LG

LG MULTI F R32 4-Zone Heat Pump | 48,000 BTU Compressor

In stock
SKU: UMXB481A
48,000BTU/h · 4 heads
−16 °Cheats down to
$1,690LogisVert, indicative
ENERGY STAR®ENERGY STAR Most EfficientWi-Fi includedR-32Up to 8 heads
Talk to a technician · 514 316-2973
Outdoor unit UMXB481APossible indoor models KNUAK091A, KNUAK121A, NUAK181A, KNMAB071A, KNUAB091A, KNUAB121A, KNMAB151A, KNUAB181A, KNMAB241AAHRI 215402339· ENERGY STAR 3621273
In short

The LG Multi F R32 48 000 multi-zone heat pump heats and cools 4 rooms with a single outdoor unit. it delivers 33,800 BTU/h at −8 °C, heats down to −16 °C and qualifies for a $1,690 LogisVert grant. Installed by AirGreen in Montréal, Laval, Longueuil, the North Shore and the South Shore.

01 · The verdict in 10 seconds

4 rooms, one outdoor unit.

Compared with the 82 multi-zone systems of 48,000 BTU we sell. Every number on this page carries its source.

ENERGY STAR Most EfficientNEEP 389373AHRI 215402339LogisVert · October 1, 2026
+Only 55 dB(A) outdoorsRank 1 (tied) of 82. Class median: 64 dB(A).
+COP 2.17 at −15 °CRank 5 (tied) of 71. Class median: 2.00.
+EER2 12.8Rank 15 (tied) of 78. Class median: 12.0.
!Good to know: heats down to −16 °CRank 76 of 82; class median: −25 °C.
33,800BTU/h certified at −8 °C
−16 °Cstill heating
4 → 8heads, on the same unit
2.48COP at −8 °C
$1,690LogisVert, indicative
02 · The machine

The parts that make a multi-zone system.

Tap a part to learn more.

UMXB481A

Outdoor unit

One compressor for the whole house. It supplies up to 8 heads and modulates from 12,420 to 46,500 BTU/h depending on what the rooms call for (NEEP).

03 · How it works

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.

04 · My plan

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.

05 · The series

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.

Outdoor2 zones3 zones4 zones5 zones6 zones7 zones8 zones
18,000BTU
2
24,000BTU
23
30,000BTU
234
36,000BTU
234
48,000BTU
23Here5678

LG Multi F R32 48 000 · 4 zones

33,800 BTU/h
at −8 °C
$1,690
LogisVert

Up to 8 heads on this outdoor unit. Tap another box to see that size.

06 · Deep cold

At −15 °C, it still delivers 78 % 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.

+8.3 °C
12,420 → 59,000 BTU/h
-8 °C
13,950 → 46,500 BTU/h
-15 °C
12,555 → 39,600 BTU/h
Source: NEEP, minimum, rated and maximum ratings at 47, 17 and 5 °F.
07 · The bill

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.

08 · Efficiency

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.

SEER2 · seasonal cooling20.5
Scale 1 – 30Median: 21.3
Rank 54 (tied) of 78 in its class.
HSPF2 · seasonal heating9.5
Scale 1 – 15Median: 10
Rank 56 (tied) of 78 in its class.
EER2 · cooling in peak heat12.8
Scale 1 – 20Median: 12
Rank 15 (tied) of 78 in its class.
COP at −15 °C2.17
Scale 0 – 4Median: 2
Rank 5 (tied) of 71 in its class.
ENERGY STAR Most EfficientCold climate · ID 3621273 · ENERGY STAR database
09 · LogisVert grant

A grant you can calculate, not guess.

33,800 BTU/h÷ 1,000 ×$50=$1,690

The capacity at −8 °C comes from Hydro-Québec’s list of October 1, 2026. $50 per 1,000 BTU/h is the rate for ENERGY STAR heat pumps (guide v1.10).

Set for this system (AHRI 215402339). Another head combination (ducted, console) can change the AHRI number, and so the amount.
Cap: the grant never exceeds 100 % of the purchase and installation cost before taxes.
9 months after installation to apply; +5 % when two measures are in the same request.
All about LogisVert, with the simulator
10 · Report card

Where it ranks among same-size multi-zone systems.

Compared with the 82 multi-zone systems of 48,000 BTU we sell, using the LogisVert list figures. Weaknesses too, said plainly.

