Installation of a Sharp ZU1 wall-mounted heat pump in Rosemont–La Petite-Patrie
Project in Rosemont–La Petite-Patrie: Sharp ZU1 wall-mounted heat pump (R-32), rear-wall penetration, gravity drain, nitrogen testing, and deep vacuum. Discreet finish and quiet comfort. AirGreen: reference HVAC installation in Greater Montreal.
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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
Optimized four-season comfort in a brick condo in the heart of Montreal
Context and objectives of the project
In a bright apartment in Rosemont–La Petite-Patrie , we are modernizing comfort with a recent Sharp ZU1 wall-mounted heat pump (R-32 refrigerant). The client was looking for an efficient solution for supplemental heating in the off-season and quiet cooling in the summer, without encroaching on the living space. The indoor unit is positioned high on a sleek wall, near a window overlooking a brick facade : a context typical of Montreal condos where a direct, discreet and short passage to the outside is preferred for the refrigeration piping and condensate drainage.
Why the Sharp ZU1 range for this home
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Energy efficiency : High-modulation inverter technology, high-performance compressor and low-GWP R-32 refrigerant.
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Acoustic comfort : low-noise interior ventilation, ideal for an open living room.
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Extreme cold : stable performance down to negative temperatures common in Montreal, for reliable heating support.
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Compact design : discreet white casing fits into modern interiors, without overloading the wall or hindering storage.
In short, the ZU1 meets the equation sought by many occupants of Greater Montreal : efficiency, silence and careful integration.
Installation of the indoor unit: precision and discretion
Choice of location
We attach the mounting plate to the thermal center of the wall : high enough for even air distribution, out of the direct flow of the window and clear of the side shelves. This alignment prevents cold air from recirculating against the glazing and ensures easy access for HVAC maintenance (filter, damper, cleaning).
Drilling and crossing
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Single drilling with a controlled outward slope (≈ 2–3°) to ensure gravity drainage of condensates.
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Rear wall outlet directly to the brick: short route (≈ 30–50 cm) limiting pressure losses, bends and noise.
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Waterproofing by vapor barrier sleeve + external sealing to eliminate air infiltration, insects and thermal bridges.
Refrigeration connections and power supply
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Continuously insulated 1/4"–3/8" refrigerant piping , length optimized to meet ZU1 nominal ranges.
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Inter-unit communication and power cable connected to the refrigeration line for a clean and minimalist look.
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Grounding and protection on a circuit breaker dedicated to the outdoor condenser, in accordance with the Canadian Electrical Code.
AirGreen Methodology: Measurable Quality at Every Stage
Commissioning checks and tests
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Flares dynamometer calibrated and lubricated to Sharp tolerances.
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High pressure nitrogen test to validate the tightness of all connections.
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Deep vacuum down to <500 microns, stabilized, to ensure the absence of moisture and non-condensables.
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Setting of ventilation, defrosting and room setting functions according to customer usage.
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Final measurements : blowing temperature, intensity, superheating/subcooling, noise level check.
These checks, carried out systematically, ensure seasonal performance (heating and air conditioning ), compressor longevity and the manufacturer's warranty .
Construction site challenges and solutions chosen
1) Load-bearing brick wall and clean openings
The urban brick environment requires a suitable core drill and careful sealing; we protect the interior finish and install a discreet rosette for impeccable aesthetics.
2) Condensate management without pump
The immediate proximity of the exterior wall allows for reliable gravity drainage : no lifting pump, therefore silence and reduced maintenance .
3) Clearances and air recirculation
To avoid dead zones near shelves, we follow Sharp's suggested clearances and adjust the louver orientation so that the flow runs along the ceiling and then smoothly down into the occupied area.
Results: tangible comfort and controlled bill
Upon startup, the room quickly reaches the setpoint without unpleasant drafts . In heating mode, the ZU1 maintains a stable, warm blowing despite the cold outside; in summer, dehumidification improves the feeling of freshness and nighttime well-being. The user benefits from reduced operating costs compared to resistive devices or an older non-inverter wall-mounted air conditioner .
HVAC Use and Maintenance Tips
Good daily practices
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Stabilize the setpoints: 21–23°C for comfort, avoid variations of ± 3°C multiple times per day.
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Allow the machine to modulate : open nearby interior doors to facilitate air diffusion.
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In summer, activate Dry mode during humidity peaks.
Annual maintenance recommended
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Cleaning filters and inspecting the fan.
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Gentle disinfection of the exchanger to prevent odors and biofilms.
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Checking the gravity drain and external waterproofing.
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Checking the connections and insulation of the refrigeration line.
Regular HVAC maintenance maximizes lifespan and preserves seasonal performance.
What to avoid (feedback from Montreal)
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Install too low : risk of direct blowing onto occupants and recirculation of hot air to the ceiling.
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Drillings without slope for condensates: cause of overflows.
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Long, unnecessary connections : pressure losses, noise and reduced efficiency.
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Poorly sealed capping on the outside: infiltration of cold air in winter.
Grants and local compliance
The recent wall-mounted heat pump , efficient in cold and low GWP refrigerant, is in line with the criteria generally eligible for grant programs in effect in Quebec for improving residential energy efficiency. We support our customers with documentation (detailed invoices, installation photos, serial numbers) to facilitate the application. Electrical and safety standards are respected for complete compliance in Montreal, Laval , Longueuil , North Shore and South Shore .
Why entrust your HVAC installation to AirGreen?
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Local expertise : hundreds of construction sites for plexes, condos and houses in Greater Montreal.
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Clean execution : short routes, clean finishes, careful seals.
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Measurements and reporting : we validate performance through instrumented tests .
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Follow-up : planned maintenance and advice tailored to your building.
Summary technical sheet (Rosemont–La Petite-Patrie project)
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Type : single-zone wall-mounted heat pump .
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Brand/Range : Sharp ZU1 (R-32).
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Layout : interior head of high wall, rear wall crossing towards brick.
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Evacuation : gravity (slope 2–3°), no pump.
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Refrigeration path : ultra-short, continuous insulation.
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Controls : nitrogen, deep vacuum, electrical/thermal measurements.
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Benefits : quiet comfort, energy savings, discreet aesthetics.
And what about your accommodation?
Whether you are in Montreal , Laval , Longueuil , on the North Shore or the South Shore , we size and install the most suitable solution: heat pump , wall-mounted air conditioner , multi-zone , or specific interior systems (cassette, console, ducted). Our promise: rigorous installation, measured performance and simple, clear and punctual service.
Next step
Request a technical assessment : An AirGreen advisor will analyze your room, its insulation, clearances, and the position of the outdoor condenser, then provide a detailed quote with maintenance options. Your future comfort starts today, with an HVAC installation that respects your space... and your energy bill.
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).