LG: 3x3 Cassette-type Ceiling Concealed Duct | 36,000 BTU

A recessed HVAC solution for large spaces where comfort needs to remain discreet

The LG 3x3 Cassette Type Ceiling Unit | 36,000 BTU is designed for buildings where heating and air conditioning performance must seamlessly integrate with interior architecture. Unlike a visible wall-mounted unit, this cassette installs in the ceiling and diffuses air in multiple directions, making it a particularly attractive option for open-plan areas, offices, businesses, waiting rooms, condos with suspended ceilings, restaurants, clinics, and certain multi-unit spaces.

At AirGreen, we recommend this type of equipment when comfort needs to cover a large volume without monopolizing a wall, without creating an unpleasant air draft for occupants, and without detracting from the interior design. In Montreal, Laval, Longueuil, on the North Shore, the South Shore, and in Montérégie, we often encounter projects where a classic wall-mounted heat pump is not the best choice: large windows, walls occupied by storage, commercial ceilings, a central reception area, a space with constant circulation, or the need for more uniform diffusion.

This LG model precisely addresses this type of context. It combines an indoor unit KNSCB361A and an outdoor unit KUSXB361A, with a nominal cooling capacity of 36,000 BTU, operation with R-32 refrigerant, ENERGY STAR® certification, and a design adapted for cold climates. The LG KSSCB361A technical sheet indicates a cooling capacity of 14,400 to 42,000 BTU/h, a heating capacity of 16,000 to 42,200 BTU/h, a SEER2 of 22.0, an EER2 of 13.0, and an HSPF2 of 10.3; diagrams on pages 2 and 3 also detail the dimensions and mounting points of the indoor and outdoor units.

Why a 3x3 cassette changes the experience in a large room

A ceiling cassette is not just for hiding the indoor unit. Its primary advantage is air distribution. In an open-plan area, a wall-mounted unit can sometimes concentrate cooling or heating in a single zone, especially when the room is long, has many windows, or is divided by furniture. A four-way cassette installed in the right place, however, allows for more balanced air distribution.

In a commercial space on the South Shore, for example, a frequent need is to air condition a reception area without directing cold air directly onto the counter, customers, or employees. A well-positioned 3x3 cassette can reduce this problem, as the airflow is distributed in multiple directions. In an office in Laval or a professional space in Montreal, this approach also helps to limit common complaints: one person is too cold near the unit, while another area remains too hot.

The recessed format is also appreciated in projects where aesthetics matter. Suspended ceilings, conference rooms, retail stores, and healthcare spaces benefit from keeping walls clear. For property owners, this often facilitates future space planning, as the HVAC equipment does not dictate the placement of furniture, displays, or partitions.

Commented technical sheet for the LG KSSCB361A

These figures are important, but they never replace a building analysis. A 36,000 BTU cassette may be perfectly suited for a large open space, but oversized for a smaller room or poorly positioned in a highly compartmentalized area. At AirGreen, we always consider the area, ceiling height, solar orientation, insulation level, amount of glazing, actual room usage, and number of occupants before confirming a recommendation.

Heating in cold climates: what you need to understand

In the Montreal region, a heat pump must be seriously evaluated for winter heating. The LG KSSCB361A is indicated as a cold climate compatible model, with a heating operating range down to approximately -20 °C according to manufacturer data. The technical sheet also mentions maximum heating capacities of 38,000 BTU/h at 17°F, 35,000 BTU/h at 5°F, and 31,450 BTU/h at -4°F.

This means that the device maintains significant heating capacity when the temperature drops, but sizing must remain rigorous. In an old house in Montreal-East, in a business in Longueuil, or in a condominium on the North Shore, heat losses can vary greatly. Two premises of the same area may require very different capacities if one has large north-facing windows and the other a well-insulated low ceiling.

Our role is to avoid two common mistakes:

1. Installing too small, which forces the appliance to run for extended periods without achieving expected comfort on very cold days.
2. Installing too large, which can lead to short cycling, less stable dehumidification in summer, and uneven comfort.

The correct calculation is done on-site, not just from a product sheet.

What we check before recommending this LG cassette

Ceiling space and access for maintenance

A 3x3 cassette requires more precise coordination than a wall-mounted unit. Before recommending this model, we check the available ceiling space, structure, mechanical obstructions, light fixtures, sprinklers, existing ducts, access to the condensate drain, and possibilities for future service. The dimensional drawings in the LG brochure show that installation must adhere to precise suspension, opening, and clearance measurements; this step is essential to avoid an installation that is difficult to maintain.

In many commercial buildings in Montreal and on the South Shore, suspended ceilings already conceal electrical systems, ventilation ducts, plumbing pipes, or structural elements. An inspection before quotation helps avoid surprises: relocating a light fixture, adding an access hatch, adapting drainage, or choosing a more central location.

Condensate drainage

The model includes an internal condensate pump, a major advantage for ceiling installation. However, this does not mean that drainage can be improvised. The drain path must be clean, accessible, protected against back-slopes, and compliant with building regulations.