11 · Head-to-head

Against three other brands in its class.

Same rated size, other manufacturers. Pick the opponent.

12 · Multi-zone or wall units

One multi-zone or several wall units? Both sides, honestly.

This multi-zone4 wall units
On the wall1 outdoor unit4 outdoor units
Electrical1 dedicated circuitOne circuit per unit
CapacityShared between roomsReserved for each room
If the outdoor unit stopsEvery zone stopsOnly one room
ModesSame mode everywhereEach room chooses
LogisVert$1,690 for the systemDepends on each model

We compare both options on your floor plan during the estimate.

13 · Installation

What to know before installing a multi-zone system.

Dimensions, wiring and lines, drawn. Then our six steps.

The outdoor unit, dimensioned

54.34 in
UMXB481ADepth 15.66 in
37.41 in
Dimensions: product sheet (W × D × H).

One circuit for the whole house

Electrical panel
Load calculation before the quote
40 A max. breaker
MCA 34 A · 220 V
Outdoor unit
Head 1
Head 2
Head 3
Head 4
Our RBQ licence covers electrical work (subclass 16).
01Room-by-room visit and surveyWe measure each zone and note insulation and windows. The on-site estimate is free.
02Heads and line layoutOne pair of lines per head.
03Outdoor unit baseAbove the snow line, away from the neighbours’ bedroom windows.
04Exposed, finished linesLines under line covers, no work inside the walls.
05Dedicated circuit220 V, MCA 34 A, 40 A protection. The panel load calculation is done before the quote.
06Commissioning, zone by zoneEach head is tested and the controls set up. Then the LogisVert application within 9 months.
14 · Sound

Published sound levels, on one scale.

We use the outdoor figure to choose where the unit goes.

29
38
55
28
64
20 dB(A)3040506070
29 Reference head, lowest speed38 Reference head, highest speed28 Class indoor median55 Outdoor unit64 Class outdoor median
Values in dB(A). Indoor values are those of the sheet’s reference head; each head has its own, confirmed for the chosen model. Municipal noise by-laws vary by borough.
15 · What sets it apart

What is particular about this machine.

Only facts published by ENERGY STAR, NEEP or the manufacturer.

Most EfficientENERGY STARAmong the year’s most efficient according to ENERGY STAR.
46,500BTU/h peak at −8 °CIts maximum capacity certified by NEEP, above its rated value.
12,420BTU/h at low speedMinimum certified capacity (NEEP): it slows down instead of stopping when a single room calls.
−20 °CColdest certified pointNEEP still lists 34,500 BTU/h at a COP of 1.91 at −4 °F.
120 WBase pan heaterHeater in the outdoor unit’s base pan, against ice (NEEP).
675R-32 GWPGlobal warming potential of R-32, versus 2,088 for R-410A (ENERGY STAR).
16 · Specifications

Every number, and where it comes from.

Each line carries its source; a line with no published value is not shown.

Performance
Cooling capacity (size)48,000 BTUSheet
Certified cooling at 35 °C48,000 BTU/hNEEP
SEER2 (seasonal cooling efficiency)20.5AHRI
EER2 (instant cooling efficiency)12.8AHRI
HSPF2 (seasonal heating efficiency, region IV)9.5AHRI
HSPF2, region V (coldest)7.9NEEP
Heating
Capacity at +8.3 °C54,000 BTU/h · COP 3.5NEEP
Capacity at −8 °C33,800 BTU/h · COP 2.48NEEP
Capacity at −15 °C37,800 BTU/h · COP 2.17NEEP
Capacity at −20 °C (max.)34,500 BTU/h · COP 1.91NEEP
Modulation range12,420 – 46,500 BTU/hNEEP
Heats down to−16 °CSheet
Zones and heads
Zones on this product4 Zones (Quad Zone)Sheet
Maximum zones8 ZonesSheet
Possible indoor modelsKNUAK091A, KNUAK121A, NUAK181A, KNMAB071A, KNUAB091A, KNUAB121A, KNMAB151A, KNUAB181A, KNMAB241ASheet
Indoor dimensions (W × D × H)32.94 x 7.56 x 12.13 inSheet
Vertical louversAutoSheet
Horizontal louversAutoSheet
Airflow (reference head)459 CFMSheet
Indoor sound (reference head)29 – 38 dB(A)Sheet
Installation
Outdoor unit (W × D × H)37.41 x 15.66 x 54.34 inSheet
Outdoor sound55 dB(A)Sheet
Base pan heater120 WNEEP
Electrical
Voltage220 VSheet
MCA (minimum circuit ampacity)34 ASheet
MOP (maximum overcurrent protection)40 ASheet
RefrigerantR-32Sheet
Wi-FiIncludedSheet
Certifications and warranty
AHRI215402339AHRI
ENERGY STARYes · ID 3621273ENERGY STAR
ENERGY STAR Most EfficientYesENERGY STAR
LogisVert grant (indicative)$1,690LogisVert
Warranty (compressor · parts · labour)10 yrs · 10 yrs · 0 yrsSheet
AirGreen extended warrantyPossibleSheet
17 · Official brochures

