Installation of a Sharp ZU1 wall-mounted heat pump in Villeray (Montreal)
AirGreen installs a Sharp ZU1 wall-mounted heat pump in Villeray. The heat pump is located at the top of the stairs to heat and cool two levels with controlled energy consumption. Installations are available in Montreal, Laval, Longueuil, the North Shore, and the South Shore.
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The job on one screen
The unit’s data sheet
The range as published on airgreen.ca: pick a size to see its capacity in deep cold.
| Size | Heating at −8 °C | Heating at −15 °C | Coldest certified point | COP at −15 °C | SEER | HSPF | Indicative LogisVert aid |
|---|---|---|---|---|---|---|---|
| Sharp ZU1 12 000 | 14,500 | 12,000 | −27 °C: 7,200 | 2.11 | 22.0 | 11.0 | $1,740 |
| Sharp ZU1 15 000 | 18,100 | 15,300 | −27 °C: 10,100 | 2.1 | 24.0 | 11.0 | $2,172 |
| Sharp ZU1 18 000 | 22,000 | 18,000 | −27 °C: 11,500 | 2.2 | 24.0 | 11.0 | $2,640 |
| Sharp ZU1 24 000 | 22,400 | 19,000 | −27 °C: 12,300 | 2.2 | 22.0 | 11.0 | $2,688 |
According to NEEP, it delivers 14,500 BTU/h at −8 °C (17 °F), more than at 8 °C (14,000 BTU/h). It heats as hard in moderate cold as in mild weather.
According to NEEP, its certified maximum capacity at −27 °C (−17 °F) is 7,200 BTU/h, 60% of its nominal 12,000 BTU size.
At 8 °C, its certified maximum capacity reaches 17,100 BTU/h, 42% more than its nominal 12,000 BTU size.
According to NEEP, it delivers 18,100 BTU/h at −8 °C (17 °F), more than at 8 °C (18,000 BTU/h). It heats as hard in moderate cold as in mild weather.
According to NEEP, its certified maximum capacity at −27 °C (−17 °F) is 10,100 BTU/h, 67% of its nominal 15,000 BTU size.
At 8 °C, its certified maximum capacity reaches 21,800 BTU/h, 45% more than its nominal 15,000 BTU size.
According to NEEP, it delivers 22,000 BTU/h at −8 °C (17 °F), more than at 8 °C (21,600 BTU/h). It heats as hard in moderate cold as in mild weather.
According to NEEP, its COP at −27 °C is 1.88: the highest of the ZU1 line, which ranges from 1.79 to 1.82 at that temperature.
According to NEEP, its certified maximum capacity at −27 °C (−17 °F) is 11,500 BTU/h, 64% of its nominal 18,000 BTU size.
At −27 °C, its certified minimum capacity is 3,200 BTU/h (5,500 at 8 °C). It slows down instead of cycling on and off.
According to NEEP, its certified heating capacity at −15 °C (5 °F) is 19,000 BTU/h, 79% of its nominal 24,000 BTU size. Its COP there is 2.20.
Data read live from the airgreen.ca page of each size (NEEP / AHRI certified performance). When the title names the installed size, it is highlighted; otherwise the whole range is shown. The aid shown is today’s, using Hydro-Québec’s rule ($120 per 1,000 BTU/h at −8 °C); amounts quoted in the article date from its publication. Only Hydro-Québec confirms the assistance granted.
The article, chapter by chapter
Full-height comfort: a wall-mounted headboard perfectly placed in the stairwell
At AirGreen , we have just installed a Sharp ZU1 (R-32) wall-mounted heat pump in a typical Villeray house. The project's unique feature: the indoor head is positioned at the very top of the stairwell , a strategic location for circulating air between the upper and lower floors. The result: consistent comfort on two levels, with fewer cold spots in winter and faster air conditioning in summer—all in a simple, discreet integration on a light-colored wall.
Why the stairwell is a winning location
A stairwell acts like a convection column . Warm air naturally tends to rise; cool air sinks. By placing a wall-mounted heat pump at this critical point, we exploit this natural movement to:
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Distribute heat to the upstairs bedrooms without overheating the living room;
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Bring the cooled air back to the ground floor in air conditioning mode;
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Reduce temperature deltas between rooms;
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Reduce the number of short cycles and optimize electricity consumption .
To amplify the effect, we set the diffusion flaps : a slightly upward angle in heating mode to push the air towards the landing, then a horizontal sweep in summer to break up the pockets of hot air at the top of the shaft.
The chosen solution: Sharp ZU1 R-32, 15,000 BTU
Capacity and series. The Sharp ZU1 chosen here in 15,000 BTU comfortably covers an open space on two levels, typical of Villeray homes. The ZU1 series, with inverter compressor and R-32 refrigerant, offers an excellent efficiency/compactness ratio and very low noise level - ideal for a passage and rest area.
