Installation of a Sharp ZU1 series wall-mounted heat pump in Rosemont–La Petite-Patrie
AirGreen installs a Sharp wall-mounted heat pump (ZU1 range, R-32) in Rosemont–La Petite-Patrie: short path, gravity drainage, winter/summer efficiency. HVAC installation and HVAC maintenance for Montreal, Laval, Longueuil, North Shore, South Shore.
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.
Calibrated comfort for a Rosemont plex, designed for Montreal winters and optimized by our careful HVAC installation .
Project context and comfort objectives
In this typical Rosemont–La Petite-Patrie apartment, our client was looking for a discreet, efficient heating and cooling system capable of maintaining a stable temperature during freezing temperatures and heat waves. We recommended a Sharp ZU1 series wall-mounted heat pump (R-32 refrigerant), known for its low-temperature performance and precise air distribution. The goal: reduce energy bills, improve air quality, and improve operating silence, while preserving the interior aesthetics.
Chosen configuration: compact wall head, short path and gravity drainage
The indoor head is installed very high under the ceiling, near a wall facing outside. This position ensures minimal stratification and homogeneous diffusion thanks to the wide-range directional dampers. The drilling is carried out directly behind the unit for a short refrigerant path (≈ 1.5 to 2.5 m to the outdoor condenser), limiting pressure losses and maximizing efficiency. The condensate drain operates by gravity , avoiding the addition of a pump and reducing maintenance. The assembly is sealed and insulated to eliminate any air or vapor infiltration.
Why the Sharp ZU1 range for a Montreal plex
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Cold climate performance : the ZU1 range maintains reliable heating performance in negative temperatures, perfectly suited to the winter peaks of Montreal , Laval and the North Shore / South Shore .
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R-32 : Lower GWP refrigerant than R-410A, improving seasonal efficiency and environmental footprint.
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Quiet : The indoor head offers a very low noise level, ideal for an open living room or office space.
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Air quality : multi-layer filtration and laminar flow that limit stagnation zones.
Key steps in our HVAC installation
1) Load study and choice of sizing
We validate the power (BTU/h) based on the volume to be treated, the orientation of the windows and the insulation. In this Rosemont plex, solar gains in summer and losses through walls in winter require precise sizing to avoid oversizing (short cycles, discomfort) as well as undersizing (lack of heating in very cold weather).
2) Clean and watertight drilling
The drilling is aligned with the unit's axis for a straight path. We install an insulated sleeve and a vapor barrier to prevent moisture from passing through the wall—a crucial point in our climate. The drain slope is controlled for a natural flow, without gurgling noise.
3) Refrigeration lines and wiring
The copper tubes are flared to the torque , under nitrogen to prevent oxidation. We respect the bend radii and install continuous insulation (high density cellular) on the liquid and gas. The communication/power cable is fixed along its entire length; each penetration is caulked with an outdoor compatible sealant.
4) Pressurization, vacuuming and leak testing
We pressurize the circuit with nitrogen (calibrated pressure gauges) then create a deep vacuum (≤ 500 microns) controlled by a digital vacuum gauge. The stability of the vacuum confirms the tightness and the absence of humidity, an essential condition for the compressor's longevity and seasonal performance.
5) Start-up, air balancing and setup
After releasing the fluid, we take temperature and differential readings, check the intensity and adjust the shutter angles to cover the living areas without direct air flow. The heating mode is tested long enough to stabilize the measurements and validate the recovery after defrosting.
Visible implementation details and best practices
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Ceiling height : the unit is installed a few centimeters from the ceiling, which promotes the induction and recovery of hot air in winter.
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Proximity to woodwork : the presence of a window requires fine control of the vertical sweep, in order to avoid localized contact with cold air.
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Short route : reduced linearity = less pressure loss = improved COP/HSPF.
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Accessibility : clear front hood for HVAC maintenance (filter cleaning, turbine inspection, coil).
Results obtained: comfort, silence and savings
From the moment it is put into operation, the housing gains in thermal stability . The defrost cycles remain discreet, the air sensation is soft thanks to the modulation. In summer, the air conditioning quickly lowers the interior temperature while effectively dehumidifying, which improves the perception of comfort without excessively lowering the setpoint.
Potential Grants and Eligibility
The high-efficiency R-32 systems in the ZU1 range generally meet the criteria of the programs in effect in Quebec when seasonal performance is certified (SEER/HSPF/XLTH depending on the configuration). Our team checks eligibility for you with the programs applicable in Greater Montreal ( Montreal , Laval , Longueuil , North Shore , South Shore ) and prepares the necessary supporting documents.
Recommended maintenance to maintain performance
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Filters : monthly rinse during peak periods; periodic replacement/inspection.
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Batteries : Annual professional cleaning to prevent fouling and loss of exchange.
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Condensates : check the slope and the siphon (if present) to prevent seepage.
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Outdoor unit : winter clearance (snow, ice), ground clearance and snow guard if necessary.
An AirGreen HVAC maintenance contract includes these checks, extends the life of the unit and maintains the advertised performance.
What to avoid when installing a Montreal plex
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Non-compliant distances between ceiling and casing: they disrupt suction and create noise.
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Unnecessary “S” shaped journeys : every bend degrades efficiency.
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Condensate pumps not essential: we favor gravity to reduce failure points.
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Drillings without vapor barrier : risk of condensation in the wall and mold.
Why entrust your project to AirGreen?
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Local expertise : hundreds of plex and condo projects in Rosemont–La Petite-Patrie , Plateau , Villeray , Le Sud-Ouest .
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Mastery of recent brands and ranges (R-32/R-454B): Sharp, Gree , Fujitsu , Midea , etc.
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Complete support : sizing, HVAC installation , validation of subsidies , and annual HVAC maintenance .
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Measurable quality : documented vacuum tests, traced tightening torques, end-of-project photos.
Tips for maximizing savings
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Stable setting : let the device modulate rather than multiplying ON/OFF back and forths.
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Shutters : for heating, aim at a slightly downward angle to push the hot air to the center of the room; for air conditioning, sweep more horizontally to promote cool stratification.
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Interior doors : open to air condition several adjoining rooms; closed to target a specific area.
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Regular cleaning : a few minutes a month are enough to keep the heat pump at its best.
Report on the construction site in Rosemont–La Petite-Patrie
The Sharp ZU1 series wall-mounted heat pump and short-path installation offer a reliable solution for urban housing in Greater Montreal. Customers benefit from four-season comfort , remarkable silence , and tangible energy savings. Our method—calculation, drilling precision, deep vacuum, and fine-tuning—guarantees long-lasting performance and simplified maintenance.
Do you have a similar project in Montreal, Laval, Longueuil, North Shore or South Shore?
At AirGreen, we take care of everything: design, selection of the right heat pump , compliant HVAC installation , and planned HVAC maintenance . Contact us for a technical visit and a detailed quote tailored to your home and budget.
Meta Quick Tips
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For an open-plan living room/kitchen: choose a high, central location, away from ceiling drops that block the flow.
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For a bedroom: select a “quiet” mode and program night scenes.
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For a condominium: check the regulations relating to outdoor units (margins, snow guards, noise levels).
How it goes, from the first call to the end
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 the unit delivers when it is cold
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.
And at your place?
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.
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.
Which type of equipment for your project?
Pick what looks like your need.
Four mistakes we do not make
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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).