LG: LGRED 2x2 Cassette Type Ceiling Mounted | 18,000 BTU

An 18,000 BTU Ceiling Cassette Designed to Heat, Cool, and Free Up Wall Space

The LG 18,000 BTU 2X2 LGRED Ceiling Cassette is designed for spaces where a traditional wall-mounted unit is not suitable: suspended ceilings, open-plan areas, glass-fronted businesses, offices, conference rooms, condos with pre-occupied walls, professional premises, or residential zones where aesthetics are as important as performance. At AirGreen, we often recommend this format when a client is looking for a discreet, well-integrated HVAC solution capable of distributing air in multiple directions without monopolizing wall space.

This single-zone system combines the KNUDB181A indoor unit with the KUSXA181A outdoor unit. It is a 2 x 2 cassette heat pump using R-32 refrigerant, with a nominal cooling capacity of 18,000 BTU and a nominal heating capacity stated at 20,000 BTU according to the manufacturer's technical data. The LG technical sheet also indicates a modulating cooling capacity of 7,200 to 23,000 BTU/h and a modulating heating capacity of 6,500 to 24,000 BTU/h, which allows the system to adjust its operation according to the actual load of the room rather than operating purely in on-off mode.

For clients in Montreal, Laval, Longueuil, the North Shore, and the South Shore, this cassette becomes particularly relevant in buildings where direct drafts are to be avoided, a neat appearance is desired, and a more uniform distribution is needed than with some wall-mounted configurations. In several commercial projects in Boucherville, Saint-Lambert, Repentigny, or Terrebonne, we often see the same constraint: the room has large windows, few free walls, an accessible suspended ceiling, and a need for stable comfort during opening hours. In this context, an HVAC installation with a recessed cassette provides a very concrete solution.

Why the 2X2 Cassette Format Changes the Room Experience

A wall-mounted unit typically projects air from only one side of the room. The LG cassette, however, diffuses air on four sides, directly from the ceiling. This approach is useful in open-plan areas, waiting rooms, small businesses, executive offices, studios, treatment rooms, residential living rooms with suspended ceilings, and some finished basements.

The desired result is simple: fewer cold spots in summer, fewer cooler corners in winter, and a better feeling of stability in the occupied zone. The KNUDB181A system integrates a turbo-type fan and an airflow reaching up to 459 CFM at high speed, with intermediate ventilation levels of 424 CFM and 388 CFM. These values are important because a poorly chosen or positioned cassette can create a beautiful installation on paper, but uneven comfort in reality.

During our technical visits, we don't just measure the area. We also observe:

• the orientation of the building and sun exposure;
• the usual number of occupants;
• the ceiling height;
• the presence of frequent exterior doors;
• shop windows, curtain walls, or full-height windows;
• internal heat sources, such as computers, lighting, light kitchen appliances, or commercial equipment;
• the type of suspended ceiling and future access for HVAC maintenance.

This step avoids the common mistake of selecting a heat pump solely based on an approximate square footage.

Relevant Performance for Quebec's Climate

The LGRED 18,000 BTU model is designed to operate in heating down to -25 °C, which corresponds to the range indicated for the outdoor unit in heating mode. This is a crucial element for homeowners in Montreal, Laval, Longueuil, in Montérégie, on the South Shore, and on the North Shore, where periods of intense cold must be considered before purchasing a heat pump.

Key data points to remember:

• Nominal Cooling Capacity: 18,000 BTU/h
• Modulating Cooling Capacity: 7,200 to 23,000 BTU/h
• Nominal Heating Capacity: 20,000 BTU/h
• Modulating Heating Capacity: 6,500 to 24,000 BTU/h
• Heating Capacity at 17 °F: 13,600 BTU/h at nominal low temperature capacity
• Maximum Heating Capacity at 5 °F: 20,000 BTU/h
• Maximum Heating Capacity at -13 °F: 15,500 BTU/h
• SEER2: 20.5
• HSPF2: 9.5
• EER2 at 95 °F: 13.20
• COP at 47 °F: 3.37
• ENERGY STAR®: Yes
• ENERGY STAR® Cold Climate: Yes
• AHRI: 214825952
• ENERGY STAR ID: 3544254

On our product sheet, the indicated LogisVert provincial subsidy is $1,632, with an update mentioned for November 26, 2025. As subsidy programs can vary depending on the type of residence, address, system eligibility, and current regulations, we always validate the applicable conditions before finalizing a quote.

R-32, Efficiency, and Environmental Responsibility

The R-32 refrigerant is now used in several recent HVAC systems. It has an ozone depletion potential of 0 and a global warming potential of 675, according to the manufacturer's technical data. For a client, this does not replace performance, durability, and comfort criteria, but it is a factor to consider when comparing a new generation of heat pumps to older systems.

