SENVILLE LETO Mini-Split | 36000 BTU | Montréal, Laval, South Shore

36,000 BTU in a single wall-mounted unit: a solution that requires as much attention to sizing as to installation

The 36,000 BTU SENVILLE LETO is not a mini-split intended for a small bedroom or enclosed office. With a rated capacity of 36,000 BTU/h, an indoor unit nearly 50 inches wide, a 208/230 V power supply, and 3/8 in – 5/8 in refrigerant piping, this is a wall-mounted heat pump designed for much larger spaces.

At AirGreen, this type of capacity makes the most sense in a large open-concept area, business, workshop, large basement, loft, or residential space with a high heating or cooling load. In Greater Montreal, however, the question is never simply whether 36,000 BTU is “enough.” We must determine whether this capacity can be distributed properly throughout the building and whether the heating performance meets the homeowner’s expectations during Quebec winters.

The configuration offered on our site uses the SENL-36CD-OL outdoor unit and the SENL-36CD-ILL indoor unit, associated with AHRI 215735293. Senville documentation identifies the technical family under model SENL-36CD-L and confirms that it is a 36,000 BTU LETO mini-split air conditioner and heat pump.

This precision is useful when a homeowner compares several documents: the suffixes may distinguish the indoor and outdoor components, while the general documentation groups the system under a series designation.

The essential features of the 36,000 BTU SENVILLE LETO

The official technical table on page 4 of the brochure provides a much more precise overview of the unit:

• Rated cooling capacity: 36,000 BTU/h
• Cooling range: 2,900 to 36,200 BTU/h
• Rated heating capacity: 36,000 BTU/h
• Heating range: 3,600 to 36,600 BTU/h
• SEER2: 18
• EER2: 9
• HSPF2 Region 4: 8.5
• HSPF2 Region 5: 6.8
• COP listed: 2.82
• Power supply: 208/230 V, single-phase, 60 Hz
• MCA: 33 A
• Maximum protection: 35 A
• refrigerant: R-454B
• refrigerant precharge: 25 feet
• connection wiring: 14/4 AWG

These values come directly from the Senville technical table.

The AirGreen listing currently displays certain efficiency values in a concatenated format, including “118.030” for SEER2 and “19.020” for EER2. To avoid any ambiguity, we use the figures clearly presented in the official technical documentation here: 18 SEER2 and 9 EER2.

A surprisingly wide modulation range for a 36,000 BTU unit

Maximum capacity naturally draws attention, but minimum capacity is almost as interesting.

In cooling mode, the compressor can go down to approximately 2,900 BTU/h, according to the documentation. In heating mode, the published range starts at approximately 3,600 BTU/h.

This feature is important.

A heat pump with DC Inverter technology does not operate constantly at 36,000 BTU. It adjusts its output according to demand. The manufacturer also explains that its Inverter system modulates its operation in real time to maintain the desired temperature without constantly using its maximum capacity.

For a large room that requires substantial cooling during a July day but very little during a cool evening, this modulation significantly improves the unit’s operation.

It also helps avoid an unnecessary succession of starts and stops when the load decreases.

1,250 to 1,800 sq. ft.: why this recommendation should be interpreted with caution

Senville presents the LETO 36,000 BTU as suitable for spaces of approximately 1,250 to 1,800 sq. ft., particularly large rooms and living areas.

At AirGreen, we use this figure only as an initial guideline.

A wall-mounted mini-split does not have a duct network. Even with a capacity of 36,000 BTU, it cannot efficiently move its air through multiple walls, hallways, and closed doors.

Let’s consider two 1,500-square-foot properties.

The first is a loft with the kitchen, living room, and dining room combined into a single space. A high-capacity wall-mounted unit may have access to much of the space.

The second is a bungalow with four bedrooms, several hallways, and doors that are regularly closed. Even if the total square footage is identical, a single 36,000 BTU wall-mounted heat pump does not automatically distribute its 36,000 BTU to each room.

This is a situation we regularly explain during our assessments of wall-mounted heat pumps in Montreal, Laval, Longueuil, and the South Shore: heating capacity and air distribution are two different problems.

A nearly 50-inch-wide unit: its location must be decided before installation

The indoor unit measures:

49.57 in wide × 11.10 in deep × 14.25 in high

and weighs approximately 40.34 lb.

The outdoor unit measures:

37.24 in × 16.14 in × 31.89 in

with a weight of 142.86 lb.

These dimensions significantly change the installation planning compared with a 9,000 or 12,000 BTU mini-split.

A wall that seems large enough in a photograph can become much more restrictive when we need to plan:

• the actual width of the evaporator;
• the required clearances;
• the piping outlet;
• access for maintenance;
• the direction of the airflow;
• the aesthetics of the installation.

The outdoor unit's weight is also significant. At nearly 143 lb, the choice of a wall bracket or ground stand must be suitable for this equipment category.

A verified buyer quoted in the Senville brochure specifically points out that the unit is bulky, requires considerable space, and that the lines are relatively difficult to bend, while also noting that the unit performs as expected.