The manufacturer’s documentation, as PDF.

18 · Description

Everything we have written about this system.

A multi-zone solution designed for the real comfort of homes and plexes in Greater Montreal

A multi-zone heat pump is not a simple comfort “gadget”: it is a structured way to solve a very common problem in residential buildings in the greater Montreal , Laval , Longueuil , North Shore and South Shore area: rooms that do not behave the same way, floors that overheat, basements that remain cool, closed offices that become uncomfortable as soon as the door is closed, and glazed areas that require a rapid response to weather variations.

The LG MULTI F R32 4-Zone Heat Pump | 48,000 BTU Compressor is designed precisely for this purpose: to offer a solid foundation (a high-performance outdoor unit) and the ability to manage multiple indoor zones, each with its own specific usage requirements. At AirGreen , we offer this type of configuration when the client wants room-by-room comfort without having to rewire the entire system, or when the building's architecture makes centralized solutions more cumbersome (or less practical) in the short term.

The characteristics we look for from the start (and why they matter)

Before even discussing brands or interior designs, a multi-zone system must be approached as a residential engineering project: sizing, planning, validation of constraints, and then assembly. Based on this, the “4 zones / 48,000 BTU” configuration is very interesting for several scenarios:

  • Rated cooling capacity: 48,000 BTU
    Useful for larger houses, large open areas, or buildings with multiple rooms that are demanding in summer.

  • Refrigerant: R-32
    A modern choice that also requires rigorous execution: clean connections, serious vacuuming, leak tests, well-protected routing.

  • Wi-Fi included
    Practical for monitoring performance, adjusting instructions and avoiding “extreme settings” that negatively impact comfort and fuel consumption.

  • AHRI: 215402339
    A useful reference point for compliance, comparison and certain administrative files.

  • ENERGY STAR®: Yes
    An important indicator when the goal is to reconcile comfort and efficiency.

  • Heating capacity advertised: down to -16°C
    A key point for Quebec: we want a heat pump that remains relevant during typical cold periods, while keeping expectations realistic according to the house, insulation and use of the zones.

  • Warranty: 10-10-0 (compressor – parts – labor)
    Important information for owners: the "paper" warranty is only worthwhile if the installation and commissioning are done methodically.


Understanding multi-zone technology: what it changes in everyday life

A well-designed multi-zone system transforms the comfort experience in three very concrete ways.

1) True temperature stability, especially in multi-story buildings

In much of Montreal 's housing stock (duplexes/triplexes, narrow houses, separate floors), hot and cold air do not naturally distribute themselves. A dedicated zone per level (or per use) reduces these differences, particularly:

  • between the basement and the ground floor,

  • between open area and closed rooms,

  • between glass-fronted rooms and more centrally located rooms.

2) Comfort adapted to the use of the rooms

A bedroom doesn't need to be treated like a living room. A home office doesn't have the same temperature tolerance as a laundry room. With multi-zone climate control, we stop "compensating" for one room by disrupting the others.

3) A smarter approach than multiplying outdoor units

In several Montreal neighborhoods and on certain streets in Laval and Longueuil , aesthetics, floor space, and the layout of balconies/staircases limit the installation of multiple condensers. A single multi-zone outdoor unit often provides a cleaner, more consistent, and easier-to-integrate result.


4 zones: how we define an effective configuration

The most common mistake is believing that "4 zones" automatically means "4 indoor units, one per room." In reality, a high-performing multi-zone system relies primarily on properly defining the zones.

At AirGreen , an area must be:

  • a space with a clear logic of use,

  • an area where air circulation is predictable,

  • an area that does not depend on a constantly open door,

  • an area where the chosen indoor unit can distribute effectively.