R-32, however, requires rigorous installation. It is classified as mildly flammable, which necessitates appropriate work methods, adapted tools, and a complete verification of the refrigeration circuit's airtightness. At AirGreen, our refrigeration technicians take R-32's specificities into account from the planning stage: piping dimensions, equivalent length, additional charge, clearances, commissioning, and safety instructions.

Recessed Installation: What Our Technicians Check Before Confirming the Project

The indoor cassette measures 22 7/16 x 22 7/16 x 10 3/32 in, with a required grille panel PT-QAGW0 measuring 24 13/32 x 24 13/32 in. This 2x2 dimension is well-suited for standard suspended ceilings, but the installation must be precisely planned. A cassette is not simply placed in a ceiling tile: it must be securely suspended, connected to the drain, connected to the refrigeration lines, electrically powered, and positioned to allow service access.

We particularly validate:

• the structural integrity above the ceiling;
• the available space for the indoor unit's body;
• the possibility of adhering to required clearances;
• the routing of refrigerant lines to the outside;
• the path of the condensate drain;
• the slope or management of condensate lift;
• access to the washable filter;
• the perceived noise level in the room depending on usage;
• the location of the outdoor unit to avoid snow, ice, prevailing winds, and air recirculation.

The indoor unit includes an integrated condensate pump with a maximum lift capacity of 27 9/16 in from the bottom surface of the unit. This is an advantage in many buildings with suspended ceilings, but it is not a permit to install the drain without a strategy. Poor drainage can lead to shutdowns, odors, water marks on the ceiling, and avoidable service calls.

Sound Level: Discreet, but Not to Be Overlooked

The indoor sound pressure level is indicated at 41 / 39 / 36 dB(A) at high, medium, and low speeds, for both cooling and heating. For an office, reception area, or treatment room, these values are important. However, it must be remembered that the perceived level also depends on the room: glass surfaces, acoustic ceiling, hard flooring, furniture, ceiling height, and the exact location of the cassette.

The KUSXA181A outdoor unit has a sound level of 51 dB(A) in cooling and 52 dB(A) in heating according to the manufacturer's test conditions. In residential areas of Montreal, in condominiums in Laval, or near property lines on the South Shore, the location of the outdoor unit must be carefully considered. We avoid locations that direct noise towards a bedroom, a neighboring yard, or a narrow corridor where sound could reflect.

Piping, Charge, and Limits: The Details That Make the Difference

For this 18,000 BTU system, the indicated piping dimensions are:

• Liquid line: 1/4 in connection, 3/8 in piping
• Vapor line: 1/2 in connection, 5/8 in piping
• Minimum equivalent length: 16.4 ft
• Maximum equivalent length: 164 ft
• Length without added refrigerant: 24.6 ft
• Additional charge: 0.38 oz/ft beyond standard length
• Maximum elevation difference: 98.4 ft

These figures are not just catalog information. They directly influence the actual capacity, efficiency, reliability, and compressor behavior. Piping that is too long, too short, incorrectly sized, crushed, poorly insulated, or installed with unnecessary bends can reduce performance and complicate commissioning.

In a typical case encountered during commercial renovation in Longueuil, the client wanted to install the cassette in the center of a space, but the outdoor unit had to be at the back of the building. The initial route proposed by another party involved many detours in the ceiling to bypass beams and plumbing. Our team revised the route, reduced changes of direction, maintained ceiling access, and calculated the correct additional charge. The client did not see the difference in the final appearance, but it manifested in stable operation and ease of maintenance.

Controls, Wi-Fi, and Daily Use

The system comes with a compatible wireless control. Wi-Fi is optionally available with the LG PWFMDD200 module, allowing integration with the LG ThinQ app when the installation and network are compatible. For some residential clients, mobile control is mainly used to adjust the temperature before returning home. For commercial premises, it can help limit forgotten settings after closing or prepare comfort before opening.

However, we recommend not basing the entire system choice on Wi-Fi. The primary criteria remain sizing, location, air distribution, sound level, installation quality, and accessibility for maintenance.

Warranty and Peace of Mind

The AirGreen sheet indicates a 10-year warranty on the compressor, 10 years on parts, and 0 years on labor, with a possible extended warranty. When quoting, we clearly explain what is covered by the manufacturer, what depends on the installation, and what additional options can be considered.

This transparency is important. A cassette heat pump is a serious investment, especially in a business or condo where ceiling access and finishing work must be coordinated. At AirGreen, we prioritize a clear final offer before work begins, including essential elements: equipment, installation, required accessories, specific constraints, options, warranty, applicable subsidies, and payment terms.

What the AirGreen installation offers beyond the spec sheet

A solution adapted to real buildings in Montreal, Laval, Longueuil, North Shore, and South Shore

Spec sheets provide numbers. The field adds constraints: ceilings that are not perfectly straight, old structures, co-ownership rules, narrow backyards, outdoor locations exposed to wind, commercial premises with tight schedules, and sometimes limited access for work.