This is practical feedback that reflects an installation reality: a 36,000 BTU heat pump is not handled like a small wall-mounted unit.

3/8-inch – 5/8-inch piping: a major detail on the job site

The AirGreen configuration indicates 3/8-inch – 5/8-inch piping.

With a 5/8-inch gas line, bends, changes in direction, and tight passages require more planning. This becomes especially important in Montreal plexes, South Shore townhouses, condominiums, or projects where the refrigerant line must go around a door, window, or balcony.

The documentation also indicates that the unit is precharged for 25 feet of piping. For a 50-foot set, Senville specifies that an additional R-454B charge must be added on site by the installer.

We therefore need to know the actual line-set length before commissioning.

This is not merely a matter of the amount of copper. A professional installation requires proper work on the connections, circuit preparation, leak testing, and commissioning according to the manufacturer's specifications.

R-454B: the refrigerant generation used by this LETO

The SENVILLE LETO 36,000 BTU uses R-454B. The technical table also confirms a factory charge intended for 25 feet.

This information must be taken into consideration during installation and service, particularly because the equipment, work procedures, and handling of the refrigeration circuit must correspond to the refrigerant used by the system.

For a customer, the key point is simpler: this is not an older model that uses a previous-generation refrigerant. The technician must therefore use the appropriate methods and tools.

33 A MCA and 35 A maximum protection: check the electrical system before the project begins

A 36,000 BTU mini-split requires a significantly larger electrical circuit than a lower-capacity wall-mounted unit.

For the LETO:

MCA: 33 A
Maximum protection: 35 A

The documentation and the AirGreen listing agree on these values.

We therefore check the available power supply before installation.

A common mistake is to order a heat pump assuming that the circuit from an older, smaller unit can be reused directly. If the old unit was 12,000 or 18,000 BTU, the existing circuit may not meet the new system’s electrical requirements.

This preliminary check prevents us from arriving on-site with a heat pump ready to be installed when the electrical circuit needs to be modified.

882.9 CFM in Turbo: why airflow matters on a unit this large

The manufacturer’s table provides four indoor airflow rates:

882.9 CFM in Turbo
732.8 CFM at high speed
518.0 CFM at medium speed
400.2 CFM at low speed

The associated sound pressure levels are:

56.5 dB(A) in Turbo
50.5 dB(A) at high speed
44.5 dB(A) at medium speed
34 dB(A) at low speed.

The AirGreen listing currently displays a CFM field as “1883,” which does not match the indoor airflow detailed in the brochure. For a technical comparison, we therefore use the four airflow rates published in the official table.

An airflow of nearly 883 CFM also explains why positioning the indoor unit is so important. At high speed, the air movement is considerable.

Installing such a unit too close to a living area or directly facing an occupied zone can create a draft-like sensation. The goal is to use the airflow to distribute the temperature throughout the room, not to direct the flow constantly toward occupants.

34 dB(A) minimum, but 56.5 dB(A) in Turbo

Senville describes the system as capable of operating at up to 34 dB(A) on the quietest indoor setting.

This figure is useful, but it should be presented alongside the full sound range.

At full fan speed, the unit reaches 56.5 dB(A).

For a 36,000 BTU heat pump intended for a large open area, this behavior is consistent with the required airflow. A room that requires substantial capacity needs a great deal of air to be moved.

The outdoor unit is rated at 61.4 dB(A) with a maximum outdoor airflow of 2,235.3 CFM.

In a dense environment in Montreal or a narrow yard in Longueuil, we therefore take into account the condenser’s location, reflective surfaces, nearby windows, and potential vibrations.

A dehumidification capacity of 4.9 L/h

The documentation indicates moisture removal of up to 4.9 liters per hour.

For large open areas, this feature can make a significant contribution to comfort during hot and humid periods.

The temperature shown on the thermostat does not tell the whole story. A space at 23 °C with high indoor humidity can remain uncomfortable.

The compressor’s modulation capability is useful here: when properly sized, the system can maintain more stable operation and help control humidity rather than operating only in very short cycles.

Heating in Quebec: what the LETO 36,000 BTU can actually deliver

Heating advertised down to -15 °C

Senville’s official documentation clearly presents this model as a unit offering heating down to -15 °C.

This information should be emphasized because the LETO 36,000 BTU is not presented as an ENERGY STAR Cold Climate heat pump.

The AirGreen specifications confirm:

ENERGY STAR: No
ENERGY STAR Cold Climate: No

This does not mean that the unit cannot heat efficiently during a large portion of the winter. Rather, it means that it should not be compared directly with a model specifically designed to maintain high capacity during extreme temperatures.

AirGreen’s published low-temperature capacities

Our product page provides several particularly useful performance points:

24,600 BTU/h at -8 °C
21,400 BTU/h at -15 °C
11,200 BTU/h at -25 °C

These figures clearly show the decrease in capacity as the outdoor temperature drops.

