Installation of a Sharp ZU1 wall-mounted heat pump in Plateau-Mont-Royal
Flat roof installation of a Sharp ZU1 wall-mounted heat pump in Plateau-Mont-Royal. Raised support, waterproof penetration, quietness, and winter performance. AirGreen: HVAC experts for Montreal, Laval, Longueuil, North Shore, and 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.
A clean and durable flat roof installation, designed for Montreal's urban life
At AirGreen , we have just installed a Sharp ZU1 wall-mounted heat pump on the flat roof of a triplex in the Plateau-Mont-Royal . The context is typically Montreal: narrow streets, mature trees, compact volumes, access via exterior stairs and high requirements in terms of silence and efficiency. Our mandate: to offer four-season comfort while protecting the roof's waterproofing and maximizing the longevity of the equipment.
Client background and objectives
The owner wanted to replace an old seasonal air conditioner with a high-performance HVAC solution for heating and cooling, capable of maintaining comfort at -25°C without skyrocketing the energy bill. He also wanted to declutter the backyard and limit noise for the neighbors. The chosen configuration— a Sharp ZU1 condenser on the roof, a wall-mounted indoor head in the open area—meets these expectations precisely: efficiency, discretion, and elegant integration into the home.
Why Sharp ZU1 for a flat roof in Montreal
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High-efficiency inverter compressor and R-32 refrigerant , with lower climate impact than R-410A.
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High efficiencies in both summer and winter (competitive SEER and HSPF), suitable for peak heat and persistent cold.
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Ion Plasmacluster Technology : an asset for improving indoor air quality when windows remain closed for long periods.
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Quiet operation – ideal for the dense Plateau environment.
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Compatibility with certain subsidies when efficiency criteria are met, useful for making the investment profitable.
Installation architecture: stability, silence and watertightness
Support on risers
We built a Unistrut frame on concrete footings to raise the condenser and distribute the loads . Two treated wood side members act as intermediaries to absorb irregularities and facilitate roof maintenance. Anti-vibration pads under each support point reduce sound transmission to the structure.
Penetration management
The insulated refrigeration lines and power cable run around the perimeter, then cross the roof at a single point equipped with a metal flashing and an elastomeric membrane-compatible sealant , complying with waterproofing regulations. This approach simplifies future inspections and limits the risk of infiltration.
Clearances and blowing
The condenser is positioned away from the guardrail and possible air returns (outlets, parapets, trees). Side and rear clearances are respected to avoid recirculation of hot air in summer and optimize defrosting in winter.
Refrigeration path and power supply
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Connection length : approx. 7 to 9 m between the head and the condenser, ideal length to limit pressure drops and pressure losses.
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Bending radius respected** to preserve the integrity of the copper tubes.
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Discreet capping on the rear facade leading to the roof, harmonizing with the existing colors.
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Dedicated electrical circuit with appropriate circuit breaker and compliant cable section ; a disconnect box is accessible near the condenser for maintenance.
Condensate management: summer and winter
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Air conditioning (summer) : gravity discharge onto the roof, away from traffic areas, to avoid puddles and traces.
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Heating (winter) : Defrost water is drained away from the base of the unit to prevent ice formation. Raising the chassis protects the equipment and facilitates drainage.
Security and logistics in urban environments
Installing and handling a condenser on a flat roof in Plateau requires precise logistics :
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Lifting plan and safe route to the roof.
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Mechanical protection of the membrane during movement.
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Calibrated tools (torque wrench, micron vacuum pump, digital pressure gauges) for deep vacuum and loading to the manufacturer's weight .
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Complete functional tests : intensity, pressures, subcooling/superheating, cold and hot mode testing.
Finishing, commissioning and documentation
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Nitrogen + soapy water leak test on each flare.
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Vacuum < 500 microns before opening the fluid.
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Setting the modes, calibrating the shutters, explaining the eco-functions to the customer (temperature ranges, continuous ventilation, automatic restart).
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Provision of a maintenance guide : filter washing, clearances to maintain, annual maintenance frequency.
Results obtained
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Noise drop felt on the rear alley compared to the old unit: the immediate neighborhood only hears a slight hiss.
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Thermal stability of the housing: reduced variations, better homogeneity between rooms.
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Energy bill : significant savings expected thanks to mid-season heating efficiency and short peaks in very cold weather, compared to electric baseboards alone.
AirGreen Tips for Flat Roof Installation
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Raise the device : 20–30 cm of clearance prevents contact with snow and water.
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Anticipate the wind : strong anchors and judicious orientation reduce stress on the fan.
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Protect the membrane : pads/soles + sliding tapes to prevent abrasion.
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Avoid recirculation : no obstacles less than 30 cm behind and 60–100 cm in front, depending on capacity.
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Maintenance Plan : Annual HVAC maintenance extends life and maintains performance (coil cleaning, electrical check, inverter settings).
HVAC Maintenance: What We Do During the Annual Visit
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Deep cleaning of the internal exchanger and condensate tray to counter biofilm and odors.
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Checking operating pressures and power consumption .
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Inspection of the chassis and anchors , tightening if necessary.
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Defrost testing before winter: confirmation of trigger temperatures and cycle time.
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Updated usage advice based on customer habits and new features.
Grants and funding
Depending on the exact configuration and measured returns, the assistance programs available in Quebec can help reduce the net cost of the project. We assist our clients with eligibility analysis and document preparation. At the same time, our installment payment options allow you to spread out the investment while enjoying immediate convenience.
What the customer remembers
“Quiet, efficient, and with no visible pipes on the facade. The installation on the roof is clean and frees up space in the courtyard. The AirGreen team explained everything clearly, from usage to maintenance.”
Why entrust your HVAC installation to AirGreen?
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Montreal flat roof specialists (Plateau, Rosemont, Le Sud-Ouest, Ville-Marie): we understand access, waterproofing and neighborhood constraints.
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RBQ certified team and standardized procedures: traceability of each intervention.
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Complete service : load study, equipment selection, HVAC installation , HVAC maintenance , and priority after-sales support.
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Greater Montreal coverage : Montreal, Laval, Longueuil, North Shore, South Shore .
Conclusion
This Sharp ZU1 wall-mounted heat pump installation on a flat roof in Plateau-Mont-Royal demonstrates that a well-sized and properly supported system can offer silence, efficiency and durability in the heart of Montreal. With careful support , sealed penetrations and rigorous commissioning , the client benefits from four-season comfort, a better controlled bill and architectural integration that respects the neighborhood. AirGreen has created a clean, sustainable project that is ready to face both the July heatwaves and the January cold.
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).