A cold wall head to tame... a stairwell
In a single-family home in Sainte-Rose (Laval) , we are modernizing comfort with a Fujitsu Orion XLTH (R-32) wall-mounted heat pump installed high above a stairwell window . The goal: to distribute air efficiently between two levels while maintaining a sleek aesthetic and quiet operation on a daily basis.
The context: a demanding air column
Stairwells are among the most difficult volumes to treat in HVAC :
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strong air stratification (warm at the top, cooler at the bottom);
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high working heights ;
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air circulation which must supply two floors (ground floor and upper floor) without creating unpleasant currents.
Here, the house has a bright landing , a decorative shelf and an ideal clearance above the window: it's the perfect point for an adjustable wall head , capable of pushing air towards the upper floor and towards the corridor below .
Why the Fujitsu Orion XLTH (R-32)
The Orion XLTH range was designed for our Quebec winters:
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Stable extreme cold performance down to −26°C (and XLTH+ down to −30°C depending on capacity), ideal for Laval , Montreal , Longueuil , North Shore , South Shore .
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R-32 (A2L) refrigerant : better seasonal performance and reduced climate impact compared to R-410A.
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Wide-range inverter modulation : the device slows down finely once the temperature is reached, reducing noise and consumption.
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Careful acoustics : essential in an open passage area, sometimes close to bedrooms.
Design of the HVAC installation in a stairwell
Blowing installation and settings
We place the inner head at the upper lintel , centered on the window axis. This positioning provides:
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a natural draft : the treated air goes down the flight of stairs and is distributed on the ground floor ;
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an air blade oriented in vertical + horizontal sweep to supply the upstairs corridor;
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easy access for HVAC maintenance (filters, cleaning), despite the height — we provide a secure stepladder for annual visits.
AirGreen Tip: We set a slightly downward flap angle in cool mode to counter stratification and a gentle sweep in heat mode to carry warm air downwards without discomfort.
Drilling, lines and condensate drainage
The configuration allows a short drilling towards the outside (peripheral wall), with:
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insulated refrigerant lines (≈ 3 to 5 m),
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inter-unit communication and power cable ,
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gravity evacuation of condensates (controlled slope), without lifting pump — a guarantee of silence and reliability .
On the facade, we install a stable white UV capping to protect and standardize the path. The condenser is installed on anti-vibration wall brackets (or on a slab depending on the facade), clear of the snow cover.
Commissioning methodology
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Careful flaring , lubrication and controlled tightening torques.
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Nitrogen test and deep vacuum (≈ 500 microns) to guarantee a perfect seal .
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Opening valves and checking for superheat/subcooling .
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Acoustic measurements and flow adjustment to validate diffusion between levels.
Sizing and expected comfort
Selected capacity
For an average-sized Laval house with an open stairwell, the 12,000 to 15,000 BTU range covers the majority of needs:
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rapid cooling of the landing and lowering of the temperature on the ground floor;
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very effective heating supplement in mid-seasons and as support during winter peaks;
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optimized consumption thanks to fine modulation in partial load (the most frequent situation).
Acoustics and air quality
The Fujitsu head works at very low speed at night. The noise level remains discreet , even in the staircase which acts as a reverberation box . The washable filters can be removed in a few seconds; we recommend cleaning every 6 to 8 weeks during the season.
Results for the family
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More uniform temperature between the two floors: no more overheated upstairs and chilly ground floor.
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Reduced humidity in summer thanks to the controlled “Dry” mode.
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Controlled operating costs : the inverter compressor avoids energy-consuming short cycles.
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Aesthetic integration : cream/white silhouette that blends into the decor, zero floor equipment in the staircase.
Technical details and best practices
Daily use
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In summer : slightly low blowing angle, doors open to help diffusion towards the rooms.
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In the off-season : Heat mode with moderate setting (20–21°C), priority given to continuous operation rather than on/off.
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Winter : Allow the unit to defrost automatically ; avoid obstructed air vents on the condenser.
HVAC Maintenance
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Annual AirGreen inspection : pressures, electrical, condensates, exchangers, calibrations.
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Filters : rinse with lukewarm water, dry completely before replacing.
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Exterior check after storms: clearing snow/frost around the condenser and capping .
Mistakes to avoid
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Install the head too low in the staircase: risk of shock and poor air intake .
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Condensate pump unnecessary: noise, maintenance; gravity remains the #1 solution when the slope allows it.
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Close adjacent doors in air conditioning mode: the air column loses its distribution effect.
Grants and support
High-efficiency R-32 wall-mounted heat pumps may be eligible for financial assistance (depending on current criteria: capacity, efficiency, cold performance, etc.). Our team supports homeowners in Greater Montreal with:
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validate eligibility ,
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prepare the files ,
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size the equipment to maximize savings on the energy bill.
Why entrust your project to AirGreen?
At AirGreen, each HVAC installation is sized , implemented and validated according to the building's constraints. Stairwells, mezzanines, attics: we use architecture to transport useful air where it counts, without compromising on safety , site cleanliness and sustainability .
Keywords : heat pump , wall-mounted heat pump , Fujitsu Orion XLTH , HVAC installation , HVAC maintenance , Montreal , Laval , Longueuil , North Shore , South Shore , R-32 , stairwell .