At -15 °C, for example, the available 21,400 BTU/h represents approximately 59% of the 36,000 BTU rated capacity.

At -25 °C, the indicated 11,200 BTU/h represents approximately 31% of the rated capacity.

This is probably the most important information to understand before using this system as the primary heating source.

A homeowner may see “36,000 BTU” and assume that this capacity is available regardless of the outdoor temperature. In practice, a heat pump’s capacity changes with conditions.

Why a supplementary heating system may still be necessary

In a large commercial room or residential space that genuinely requires 30,000 to 36,000 BTUs on the coldest days, a capacity of 21,400 BTU at -15 °C may not be sufficient on its own.

The existing electric heating can then supplement the heat pump.

This combination can make perfect sense if the LETO meets a large portion of the heating needs during the fall, spring, and milder winter periods, while a supplementary source comes into play during the coldest temperatures.

At AirGreen, we prefer to explain this reality before installation rather than promise that a 36,000 BTU unit will automatically replace all existing heating systems.

Is the 36,000 BTU LETO suitable for Montreal, Laval, and the South Shore?

Yes, for the right project.

We would consider it especially for a large open area, a business, a workshop, a substantial basement, or an area where 36,000 BTU cooling capacity is the priority.

We would be more cautious if the owner is primarily looking for:

• primary heating at very low temperatures;
• an ENERGY STAR Cold Climate certification;
• eligibility for a subsidy linked to this certification;
• high capacity maintained during extreme cold spells.

The AirGreen product sheet currently shows no LogisVert subsidy amount for this combination and indicates that the unit is not ENERGY STAR certified. We therefore recommend not including a subsidy in the net-price calculation until eligibility applicable at the time of purchase has been confirmed.

WiFi, Alexa, and remote control

The AirGreen product sheet indicates that WiFi is included.

The Senville documentation also confirms Alexa compatibility and the ability to use an app to change settings and schedule temperatures remotely.

For a large commercial space or workshop, this feature can be particularly convenient.

The manager can adjust the temperature before occupants arrive, change schedules, or check settings without having to be physically in front of the remote control.

Automatic vertical and horizontal louvers

The AirGreen product sheet confirms automatic vertical and horizontal louver control.

On a unit with such a high airflow rate, this is not merely a comfort feature.

Airflow direction directly affects how the 36,000 BTUs are distributed throughout the room. We therefore use louver movement in addition to proper indoor-unit placement.

However, even the best air-sweeping system cannot effectively get around several partitions. That is why the building layout remains central when choosing a single-zone mini-split.

Warranty: a difference to verify before purchase

The AirGreen product sheet shows:

10-year compressor – 10-year parts – 0-year labor, with additional warranty coverage possibly available.

The Senville brochure provided states:

5-year compressor – 5-year parts.

The same documentation specifies that installation by an authorized technician is required and that professional installation is necessary to maintain coverage and ensure compliant operation.

This difference between the manufacturer's basic warranty and the warranty advertised by AirGreen must be confirmed according to the applicable program, product registration, and sales terms at the time of ordering.

We always recommend that the customer keep:

• the invoice;
• serial numbers;
• proof of installation;
• warranty registration information;
• the documents associated with any additional warranty.

What we verify before installing a 36,000 BTU LETO

With a heat pump of this capacity, our preparation focuses on several elements that can completely change the final result.

We first validate the thermal load and space configuration. Next come the evaporator location, airflow path, and the possibility of running the 3/8 in – 5/8 in lines to the condenser.

We also confirm the electrical circuit corresponding to the 33 A MCA and 35 A MOP, then determine an outdoor location sturdy enough for a unit weighing nearly 143 lb.

In winter, we also plan the space around the condenser so that snow, ice, and water from defrosting do not interfere with its operation.

These are less visible elements than a SEER2 rating or a Wi-Fi function, but they are often what determines whether an installation will remain practical for many years.

The SENVILLE LETO 36,000 BTU in brief

The SENVILLE LETO SENL-36CD-OL / SENL-36CD-ILL is clearly intended for projects where high cooling capacity and strong airflow are required in a single zone.

Its main technical specifications are solid and easy to identify: 36,000 BTU, 18 SEER2, DC Inverter technology, R-454B, Wi-Fi, Alexa compatibility, substantial modulation, 3/8 in – 5/8 in piping, and a 208/230 V power supply.

Its main limitation for the Quebec market is also clear: it is not an ENERGY STAR Cold Climate model, and its heating capacity decreases considerably at very low temperatures.

For some projects, this compromise is perfectly reasonable. For others, particularly when winter heating is the absolute priority, we may recommend a heat pump with higher low-temperature capacity.

At AirGreen, our job is precisely to make this distinction before the equipment is installed.

For a SENVILLE LETO 36,000 BTU installation in Montreal, Laval, Longueuil, on the South Shore, the North Shore, or elsewhere in Greater Montreal, contact AirGreen. We can verify the sizing, electrical supply, unit locations, and building configuration to prepare a quote tailored to the project.