A common mistake is underestimating the amount of water produced in cooling mode, especially during humid July and August days in Montreal, Laval, and Longueuil. With a stated dehumidification of 7.8 pints per hour, reliable evacuation must be planned. During our installations, we pay particular attention to the following points:

• drain slope and routing;
• protection against obstructions;
• access for cleaning;
• insulation of sections exposed to condensation;
• checking pump operation before handover.

Poorly planned drainage can cause leaks, ceiling stains, and avoidable service calls.

Outdoor unit location

The outdoor unit KUSXB361A must be installed to ensure good airflow, safe service access, and a stable base. On the North Shore and South Shore, we often see installations where snow, ice, prevailing winds, or lack of clearance impair performance. A heat pump of this capacity must breathe properly.

Depending on the building, the unit can be installed on the ground, on a wall mount, or in a technical location, provided clearances, noise, piping, defrost drainage, and municipal regulations are respected. The datasheet indicates an outdoor sound level of approximately 52 to 54 dB(A) depending on the mode, which must be considered near windows, neighbors, patios, or narrow alleys.

Control options and Wi-Fi

Wi-Fi control is optional with this model. For an owner-occupier, this allows for more convenient schedule management. For a business, office, or small building, control options can become even more important: wall-mounted control, central controller, dry contacts, remote temperature sensor, or integration with certain management solutions.

At AirGreen, we clarify this point from the quotation stage. The right controller depends on the actual use of the premises. A training room, a business with fixed hours, and a shared office do not have the same needs. A poorly chosen control can make the appliance less pleasant to use, even if the mechanical installation is excellent.

R-32, leak detection and professional installation

R-32 refrigerant is part of the new generations used in various HVAC equipment. The LG KSSCB361A integrates an R-32 leak detection sensor, which adds a layer of safety to the system. That said, installation quality remains crucial: brazing, vacuuming, leak testing, line length, refrigerant charge, piping protection, and electrical compliance must be executed rigorously.

Our refrigeration technicians ensure that the system complies with manufacturer requirements and applicable Quebec regulations. For a 36,000 BTU unit, details matter: wire gauge, circuit breaker, minimum circuit ampacity, surge protection, communication between units, and quality of refrigerant connections.

LogisVert Subsidy: a point to validate before work begins

The AirGreen product sheet indicates a $2,976 LogisVert provincial subsidy, updated as of November 26, 2025. As financial aid criteria can change, we always validate eligibility when preparing the quote. Hydro-Québec specifies that heat pumps installed starting November 26, 2025, must be ENERGY STAR® certified to be eligible for financial assistance, and its search tool allows for estimating the amount using the model number or AHRI number.

It is also important to remember that the program operates with specific deadlines and documents. Hydro-Québec notably states that an application must be submitted within nine months of the equipment installation date, and that the official list of eligible models takes precedence in case of discrepancy with another tool or information.

Examples of situations where this model is particularly relevant

In an open-plan office in Laval, a 3x3 cassette can offer better comfort than a wall-mounted unit installed at the end of the room. Four-way diffusion helps reduce cold or hot spots, especially when workstations are distributed around a central space.

In a store in Longueuil, this model can free up walls for shelves, display cases, or signage. The indoor unit becomes less intrusive while providing effective air conditioning during busy periods.

In a multi-purpose room on the South Shore, the cassette can meet varied needs: morning meetings, evening activities, partial or full occupancy. With good control, the unit adapts better to changes in use.

In a condo or high-end residential space in Montreal, the ceiling-mounted format is often chosen to maintain a refined interior finish. However, the result depends on ceiling feasibility, drainage, and the piping path to the outside.

Recommended Maintenance to Maintain Performance

A cassette system requires regular HVAC maintenance. Filters, grilles, condensate pan, pump, drain, fan, and sensors must remain clean. In commercial spaces, maintenance often needs to be more frequent than in a residence, as dust, operating hours, and traffic are higher.

We generally recommend:

• periodic cleaning of filters;
• an inspection of the drain and pump before the warm season;
• a check of the heat exchangers;
• a check of heating operation before winter;
• an inspection of the outdoor support and clearances;
• a validation of supply and return temperatures;
• professional cleaning when the unit operates many hours per week.

Neglected maintenance can reduce efficiency, increase noise, impair dehumidification, and accelerate wear. For a cassette installed in a ceiling, ease of access must therefore be planned from the outset.

Why choose AirGreen for this LG product

Installing an LG 36,000 BTU cassette ceiling unit is not a standard operation. It requires coordinating architecture, electricity, drainage, refrigeration, structure, and the actual use of the space. At AirGreen, we take the time to propose a solution adapted to the building rather than a device chosen solely based on its nominal capacity.

Our teams operate in Montreal, Laval, Longueuil, on the North Shore, the South Shore, and in Montérégie for the installation, replacement, maintenance, and after-sales service of HVAC equipment. We provide a clear quote before work, check for subsidy possibilities, explain product limitations, and plan the installation so that the system remains accessible for future maintenance.

The LG: 3x3 Cassette-Type Ceiling Unit | 36,000 BTU is an excellent choice when the building requires a discreet, high-performance, well-distributed solution compatible with large volumes. To achieve the best result, installation must be carefully planned. Contact AirGreen for a quote, an analysis of your space, or a personalized recommendation for your cassette heat pump project in Montreal, Laval, Longueuil, on the North Shore, or the South Shore.