Typical examples of zoning that we regularly validate:

  • Zone 1: Main living area (open-plan living room/kitchen/dining room)

  • Zone 2: upstairs bedrooms

  • Zone 3: Finished basement (family room, gym, guest bedroom)

  • Zone 4: closed office / extension / glazed room (solarium, large windows, room above the garage)

This is not an automatic recipe: it's a starting point. Then, we adjust according to the orientation, insulation, lifestyle habits, and the reality of the building.


Installation: where multi-zone control is won (or lost)

A multi-zone heat pump can be excellent, but if the installation is improvised, problems always arise in the same place: noise, stability, seasonal performance, drainage, or "fussy" zones.

The routing of refrigerated lines: discipline before aesthetics

In a multi-zone system, the routing of lines is not just a visual issue: it is a mechanical and thermal issue.

At AirGreen, the goal is:

  • a direct and accessible route

  • robust protection (trunking, conduits, fasteners),

  • continuous insulation on exposed sections,

  • anti-vibration mounts in the right places,

  • a clean finish that respects the facade.

In Greater Montreal, freeze/thaw cycles and humidity can accelerate the wear of poorly installed insulation, cause poorly managed condensation, or make service difficult if everything has been “hidden” in the wrong place.

Differences in elevation: managing floors intelligently

Multi-level and multi-dwelling homes require a real strategy: where to place the outdoor unit, how to distribute the runs, and how to avoid unnecessary lengths.

In several projects in Longueuil and on the South Shore , we see buildings where the best "visual" location is rarely the best "technical" location. A good multi-zone project is one that includes:

  • easy access in winter,

  • sufficient clearance around the unit,

  • snow and ice management,

  • a reasonable proximity to the most demanding areas.

Electricity: a part of the project that is never simplified

A 48,000 BTU multi-zone heater is no small undertaking. Proper planning includes:

  • panel validation,

  • adequate protection

  • disconnect switch at the appropriate location,

  • clean and safe path

  • compliance and service logic.

This is often where intermittent problems (triggering, instability, defects) that waste time and money afterwards are avoided.


Choosing the interior units: the room dictates the decision

Your configuration allows for several compatible indoor unit options. For us, the mistake to avoid is simple: choosing solely based on BTU rating without considering air distribution and everyday use.

We are evaluating:

  • the shape of the room (long, square, open, compartmentalized),

  • the presence of corridors or blind spots,

  • ceiling height,

  • the position of the doors,

  • sensitivity to noise (bedrooms, offices),

  • aesthetics (available wall space, furniture, windows).

In a common scenario in Montreal , a client wanted to place a unit in a corner to "hide" it. On paper, this was possible. In practice, however, the air distribution would have been poor, and the unit would have overcompensated, increasing noise and energy consumption. We repositioned the unit, and the comfort level was immediately more stable.


Performance: what we clearly explain to owners

A well-designed multi-zone system provides comfort far above average, but we need to talk frankly about expectations, especially in Quebec.

Heating in winter: what makes the difference

A multi-zone heating system works very well when:

  • The zones are well distributed.

  • The instructions remain consistent.

  • The building has no major unaddressed losses.

  • The indoor units are adapted to the spaces.

What we often see: clients who want to "catch up" by 4 or 5 degrees in one area, while keeping other areas cooler. This kind of discrepancy creates less efficient cycles. Our approach: to explain a simple, stable, realistic, and optimized setpoint strategy.

Air conditioning: a 48,000 BTU unit is effective… if the air circulates.

In summer, comfort depends as much on capacity as on:

  • air circulation,

  • humidity management,

  • the position of the indoor units,

  • the logic of zones.

A common example on the North Shore : a large open-plan space with a central staircase. If the main area is poorly positioned, cool air rises, and the ground floor remains stuffy. With proper positioning and appropriate settings, the "escaping air" effect is greatly reduced.

Noise level: the final result depends on the installation

Even with advertised acceptable noise levels, the perceived noise level varies greatly:

  • of the support (slab, wall, structure),

  • vibrations transmitted to the lines

  • the distance from the windows,

  • the location in relation to corners and reflective surfaces,

  • wind and turbulence around the unit.

At AirGreen, we pay particular attention to the base, anti-vibration, and rigidity of the supports, because it is the details that transform the daily experience.


