FORESTAIR MZ R454B 3-Zone Wall-Mounted Heat Pump | Ext: 36000 BTU
The ForestAir MZ R454B 36 000 multi-zone heat pump heats and cools 3 rooms with a single outdoor unit. it delivers 27,400 BTU/h at −8 °C, heats down to −25 °C and qualifies for a $3,288 LogisVert grant. Installed by AirGreen in Montréal, Laval, Longueuil, the North Shore and the South Shore.
3 rooms, one outdoor unit.
Compared with the 141 multi-zone systems of 36,000 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 4 heads and modulates from 5,500 to 27,500 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 72 % 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 141 multi-zone systems of 36,000 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 adapted to Quebec's climate
In the demanding climatic context of Montreal, Laval, Longueuil, the North Shore, and the South Shore, the choice of a multi-zone HVAC system must meet precise criteria: real energy efficiency, heating performance at very low temperatures, installation flexibility, and long-term reliability. At AirGreen, we regularly install systems like the FORESTAIR MZ R454B 36,000 BTU 3-zone wall-mounted heat pump, precisely because it meets these on-the-ground requirements.
This model is particularly aimed at owners of houses, plexes, condos, or multi-unit dwellings who wish to air condition and heat several spaces independently, while maintaining a single outdoor unit.
Why the FORESTAIR MZ 36,000 BTU is a strategic choice
Flexible multi-zone configuration (up to 4 zones)
This heat pump allows connecting up to 4 indoor units, offering great layout freedom. In practice, this means:
- A bedroom with independent control
- A living room with higher capacity
- An office or basement with personalized management
In several projects completed in Boucherville and Laval, we used this flexibility to replace inefficient electric systems with a single centralized solution, while maintaining room-by-room comfort.
Real performance in Quebec winters
One of the most important criteria remains heating performance. This model offers:
- Heating capacity down to -25°C
- 27,400 BTU at -8°C
- 26,000 BTU at -15°C
These data are not theoretical. They correspond to realistic conditions for Montreal and Montérégie. According to the technical sheet, the heating operation range goes down to -25°C, confirming its compatibility with local winters.
At AirGreen, we installed this system in a triplex in Longueuil, where the client sought to completely eliminate electric baseboards. Result: significant reduction in energy bills from the first winter.
Certified energy efficiency and available subsidies
This heat pump is:
- ENERGY STAR® certified
- Cold Climate ENERGY STAR®
- SEER2: 22.5
- HSPF2: 10.0
- COP at -8°C: 3.5
These performances allow access to significant subsidies, notably:
- LogisVert Program: up to $3,288
In several installations on the North Shore, our clients have recovered a significant portion of their investment through these programs.
New R-454B refrigerant: more ecological
The transition to R-454B represents a significant evolution in the HVAC industry:
- Significant reduction in global warming potential (GWP)
- Improved thermodynamic efficiency
- Compliance with future environmental standards
At AirGreen, we are already prioritizing these systems to anticipate upcoming regulations in Quebec.
Essential technical data to know
Capacities and performance
- Nominal power: 36,000 BTU
- Actual cooling capacity: 35,000 BTU
- Heating capacity: 36,000 BTU
- Outdoor airflow: 3200 m³/h
- Outdoor sound level: 65 dB(A)
Installation and electrical requirements
- Voltage: 208-230V / 1 phase / 60 Hz
- MCA: 22A
- Recommended breaker: 35A
These elements are crucial for a compliant installation. In several projects in Montreal, we had to adapt the electrical panels to meet these requirements.
Piping and maximum distances
- Liquid line: 1/4"
- Gas line: 3/8"
- Maximum total length: 80 m (263 ft)
- Maximum length per zone: 30 m (98 ft)
- Maximum vertical difference: 10 m (33 ft)
These characteristics make the system particularly suitable for:
- Multi-story houses
- Duplexes and triplexes
- Properties with finished basements
AirGreen experience feedback: actual installation in Laval
We recently installed this model in a single-family home in Laval (Chomedey) with the following constraints:
- Three distinct zones (living room, master bedroom, basement)
- Long distance between outdoor unit and basement
- Client wishing to minimize noise
Challenges encountered
- Piping run over a long distance
- Drainage optimization
- Choice of suitable indoor units (9K, 12K, and 18K)
Result
- Perfectly balanced installation
- Very low indoor sound level (≈ 30 dB in low mode)
- Stable heating even during intense cold periods
Common mistakes to avoid with a multi-zone system
1. Improper BTU distribution
Many clients think it's enough to divide the 36,000 BTUs equally. In reality:
- Each room has different needs
- Orientation, insulation, and volume influence capacity
At AirGreen, we always perform a complete thermal analysis.
2. Underestimating piping length
Incorrect calculation can:
- Reduce efficiency
- Increase installation costs
- Affect overall performance
3. Neglecting HVAC maintenance
Even with a high-performance system:
- Mandatory filter cleaning
- Recommended annual inspection
- Refrigerant check
This is particularly important in cities like Montreal and Longueuil, where climatic variations are significant.
Why choose AirGreen for this installation
Recognized local expertise
- Concrete experience in HVAC installation in Montreal, Laval, South Shore, and North Shore
- Mastery of complex multi-zone systems
- Adaptation to Quebec's climatic realities
Transparency and precision
- Detailed quotes
- No hidden costs
- Realistic technical advice
Optimized installation
- Precise sizing
- Customized configuration
- Complete commissioning
Reliable after-sales service
- Quick support
- Qualified technicians
- Structured customer follow-up
Conclusion: a heat pump adapted to demanding multi-zone projects
The FORESTAIR MZ R454B 36,000 BTU 3-zone wall-mounted heat pump represents a solid solution for properties requiring independent management of multiple spaces.
It combines:
- Heating performance down to -25°C
- High energy efficiency
- Multi-zone flexibility
- Modern technology with R-454B
At AirGreen, we recommend this model for residential and multi-unit projects requiring a reliable, adaptable, and high-performing system in Quebec's climatic conditions.
Contact AirGreen for your HVAC project
Looking to install a multi-zone heat pump in Montreal, Laval, Longueuil, on the North Shore, or the South Shore?
Our team supports you every step of the way:
- Personalized assessment
- Choice of suitable system
- Professional installation
- Access to available subsidies
Contact us today for a detailed quote and optimize your comfort all year round.
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: 27,400 BTU/h at −8 °C, 26,000 at −15 °C.
How many heads can I connect?
Up to 4 on this outdoor unit. This product is configured for 3 heads.
How much is the LogisVert grant?
$3,288 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 4529625. 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.