Installation of a Sharp ZU1 wall-mounted heat pump in Mercier–Hochelaga-Maisonneuve
Installation of a Sharp ZU1 on a flat roof in Mercier–Hochelaga-Maisonneuve : anti-vibration mounts, watertight penetrations, stable performance in extreme cold. AirGreen, your HVAC expert for Montreal , Laval , Longueuil , North Shore and 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
A flat roof, two compact condensers, a clear view of Montreal 's East End: today's project perfectly illustrates our expertise in HVAC installation in urban plexes. At AirGreen, we're modernizing the comfort of a rental building in Mercier–Hochelaga-Maisonneuve with a Sharp ZU1 wall-mounted heat pump for one unit, and upgrading the neighboring condenser belonging to another unit. The goal: four-season reliability, low noise, and optimized performance in both heat waves and extreme cold .
Why the Sharp ZU1 series for an urban plex
The Sharp ZU1 (new generation R-32 ) meets the constraints of central buildings: reduced size, high efficiency, quiet operation and low temperature performance. For occupants, this translates into:
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stable heating until the very cold thanks to the range's defrosting algorithms;
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uniform cooling without drafts thanks to fine control of the interior fan;
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significant energy savings compared to older R-410A appliances;
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eligibility for major local grants when seasonal performance criteria are met.
Building context and choice of location
Typical HoMa building with a flat roof, perimeter parapets and technical access from an interior hatch. The owners wanted:
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avoid any transmission of vibration to the housing;
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preserve the waterproofing of the bituminous coating;
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facilitate seasonal maintenance.
We therefore opted for installation on roof supports with anti-vibration pads and treated rails, leaving peripheral clearance for suction and blowing. The refrigeration path favors a vertical rise through an existing technical chimney then a gravity passage in the interior walls towards the wall head. The condensate drain from the indoor unit is recovered by gravity up to a protected waterfall; no condensate pump is necessary here, limiting noise and maintenance.
Salient technical details of the installation
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Machine type : wall-mounted heat pump (mini-split).
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Brand : Sharp .
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Range : ZU1 R-32 series (capacity adapted to the volume of the accommodation).
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Supports : rails on EPDM pads for load diffusion and vibration decoupling.
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Electricity : outdoor junction box and heating cable provided for the housing if required by winter conditions; dedicated circuit breaker for the housing panel.
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Refrigeration : insulated copper connections, nitrogen brazing , deep vacuum (≤ 500 microns) with nitrogen leak test; additional charge calculated according to the actual length.
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Roof protection : distribution mat under supports, sealing of crossings with sleeves and bitumen-compatible membranes.
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Noise : installation at a distance from the parapet to break up sound reflection; orientation of the blowing towards the free zone.
The cumulative length of the links is within a typical range for a plex (approximately 12 to 15 m), which maintains low pressure losses and high seasonal efficiency .
Construction stages and AirGreen guarantees
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Preliminary checks : structural load of the roof, condition of the covering, available routes, proximity of the electrical panel .
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Installation of supports : wedging, leveling, snow protection not required here but included in the estimate if exposed to snowdrifts.
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Drilling : minimalist core drilling with vapor barrier and sealing return ; waterproof cable glands.
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Installation of connections : careful bends, respect of curvature radii , continuous anti-UV insulation on the surface.
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Tests : nitrogen pressurization, vacuum and stabilization ; progressive start-up with superheat and subcooling control.
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Finishing : orderly paths, discreet capping at interior exits, electrical markings, roof markings.
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Delivery : explanation to the customer, HVAC maintenance schedule, registration for the manufacturer's warranty and ours on the installation.
Measured results and daily comfort
From the moment of commissioning, the indoor air temperature is stable, with remarkably low noise levels. On the roof, the perceived sound pressure level remains compatible with the coexistence of the two visible condensers: ZU1 and the neighboring unit that has been brought up to standard. The layout avoids air recirculation and allows free access to the hoods for maintenance, which speeds up interventions and reduces long-term costs.
Maintenance recommended to last in the Montreal climate
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Spring : gentle washing of the external battery, checking of the fixings and supports; checking of the clearances around the condenser (leaves, debris).
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Summer : Clean the interior filters every 4 to 6 weeks during periods of high use.
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Autumn : Inspection of the condensate drain and the crankcase heating cable if applicable.
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Winter : regular clearance in case of blown snow ; maintenance of an air corridor around the device to avoid persistent frost.
An AirGreen HVAC maintenance plan ensures consistent performance and preservation of seasonal efficiencies .
Grants and programs to consider
For a high-performance R-32 wall-mounted heat pump with efficient operation in cold weather, homeowners can check eligibility for active programs in Quebec (e.g., residential energy efficiency components). We help document the file: AHRI number, proof of professional installation, photos of serial numbers , and required forms. The Montreal , Laval , Longueuil , North Shore and South Shore areas are covered by our teams, which facilitates visits and document preparation.
Common pitfalls… and our solutions
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Devices installed directly on the membrane : risk of imprinting and punching. We use wide bases and distribution rails.
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Poorly sealed penetrations : infiltration and detachment of bitumen. We apply compatible sleeves and careful sealing return.
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Lack of clearance around the condensers**: air recirculation, frost, noise. We respect the manufacturer's clearances and orient the units to limit reflections.
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Unprotected wiring : UV, ice, breakage. We sheath and secure each section, with service loops for maintenance.
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Undersizing : short cycles, discomfort. Our load calculations take into account the envelope, solar gain, and occupancy rate.
What the occupants actually gain
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Stable comfort in living rooms in summer and winter;
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Better controlled energy bills thanks to the seasonal performance of the Sharp ZU1 ;
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Remarkable silence inside and minimal nuisance outside;
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Easy maintenance and safe access for technicians on the flat roof.
AirGreen in Greater Montreal
Our teams work daily in Montreal , Laval , Longueuil , the North Shore and the South Shore for residential and multi-unit HVAC installations . Each project benefits from a dedicated team leader , final quality control and personalized advice to maximize the durability of the equipment.
In short : This Sharp ZU1 wall-mounted heat pump installation on a roof in Mercier–Hochelaga-Maisonneuve demonstrates a clean, robust integration designed for our climate. Planning a similar upgrade for your plex or condo? We offer a quick technical assessment, a clear quote, and a timeline tailored to your needs.
Keywords : heat pump , wall-mounted air conditioner , HVAC installation , HVAC maintenance , Montreal , Laval , Longueuil , North Shore , South Shore .
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).