Common mistakes we avoid (and often correct)

Here are the scenarios we regularly encounter when multi-zone systems have been planned too quickly:

  • “Theoretical” zoning : one zone intended to serve two wings of the house. Result: one room too hot, the other too cold.

  • Poorly positioned indoor units : inefficient air distribution, more frequent cycling, feeling of discomfort.

  • Unnecessarily complex piping layout : more connection points, more risks, and complicated maintenance.

  • Poorly managed drainage : especially in installations where aesthetics take precedence over logic.

  • Extreme settings : excessively different instructions between zones, inadequate ventilation, and unrealistic expectations of recovery.

What distinguishes a reliable project: a clear design and serious commissioning, with explanations understandable to the owner.


Real-life scenarios from the greater Montreal area: why multi-zone is often the best answer

Family home in Laval: basement too cool and bedrooms too hot

In many typical houses, the upper floor heats up quickly, the basement remains cooler, and humidity builds up downstairs in the summer. A multi-zone system allows for:

  • an area dedicated to the basement,

  • an area dedicated to bedrooms,

  • a main area for the living space,

  • and an area for a more demanding room (office, extension, glass-enclosed room).

The result: fewer compromises, less “thermostat war”, and smoother management of seasonal transitions.

Duplex in Montreal: Comfort on each floor without renovating the entire building

In some duplexes/triples, installing a complete central system is possible, but sometimes disproportionate to the immediate need. Multi-zone systems offer a structured solution:

  • without a complete network of conduits,

  • with simpler external integration,

  • and interesting flexibility if the building evolves (renovations, new division, home office).

South Shore: large windows and rapid changes

Houses with large bay windows experience significant fluctuations in sunlight. A multi-zone approach prevents the entire house from being negatively affected by the glazed area, by allocating a dedicated capacity to each zone.


Why choose AirGreen for your LG MULTI F 4 zones

This product may be excellent, but satisfaction comes primarily from how it is integrated into the reality of the building. At AirGreen , our added value is evident in:

  • The design : zones, diffusion logic, line routing, location, future accessibility.

  • The quality of execution : supports, finish, insulation, drainage, mechanical stability.

  • Commissioning : testing, adjustments, simple and useful explanations, adaptation to lifestyle.

  • Follow-up : when a client tells us “a room is behaving differently”, we know where to look: zoning, settings, air diffusion, architectural constraints.

We operate in Montreal , Laval , Longueuil , North Shore and South Shore with a pragmatic approach: to create a clean, reliable, and pleasant installation.


Next Step

Are you considering an LG MULTI F R32 4-Zone Heat Pump | 48,000 BTU to better manage your comfort room by room? Contact AirGreen for an on-site estimate and a clear proposal: zoning, configuration, integration, and an installation plan tailored to your building in Montreal , Laval , Longueuil , North Shore , and South Shore .

19 · Questions

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: 33,800 BTU/h at −8 °C, 37,800 at −15 °C.

How many heads can I connect?

Up to 8 on this outdoor unit. This product is configured for 4 heads.

How much is the LogisVert grant?

$1,690 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, ID 3621273. It also meets the ENERGY STAR Most Efficient criteria, according to the ENERGY STAR database.

Down to what temperature does it heat?

Down to −16 °C.

Is it noisy?

Indoors, the reference head goes down to 29 dB(A). Outdoors, 55 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; labour is not included by the manufacturer. AirGreen extended warranty: possible.

AirGreen

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.

RBQ 5645-9605-01Ventilation 15.8, refrigeration 15.10, electrical 16
We handle the circuitOur licence covers the electrical work
LogisVert : $1,690AHRI 215402339 checked against the list of October 1, 2026
Beware of scamsHydro-Québec does no phone or door-to-door solicitation for LogisVert
Sources checked on October 1, 2026.NEEP, Cold Climate Air Source Heat Pump List, product 389373 (AHRI 215402339): capacities and COP, modulation, SEER2, EER2, HSPF2.ENERGY STAR certified heat pump database, ID 3621273.Hydro-Québec, LogisVert eligible heat pump list (owner, existing home), file of October 1, 2026; participation guide, version 1.10.Costs: Hydro-Québec Rate D, 11.142 ¢/kWh (second tier, since 1 April 2026). Amounts shown are estimates; only the responsible bodies confirm the grant awarded.