At AirGreen, we install HVAC systems in residential, commercial, and multi-unit buildings. The LG ceiling cassette 2X2 LGRED 18,000 BTU is particularly suitable when the owner wants a clean finish and central air distribution without installing full ducts. In a professional office in Montreal East, for example, a ceiling cassette can avoid sacrificing a wall already occupied by cabinets or glass. In a service area in Boucherville, it can provide regular air conditioning in a reception area where doors open frequently. In a condo in Laval, it can reduce the visual impact compared to a more apparent wall unit.

Mistakes to avoid with a ceiling cassette

A successful installation begins with the mistakes we refuse to make.

1. Installing the cassette too close to an obstacle
A dropped ceiling, a beam, a suspended light fixture, or a high partition can hinder air diffusion. A four-way cassette needs to breathe freely.

2. Neglecting the condensate drain
Even with an integrated pump, a safe path must be planned. The drain must be accessible, insulated if necessary, and connected according to best practices.

3. Forgetting filter access
The washable filter must be easily removable. An installation that is too tight or placed above fixed furniture complicates HVAC maintenance.

4. Assuming 18,000 BTU is suitable for any open space
Two rooms of the same area can have very different needs. A south-facing window in Longueuil does not behave like an insulated basement on the North Shore.

5. Placing the outdoor unit without considering snow
In Quebec, accumulated snow, defrost ice, and prevailing winds directly influence heating performance. A base that is too low or a location that is too enclosed can cause recurring problems.

6. Confusing Wi-Fi compatibility with Wi-Fi included
For this model, Wi-Fi is an option. We clearly indicate this to avoid any confusion at the time of installation.

A good choice for what types of projects?

This model can be particularly interesting for:

• a local business in Montreal with a suspended ceiling;
• a professional office in Laval;
• a conference room or reception area in Longueuil;
• a care facility, salon, or studio in Montérégie;
• an open-plan residential area with wall constraints;
• a finished basement with an accessible ceiling;
• a space where the appearance of the indoor unit must remain discreet;
• a project where heating and cooling are desired without a full duct network.

It is not automatically the best choice for every building. In some cases, a wall-mounted unit, a console, a ducted unit, or a multi-zone system may be more appropriate. Our role is to recommend the option that truly serves comfort, budget, efficiency, and durability.

Our work method

A typical AirGreen installation for this type of cassette follows a structured approach:

1. Assessment of the area to be served: area, insulation, fenestration, orientation, use, schedules, and constraints.
2. Ceiling validation: structure, clearances, positioning, panel, filter access, and drain.
3. Choice of outdoor location: noise, snow, clearances, exposure, service access, and piping length.
4. Electrical coordination: 208-230 V supply, appropriate circuit, protections, and compliance.
5. Refrigeration installation: piping, insulation, brazing or connection as required, evacuation, leak test, and charge.
6. Commissioning: verification of modes, temperatures, drainage, remote control, airflows, noise, and operating instructions.
7. Maintenance tips: filter cleaning, seasonal best practices, and signs to watch for.

We are also covered by a 5M$ civil liability insurance and hold RBQ license # 5645-9605-01, two important elements for work in residences, businesses, and multi-unit buildings.

Recommended maintenance after installation

To maintain the performance of the LG ceiling cassette 2X2 LGRED 18,000 BTU, we recommend regular maintenance. The washable filter must be cleaned according to actual use. In a commercial environment with heavy traffic, more frequent cleaning may be necessary. In a normal residential environment, the interval can be longer, but it should not be ignored.

Professional maintenance also allows checking:

• the condition of the drain and condensate pump;
• the cleanliness of the indoor coil;
• operating pressure and temperatures;
• the condition of the outdoor unit;
• the absence of obstruction by leaves, snow, or dust;
• signs of unusual vibration or noise;
• heating performance before winter.

A clean system consumes less, heats better, cools more efficiently, and reduces the risk of service calls during peak demand periods.

A discreet product, but an installation that requires expertise

The great advantage of a cassette is its discretion. Once installed, it blends into the ceiling and leaves the walls free. But this discretion should not overshadow the technical complexity of the project. The cassette must be installed with precision, the outdoor unit must be well located, the piping must respect the limits, drainage must be reliable, and the system must be commissioned correctly.

At AirGreen, we bring this rigor to every installation of heat pumps, air conditioning, heating, and HVAC systems in Greater Montreal. For a client, this means fewer unforeseen events, a cleaner finish, a clear explanation of options, and a system installed to function correctly in the real conditions of Quebec.

Request an AirGreen quote

For an installation of an LG 2X2 LGRED 18,000 BTU cassette ceiling unit in Montreal, Laval, Longueuil, on the North Shore or the South Shore, contact AirGreen. We can evaluate your space, confirm eligibility for available subsidies, check installation constraints, and propose a clear, complete, and adapted solution.

Call us at 514-316-2973 or write to sales@airgreen.ca to get a quote, schedule a technical visit, or compare this model with other HVAC options.