Main highlights:
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Extreme cold : stable performance down to -25°C , adapted to the Montreal climate;
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R-32 : reduced climate impact and better volumetric capacity than R-410A;
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Quiet : quiet operation; no buzzing in the stairs at night;
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Filtration : multi-filters and precise blowing, limiting direct air currents.
Installation process: clean, robust and designed to last
1) Study and preparation.
Our technicians began with a thermal assessment of the house: volumes to be treated, ceiling height, permeability of doors and corridors, occupancy habits. This allowed us to confirm the capacity of 15,000 BTU and to validate the location at the top of the wall , above the stair chases, away from the angles that block diffusion.
2) Drilling and crossing wall-to-wall.
We made a single sloping hole for gravity condensate drainage. The refrigerant connections and power cable are grouped together and sealed to prevent air infiltration. The slope ensures that the drain flows naturally to the outside, without a pump (increased reliability, reduced maintenance).
3) Finishes and aesthetics.
The connections are protected by discreet capping coordinated with the color of the wall. The old fixings visible on the wall were neatly filled ; a touch-up of paint was recommended to the client for a perfect finish. The head fixing plate is laser-leveled , preventing any vibration and condensation leaks.
4) Vacuuming and loading.
After crimping, we performed a deep vacuum and an extended leak test to ensure the absence of moisture and micro-leaks in the circuit. The ZU1's electronic parameters (line length, height compensation) were programmed according to the actual configuration.
5) Start-up and air balancing.
In commissioning, we set the automatic speed and defined two user scenes :
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Winter : upward blowing + slow sweeping to promote controlled stratification;
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Summer : almost horizontal diffusion + faster sweeping to break up the accumulation of heat in the upper part.
Integration with everyday life: measurable comfort, controlled consumption
In this project, the house had a differential of 3 to 4 °C between the landing and the living room during cold peaks. From the first week of use, the client reported a difference reduced to 1 °C , a sign of successful air distribution . In summer, fresh air precedes the occupants: when going down the stairs, you enjoy a uniform sensation of freshness , without localized drafts.
On the expense side, inverter technology limits full-power starts. The machine continuously modulates to maintain the setpoint, which reduces consumption and ambient noise . Over the course of a season, the ZU1 advantageously replaces a window air conditioner and relieves the burden on existing electric convectors.
AirGreen Operating Tips for a Stairwell
To get 100% of the potential of a wall-mounted heat pump in a stairwell:
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Smart setpoint. Aim for 21°C to 22°C in winter. Avoid alternating between complete stops and large-scale restarts; constant modulation is more economical.
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Interior doors. Leave doors ajar during busy hours to facilitate air circulation between levels.
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Fins. In winter, a slightly upward angle; in summer, horizontal . Automatic sweeping should be slow for heating, medium to fast for cooling.
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Filtration. Clean filters every 6 to 8 weeks (more often if pets or dust are present).
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Exterior clearances. Ensure clearances around the condenser (snow and vegetation), especially on the discharge side.
Grants and Compliance: What You Need to Know in Montreal, Laval, Longueuil, North Shore and South Shore
High-efficiency R-32 wall-mounted heat pumps are often eligible for Quebec's support programs when they meet the required performance thresholds and cover a significant portion of your heating needs. Our team handles:
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Check the eligibility of the Sharp ZU1 indoor unit/condenser pair;
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Provide proof of installation and necessary settings ;
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Advise on heating strategy to maximize real savings and the value of aid .
We support our clients throughout Greater Montreal — Montreal , Laval , Longueuil , North Shore and South Shore — to make the administrative side simple and quick .
What distinguishes an AirGreen installation
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Correct sizing (neither undersized nor oversized) thanks to our thermal balances .
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Quality of fittings : calibrated flares, controlled tightening torque, documented vacuum draw.
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Connection route designed for maintenance (clean access, gentle elbows, UV protection).
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Finishes : harmonized cappings, waterproof seals, identified wiring .
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Service : Annual HVAC check reminder and maintenance offered to preserve the manufacturer's warranty and performance.
Bottom line: a ZU1 that works for two levels, discreetly
This Sharp ZU1 installation in Villeray solves a common problem in Montreal homes: maintaining consistent temperatures between floors without multiplying the number of appliances. By leveraging the geometry of the stairwell and inverter modulation, we deliver four-season comfort with low power consumption—and an aesthetic that respects the spirit of the home.
Whether you are in Montreal , Laval , Longueuil , on the North Shore or the South Shore , our AirGreen team designs HVAC installations that fit your architecture, your uses and your budget. Let's talk about your project: one well-placed head is worth two poorly positioned heads.
The job tools
Two quick checks with real numbers: what heat costs, and what your current heaters add up to in BTU/h.
Baseboards and electric furnaces turn 1 kWh of electricity into 1 kWh of heat. A heat pump delivers more: that is its COP. At Hydro-Québec’s rate D (11.142¢/kWh above 40 kWh a day, since 1 April 2026):
Hydro-Québec: a heat pump can be up to three times more efficient than baseboards for heating in the colder months.
