Installation of a Sharp wall-mounted heat pump in a stairwell in Sainte-Dorothée (Laval)

In this contemporary house in Sainte-Dorothée, Laval , our clients had a problem well known to homes with cathedral ceilings: a double-height stairwell where heat rises and stagnates, while the ground floor remains cool in winter… and the upper floor becomes stifling in summer.

To stabilize the temperature on both levels, we installed aSharp wall-mounted heat pump , model Sharp THU 18,000 BTU , positioned high above a narrow window. This choice allows us to take advantage of natural air circulation while maximizing energy efficiency.

A volume that's difficult to control: the reality of high ceilings

The area to be air-conditioned and heated is typical of modern houses in Laval:

• Open stairwell connecting the ground floor to the upper floor;

• Very high ceiling, creating a large volume of air;

• Small horizontal window at the top of the wall, letting in natural light;

• All white walls, for a clean and bright look.

Before our intervention, the occupants observed:

• Excessive heat upstairs during a heatwave;

• A persistent cold near the onset of winter, despite the main heating;

• Significant temperature differences between the bottom and top of the staircase;

• A feeling of draft every time the front door opened.

The objective was therefore to treat the vertical volume rather than a single room, by choosing equipment that was sufficiently powerful and ideally positioned.

Solution choice: Sharp THU 18,000 BTU wall-mounted heat pump

For this type of configuration, we recommended a Sharp THU 18,000 BTU wall-mounted heat pump, operating on R-32 refrigerant.

This model is distinguished by:

• A capacity suitable for large open spaces such as stairwells and mezzanines;

• An inverter compressor that continuously modulates its power, avoiding sudden temperature variations;

• Excellent performance in air conditioning and heating , including during the harsh winters of Greater Montreal;

• Quiet operation , important for a circulation area used at all times of the day;

• A minimalist white facade that blends perfectly into a contemporary setting.

By sizing the heat pump to 18,000 BTU, we ensure efficient treatment of the air circulating between the ground floor and the upper floor, while allowing the main heating system to operate more comfortably.

A high-level positioning designed for performance

The photo clearly shows that the Sharp wall unit is installed very high on the wall , just below the horizontal window. This positioning is not accidental.

Why install the heat pump so high up?

1. Exploiting air stratification
   In double-height spaces, hot air tends to accumulate at the top. By placing the Sharp heat pump higher up, we can recover this air, treat it, and redistribute it more evenly downwards.

2. To serve as a thermal link between floors
   The staircase acts as a thermal chimney. The wall-mounted heat pump, located at the heart of this circulation, mixes the air from the two levels and reduces temperature differences between the entrance, the upper floor, and the stairwell itself.

3. Preserve the minimalist aesthetic
   Mounted high up, the device is visually discreet : it does not interfere with movement, furniture, or the hanging of pictures or mirrors on more accessible parts of the walls.

4. Proximity to the window
   The small window at the top creates a critical heating or cooling point. Positioning the Sharp THU directly beneath it helps to minimize the sensation of a cold wall in winter and localized heat in summer.

A technical installation that requires expertise

Installing a wall-mounted heat pump as high as the one shown in the photo is no simple task. Our AirGreen technicians took several precautions:

• Use of a professional aluminum ladder with stable and secure support points;

• Two technicians work to handle the unit at height;

• Anchoring the mounting plate in the wall structure to prevent any long-term vibration or deformation;

• Route refrigeration lines and electrical wiring to the outside, respecting the slopes required for condensate drainage;

• Installation and fixing of the drain pipe to remove water produced in air conditioning mode without risk of infiltration.

Throughout the installation, we respected the clearances recommended by Sharp around the unit, in order to preserve performance and ease of maintenance.

Outdoor unit and four-season operation

Outside, the Sharp compressor associated with this wall-mounted heat pump was installed on anti-vibration mounts, at a sufficient height to protect it from the accumulation of winter snow.

The complete system allows:

• Comfortable home air conditioning during heat waves in Laval;

• A very efficient auxiliary heater in spring, autumn and during milder winter days;

• A reduction in the load on the main heating system, which helps to lower the annual energy bill .

Thanks to inverter technology, the Sharp THU heat pump adapts its power to the actual demand, limiting on/off cycles and extending the life of the compressor.

Results for residents of Sainte-Dorothée

After commissioning, the owners noted several tangible benefits:

• Reduced temperature difference between the ground floor and the upper floor;

• Significantly improved comfort in the stairwell, with no areas of extreme cold or heat;

• More pleasant air circulation, even when the front door is frequently used;

• Reduced reliance on electric baseboard heaters during the shoulder seasons;

• Satisfaction with the silence of the device , despite its installation in a dominant position in the center of traffic.

The Sharp wall-mounted heat pump is now integrated as a true indoor climate management tool , and not just as a temporary air conditioner.

AirGreen: Custom-designed installations for homes with high ceilings

At AirGreen , we are used to working in complex contexts: cathedral ceilings, stairwells, mezzanines, rooms open on several levels, etc.

For your project in Laval or elsewhere in Greater Montreal, we support you in:

• The choice of capacity and model of Sharp heat pump (THU, TU, ZU1, ZHU1, etc);

• Analysis of air volumes and circulation between rooms;

• The optimal positioning of indoor units, even at height;

• A safe and compliant, clean and sustainable installation ;

• After-sales service, maintenance and usage advice.

If you live in Sainte-Dorothée, Duvernay, Chomedey or any other area of ​​Laval, and your house has a double-height staircase or a cathedral ceiling, a well-positioned Sharp wall-mounted heat pump can transform your daily comfort.