating.
According to the manufacturer's technical sheet, the heating operating range extends down to -25°C, with intelligent defrost technology that optimizes operating cycles in winter conditions.
Superior Energy Efficiency to Reduce Your Costs
This system is ENERGY STAR® certified (including Cold Climate), making it eligible for significant subsidies, notably the LogisVert program (up to $3720).
Here are its main performance indicators:
- SEER2: 22.0 (high-efficiency cooling)
- HSPF2: 10.0 (efficient heating)
- EER2: 11.2
- COP: 3.50
In practice, this means:
- A noticeable reduction in your electricity bill
- Improved thermal stability in each zone
- Rapid return on investment after installation
At AirGreen, we have observed annual savings of up to 25 to 35% compared to traditional electric systems in several installations in Longueuil and Boucherville.
Multi-zone Configuration: Tailor-Made Comfort Room by Room
Exceptional Installation Flexibility
This heat pump allows connecting different indoor units, for example:
- 9,000 BTU for a bedroom
- 12,000 BTU for an office
- 18,000 or 24,000 BTU for a living room or open area
Compatible models include:
- FA-H09-D24TL-I-454
- FA-H12-D24TL-I-454
- FA-H18-D24TL-I-454
- FA-H24-D24TL-I-454
This allows perfect adaptation to each room, without unnecessary overconsumption.
Real AirGreen Installation Example
We recently installed this model in a duplex in Ahuntsic (Montreal):
- 3 distinct zones (living room + 2 bedrooms)
- Old system: electric baseboards + portable air conditioner
- Result:
- Significantly improved comfort
- Noise reduction
- Hydro-Québec bill reduction of approximately 30%
The client wanted to avoid an expensive and intrusive central system. The FORESTAIR multi-zone solution proved ideal.
Advanced Technology and Technical Specifications
DC Inverter Compressor and Smart Operation
The system uses DC Inverter technology, which means:
- Continuous power adjustment
- Fewer ON/OFF cycles
- Improved longevity
- Constant thermal comfort
Intelligent defrost also optimizes performance in winter, reducing efficiency losses.
Important Technical Data
Outdoor unit:
- Dimensions: 42.25 x 33.63 x 18.38 in
- Sound level: 65 dB(A)
- Airflow: 3200 m³/h
- Voltage: 208-230V / 1 phase / 60 Hz
- MCA: 28A | MOP: 45A
Refrigerant: R-454B
- More environmentally friendly than previous generations
- Reduced environmental impact
Refrigeration installation:
- Total maximum length: 90 m (295 ft)
- Length per zone: 30 m (98 ft)
- Pre-charge: 37.5 m (123 ft)
This data allows for complex installations, particularly in multi-story houses or multiplexes.
HVAC Installation: Mistakes to Avoid (AirGreen Field Experience)
Poor Zone Distribution
A common mistake is to oversize one zone and undersize another. The result:
- Thermal discomfort
- Premature wear
- Poor energy efficiency
At AirGreen, we always perform a complete thermal analysis before any installation.
Incorrectly Calculated Pipe Length
Exceeding recommended lengths can lead to:
- Loss of performance
- Pressure issues
- Additional costs
Thanks to our expertise in HVAC installation in Montreal and on the South Shore, we always optimize the routing to comply with manufacturer standards.
System Maintenance and Durability
To maintain performance:
- Filter cleaning every 2-3 months
- Annual inspection recommended
- Refrigerant level check
Regular maintenance extends the system's lifespan and preserves its energy efficiency.
Why Choose AirGreen for Your FORESTAIR Heat Pump
Recognized Local Expertise
- Installations carried out throughout Montreal, Laval, Longueuil, North Shore, and South Shore
- Certified and experienced technicians
- Valid RBQ + $5M liability insurance
Transparency and Full Support
- Clear and detailed quote
- No surprises at the end
- Support for subsidies (LogisVert)
Efficient After-Sales Service
- Fast support
- Availability during critical periods
- Quick parts and diagnostics
Conclusion: A Balanced Solution Between Performance, Flexibility, and Efficiency
The FORESTAIR MZ R454B 42,000 BTU 3-zone wall-mounted heat pump represents a solid option for homeowners seeking a high-performance multi-zone system, adapted to Quebec's climatic realities.
It combines:
- High energy efficiency
- Heating capacity down to -25°C
- Installation flexibility
- Attractive subsidies
At AirGreen, we recommend this model for many residential and multi-dwelling cases, especially when room-by-room comfort is a priority.
Contact AirGreen Today
Do you want to get a price, confirm your eligibility for subsidies, or schedule a heat pump installation in Montreal, Laval, Longueuil, or on the North Shore / South Shore?
Contact us now. Our team will guide you towards the HVAC solution best suited for your property.
Warranty: 10 years on the compressor, 10 years on parts and 6 years on labor, straight from the distributor.
What people ask us about multi-zone systems.
Can I heat one room and cool another at the same time?
No. On a multi-zone system like this one, every head works in the same mode, heating or cooling. Each room still keeps its own set temperature.
What happens when every room calls for heat?
They share the outdoor unit’s capacity: 31,000 BTU/h at −8 °C, 30,000 at −15 °C.
How many heads can I connect?
Up to 5 on this outdoor unit. This product is configured for 3 heads.
How much is the LogisVert grant?
$3,720 according to Hydro-Québec’s list of October 1, 2026. The grant never exceeds 100 % of the cost before taxes; apply within 9 months of installation.
Is it ENERGY STAR certified?
Yes, cold climate, ID 4529626. It also meets the ENERGY STAR Most Efficient criteria, according to the ENERGY STAR database.
Down to what temperature does it heat?
Down to −25 °C.
Is it noisy?
Indoors, the reference head goes down to 30 dB(A). Outdoors, 65 dB(A): we place the unit away from bedroom windows.
Why a multi-zone instead of several wall units?
One outdoor unit on the wall and one circuit. In return, the rooms share the capacity, and if the outdoor unit stops, every zone stops.
What does the warranty cover?
Our sheet lists 10 years on the compressor and 10 years on parts. AirGreen extended warranty: possible.
A multi-zone system is planned room by room. At your home.
We measure every room, draw the line route and choose the right head for each zone. The on-site estimate is free and the quote arrives within 24 h.