Estimate per kWh of heat, at the chosen temperature, using the certified COP from the product page. Taxes, access charge and backup heat not included.
Conversion: 1 W = 3.412 BTU/h. An indication, not a load calculation: baseboards and furnaces are often stronger than the real need, and they can stay as backup. AirGreen confirms the capacity on site.
How the job unfolds
The main steps of this kind of job at AirGreen. Every house has its quirks: the estimate brings them out.
We look at the room, the outside wall, the line route and where the outdoor unit will go. That is where the capacity gets chosen.
Model, capacity and price, in writing. We also check whether the model qualifies for assistance programs.
Floors and furniture protected, wall plate position marked level, wall opening located.
A single opening, with the slope the drain needs to flow outside.
Set on a stand raised above the snow, with the clearances the manufacturer requires.
Connected, insulated and protected. The opening is then sealed against water, cold air and insects.
A dedicated circuit and an accessible disconnect near the outdoor unit.
Leak test, vacuum, then start-up and a check of heating and cooling.
Remote, modes, filters: we show you the essentials before we leave.
- The on-site estimateWe look at the room, the outside wall, the line route and where the outdoor unit will go. That is where the capacity gets chosen.
- The quoteModel, capacity and price, in writing. We also check whether the model qualifies for assistance programs.
- Getting readyFloors and furniture protected, wall plate position marked level, wall opening located.
- The wall openingA single opening, with the slope the drain needs to flow outside.
- The outdoor unitSet on a stand raised above the snow, with the clearances the manufacturer requires.
- Lines, cable and drainConnected, insulated and protected. The opening is then sealed against water, cold air and insects.
- The electrical workA dedicated circuit and an accessible disconnect near the outdoor unit.
- Tests and start-upLeak test, vacuum, then start-up and a check of heating and cooling.
- The walkthroughRemote, modes, filters: we show you the essentials before we leave.
What we check on a job like this one
Each number is a point we check on site. Switch between summer and winter to watch air and heat move.
In summer, the outdoor unit rejects the house's heat outside.
Generic illustration of this type of installation, not a survey of this job site. Tap a number.
Mounted level on a wall plate, high enough for the air to reach the whole room, with enough space around it to slide the filters out easily.
The refrigerant lines, the communication cable and the drain go through the wall in a single opening, sealed against water, cold air and insects.
Two insulated copper pipes connect the two units. Outside, a line cover can protect them from sun, knocks and weather.
A shut-off switch near the outdoor unit isolates it safely for service. It must stay accessible at all times.
The compressor and the fan. In heating mode it captures heat from the outdoor air, even in winter, and moves it inside.
On the ground or on the wall, it keeps the unit above accumulated snow. The unit stays clear and defrost water can drain away.
The fan needs to blow freely. Storage, a fence or a wall too close, and efficiency drops while noise goes up.
Is your home ready?
Check what applies at your place. A "no" is not a refusal: it is what we sort out during the estimate.
Good habits, once the unit is in place
Six simple habits that keep the unit going. Your list stays on this device.
What to do, season by season
Three habits per season for this unit. They take a few minutes and prevent many calls.
- Clean the indoor unit's filters.
- Clear leaves and debris left on the outdoor unit by winter.
- Test cooling before the first hot days.
- Clean the filters more often when the unit runs a lot.
- Keep plants away from the outdoor unit.
- Check that no water drips from the indoor unit.
- Rake the leaves around the outdoor unit.
- Test heating before the first cold days.
- Book periodic maintenance before winter.
- Keep snow away from the stand and the front of the unit.
- Let the unit defrost: it is normal.
- Never hit the ice on the fins; call us if the unit stays iced up.
The right pages, at the right time
Four statements: true or false?
It all comes down to details you have just seen.
1. In heating mode, the outdoor unit can produce water.
During defrost cycles. That water must drain away without forming ice.
2. You pick the capacity with a simple square-footage rule.
Windows, insulation, orientation and how the room is used all count. Capacity is chosen on site.
3. A multi-zone connects several indoor heads to a single condenser.
One head per room, all on the same condenser. Each room keeps its own temperature.
4. The disconnect can sit behind the patio furniture.
It must stay accessible: it is what shuts the unit off for service.
0 / 4 right answers
What people ask us about this kind of work
Does a wall-mounted heat pump heat in winter?
Wall-mounted or multi-zone: how do I choose?
Where does the outdoor unit go?
Are there grants?
Do I need a permit?
How cold can it heat?
How much can I save?
How is the LogisVert assistance calculated?
Is it noisy?
The outdoor unit is covered in ice: is that normal?
Does AirGreen hold the required licences?
Is the estimate free?
No question matches. Write to us: we answer.
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Text and photo: a real AirGreen Climatisation & Chauffage job. The diagrams are generic illustrations of the type of installation, not a survey of this job site. Sources of the added figures: airgreen.ca product pages (NEEP / AHRI performance), Hydro-Québec (Heat pumps page, LogisVert, read on 13 October 2026), Régie de l’énergie (rate D as of 1 April 2026).