LG Multi F MAX LGRED R32 Heat Pump | 2 Zones + 42000 BTU | Montérégie
The LG Multi F Max LGRED R32 42 000 multi-zone heat pump heats and cools 2 rooms with a single outdoor unit. it delivers 31,600 BTU/h at −8 °C, heats down to −25 °C and qualifies for a $3,792 LogisVert grant. Installed by AirGreen in Montréal, Laval, Longueuil, the North Shore and the South Shore.
2 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 6 heads and modulates from 12,420 to 53,200 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 104 % 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 multi-zone solution designed for demanding buildings in the Montérégie region
In the Montérégie region , many homeowners, building managers, and contractors are now looking for HVAC systems that offer true flexibility , stable winter heating , and precise control of multiple zones without requiring numerous outdoor units. The LG Multi F MAX LGRED R32 – 2-zone, 42,000 BTU heat pump perfectly addresses this real-world need that we encounter daily at AirGreen.
This system is not designed for standard needs. It is intended for large houses , plexes , multi-unit residential buildings , offices and certain commercial spaces where independent zone control is essential, both for comfort and energy optimization.
At AirGreen, we install this type of configuration in projects where a simple wall-mounted heat pump would be insufficient, but where a complete central system would be neither relevant nor cost-effective.
Multi F MAX Architecture: Understanding what you are actually installing
The LG Multi F MAX LGRED R32 is based on a multi-zone architecture with variable refrigerant flow , allowing up to 6 indoor units to be connected to a single outdoor unit, even though this product sheet is configured here for 2 active zones .
KUMXA421A outdoor unit: the heart of the system
The KUMXA421A outdoor unit offers a nominal cooling capacity of 42,000 BTU and an operating range suitable for cold climates. It is designed to operate in heating mode down to -25°C , with remarkable low-temperature stability.
This unit uses:
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A variable speed scroll compressor
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R-32 refrigerant , more efficient and with a reduced global warming potential
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An intelligent defrosting system optimized for Quebec winters
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Precise electronic management (EEV) to adjust the flow rate according to actual demand
In practice, this means fewer on/off cycles, better controlled consumption and a more stable indoor temperature.
Heating and air conditioning performance in a climate like Montérégie
Winter heating: a non-negotiable criterion
In the Montérégie region , heating is not a secondary consideration. The LGRED Multi F MAX is designed to maintain high capacity even when temperatures drop sharply.
In harsh winter conditions, we observe:
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A maximum heating capacity of around 48,000 to 54,500 BTU depending on the conditions
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Performance is maintained down to -20°C and even down to -25°C depending on the configuration.
In practice, this translates to:
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Less need for supplemental heating
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Improved comfort consistency in remote areas
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A reduction in temperature differences between rooms
Controlled summer air conditioning
With 42,000 BTU of cooling capacity , this system can efficiently serve large areas while modulating its power according to the actual needs of each zone. In summer, this allows for:
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A faster temperature rise
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Better humidity management
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A reduction in unnecessary overconsumption when certain areas do not require cooling
Flexibility of indoor units: a tangible advantage
One of the major advantages of this LG heat pump is its compatibility with a wide range of indoor units :
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Wall-mounted (9,000 to 24,000 BTU)
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Consoles
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Ducted
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Cassettes (depending on the project)
This flexibility allows AirGreen to adapt each project to the architectural reality of the building , without aesthetic or functional compromise.
In several projects in the Montérégie region , we have, for example:
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Installed a wall unit in a main living area
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Combined with a discreet ducted unit for bedrooms
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Maintained a single outdoor unit to limit the external footprint
Technical constraints controlled by AirGreen
A Multi F MAX system cannot be improvised. Pipe lengths, elevation differences, and refrigerant distribution must be calculated precisely.
Key data to respect during installation
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Total piping length up to 475 feet
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Maximum length between outdoor unit and indoor units: approximately 98 feet
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Maximum height difference between indoor units: approximately 49 feet
At AirGreen, each project is subject to:
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From a detailed technical survey
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From a precise calculation of equivalent lengths
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Strategic positioning of distribution units
It is this rigor that guarantees the long-term reliability of the system.
Noise, comfort and residential integration
Despite its power, the outdoor unit maintains a controlled noise level , typically around 54 to 56 dB(A) depending on the operating mode. In practice, this allows for easy installation:
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In a residential backyard
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Near outdoor living areas
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On multi-unit residential buildings without excessive nuisance
Inside, the compatible units descend to very discreet levels, which is particularly appreciated in bedrooms and offices.
Electrical safety and compliance
For this model:
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Voltage: 208-230V
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MCA: approximately 32.5 A
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MOP: 40 A
AirGreen systematically ensures that:
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The electrical panel is compliant
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The protective measures are adequate.
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The installation complies with the Quebec Electrical Code
AirGreen real-life case study in Montérégie
In a recent project in Boucherville , a renovated duplex had very different heating and cooling needs between the ground floor and the upper floor. We installed an LG Multi F MAX LGRED with two separate indoor units, allowing for:
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Independent temperature control
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A significant reduction in comfort-related complaints
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A measured decrease in consumption compared to two independent systems
This type of feedback is common on this model when the sizing is done correctly.
Why entrust this system to AirGreen?
Installing an LG Multi F MAX heat pump is more than just installing equipment. It's a complete HVAC project that requires:
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Genuine multi-zone expertise
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A precise reading of the technical constraints
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Field experience in Montreal, Laval, Longueuil, North Shore, South Shore and Montérégie
At AirGreen , we combine:
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Certified refrigeration technicians
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$5 million liability insurance
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A transparent approach, with no surprises at the end of the project
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In-depth knowledge of programs like LogisVert
A sustainable, scalable and consistent solution
The LG Multi F MAX LGRED R32 heat pump – 2 zones, 42,000 BTU – is a logical choice for those who want a system:
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Powerful without being oversized
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Flexible in its configuration
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Adapted to the climatic realities of Quebec
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Evolving if new areas are added later
Take action with AirGreen
Are you considering a multi-zone HVAC installation in Montérégie , Montreal , Laval , Longueuil , on the North Shore or the South Shore ? Our experts can analyze your building, validate the sizing and offer you a perfectly adapted solution.
Contact AirGreen today for a detailed estimate, a technical visit or specific advice on the LG Multi F MAX LGRED R32 heat pump.
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: 31,600 BTU/h at −8 °C, 44,000 at −15 °C.
How many heads can I connect?
Up to 6 on this outdoor unit. This product is configured for 2 heads.
How much is the LogisVert grant?
$3,792 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 3621281. 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 29 dB(A). Outdoors, 56 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.