FORESTAiR MZ R454B 4-Zone Wall-Mounted Heat Pump | Ext: 36000 BTU
The ForestAir MZ R454B 36 000 multi-zone heat pump heats and cools 4 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.
4 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 solution designed for Quebec's climate
In the field of residential HVAC in Montreal, Laval, Longueuil, and on the North and South Shores, needs are evolving rapidly, especially for multi-room homes, plexes, and renovation projects. The FORESTAIR MZ R454B 36,000 BTU 4-zone wall-mounted heat pump stands out as a particularly effective solution for providing precise temperature control in multiple spaces while maintaining excellent energy efficiency.
At AirGreen, we regularly install this type of multi-zone system in residences where individual room comfort is a priority. This model is distinguished not only by its ability to power up to 4 independent zones but also by its performance adapted to Quebec's harsh winters.
Why choose a multi-zone heat pump like the FORESTAIR MZ R454B?
Ideal flexibility for modern properties
Unlike traditional systems, this multi-zone heat pump allows up to 4 indoor units to be connected to a single outdoor unit. This means:
- Independent temperature control in each room
- Reduced installation costs compared to multiple separate systems
- Better overall energy management
We recently installed this model in a house in Boucherville (South Shore) where the client wanted to air condition a living room, two bedrooms, and an office without multiplying outdoor units. The result: a discreet, high-performance system perfectly suited to the configuration.
Impressive performance even in winter
One of the critical points for customers in Montreal and Laval remains heating performance. This FORESTAIR model offers:
- Efficient heating down to -25°C
- Heating capacity at -15°C: 26,000 BTU
- Capacity at -8°C: 27,400 BTU
According to the manufacturer's technical data, the system operates in a heating range down to -25°C, making it a reliable solution even during Quebec's coldest periods.
Energy efficiency and concrete savings
ENERGY STAR® (Cold Climate) certified performance
This system is ENERGY STAR® and ENERGY STAR® Cold Climate certified, which means:
- SEER2: 22.5 (very efficient cooling)
- HSPF2: 10.0 (excellent heating efficiency)
- COP: 3.5
In practice, this results in:
- Significant reduction in electricity bills
- Eligibility for subsidies like LogisVert ($3288)
- Improved performance stability throughout the year
We have observed among several clients in Laval and Longueuil a consumption decrease of up to 30% after replacing an old electric system.
Advanced technology and optimal comfort
High-efficiency DC Inverter compressor
The system uses DC Inverter technology, which allows for:
- Automatic power adjustment based on needs
- Fewer on/off cycles
- Improved compressor durability
This directly impacts indoor comfort: the temperature remains stable, without unpleasant fluctuations.
Quiet operation and compact design
- Outdoor sound level: 65 dB(A)
- Compact design facilitating installation
In several installations in Montreal (Rosemont, Plateau, Ahuntsic), we have integrated this model into confined spaces without compromising aesthetics or acoustic comfort.
Integrated WiFi and smart control
The system includes WiFi, allowing for:
- Remote control via application
- Temperature scheduling
- Consumption optimization
A client in Saint-Lambert uses this feature to automatically adjust temperatures according to their work schedule, further reducing their energy costs.
Essential technical details to know
Configuration and installation
- Voltage: 220V / 208-230V / 1 phase / 60 Hz
- MCA: 22A
- MOP: 35A
- Maximum total piping length: 80 m (263 ft)
- Maximum length per unit: 30 m (98 ft)
These features offer great installation flexibility, particularly useful in large properties or multi-story homes.
Piping and HVAC installation
- Liquid line: 1/4 inch
- Gas line: 3/8 inch
At AirGreen, we always insist on compliant installation with quality insulation (often K-Flex type) to avoid heat loss and ensure system durability.
Dimensions and placement
- Outdoor dimensions: 42.25 x 33.63 x 18.38 inches
- Weight: 66 kg (145 lb)
These dimensions allow for wall or ground-mounted installation, depending on site constraints.
R-454B refrigerant: a transition to the future
This heat pump uses R-454B refrigerant, a more environmentally friendly alternative compared to older gases like R-410A.
Advantages:
- Reduced environmental impact
- Better compliance with future standards
- Improved energy performance
At AirGreen, we strongly recommend systems using modern refrigerants, particularly to ensure the longevity of the investment.
Real AirGreen installation case
Laval Project – Intergenerational Home
We installed this FORESTAIR 4-zone 36,000 BTU heat pump in an intergenerational home including:
- Ground floor
- Finished basement
- Two upstairs bedrooms
Challenges encountered:
- Balanced air distribution
- Management of piping lengths
- Optimization of unit positioning
Solution provided:
- Configuration into 4 distinct zones
- Installation with optimized lines to minimize losses
- Precise calibration of air flows
Result:
- Uniform comfort throughout the house
- Significant reduction in energy costs
- Client extremely satisfied with individual control
Common mistakes to avoid with multi-zone systems
-
Undersizing indoor units
→ Can lead to lack of comfort -
Poor zone planning
→ Thermal imbalance -
Installation without precise length calculations
→ Performance loss -
Choosing a non-specialized installer
→ Recurring problems
At AirGreen, we always conduct a complete building analysis before any HVAC installation to avoid these errors.
Why choose AirGreen for your HVAC installation?
- Recognized expertise in Montreal, Laval, Longueuil, and the South Shore
- Certified and experienced technicians
- Personalized approach for each project
- Transparent pricing with no surprises
- Fast and efficient after-sales service
We have installed hundreds of multi-zone systems and have a perfect command of the specificities of this type of equipment.
Conclusion: a complete, efficient, and durable solution
The FORESTAIR MZ R454B 36,000 BTU 4-zone wall-mounted heat pump represents an ideal solution for residences requiring precise room control, high energy efficiency, and reliable winter performance.
Whether for a project in Montreal, Laval, Longueuil, on the North Shore, or the South Shore, this system offers an excellent balance between performance, flexibility, and economy.
Take action with AirGreen
Are you considering a multi-zone HVAC installation or looking to replace your current system?
Contact AirGreen today to get a personalized quote, advice tailored to your property, and professional installation carried out according to the industry's best practices.
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 4 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.