Installation of a Sharp ZU1 wall-mounted heat pump in Saint-Laurent
Saint-Laurent: AirGreen installation of Sharp ZU1 wall-mounted heat pumps on a flat roof, with raised supports and optimized service paths. Performance, quietness, and easy maintenance for lasting comfort in Montreal and the surrounding area.
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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
Two condensers on a flat roof, winter performance and careful finishing: the AirGreen signature
In Saint-Laurent , we completed a flat-roof HVAC installation designed to provide four-season comfort in a multi-unit residential building. The project included two Sharp Eco Inverter ZU1 series outdoor units mounted on raised supports with dedicated service paths. This configuration meets the constraints of a dense urban environment while maximizing heating reliability during Montreal's cold weather.
Why the Sharp ZU1 series for Saint-Laurent
In Greater Montreal, the ZU1 series wall-mounted heat pump stands out for its balance between energy efficiency , silence and air quality thanks to Plasmacluster Ion technology. For this project:
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The Eco Inverter compressor finely adjusts power and provides significant electricity savings .
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Stability in heating mode down to low temperatures responds to local cold peaks.
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The compact frame allows for discreet installation on a flat roof without encroaching on traffic areas.
We choose this model when the objective is to combine winter comfort , efficient air conditioning in summer and easy maintenance in an urban environment.
Building context and client objectives
The building has several apartments of varying sizes. The owners wanted:
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Standardize equipment to simplify maintenance and parts management.
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Avoid any encroachment on side walls visible from the street.
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Ensure safe access for maintenance without disturbing occupants.
The flat roof proved to be the best installation solution, with vertical passage of the refrigeration lines and the electrical supply in a central technical duct.
Technical architecture retained
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Device type: Sharp wall-mounted heat pump (ZU1 series), Eco Inverter outdoor units.
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Mounting: aluminum rails on mechanically fixed treated wooden runners , with anti-vibration pads under each support foot.
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Clearance under chassis: sufficient for the evacuation of defrost water and air circulation on gravel roofs.
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Refrigeration lines: vertical route by sealed piercing (vapor barrier + flashing), then UV capping towards the interior heads. Estimated cumulative length 12 to 18 m per system, continuously insulated.
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Power supply: dedicated 240 V circuits from the panel, with disconnect box near each condenser and grounding compliant with RBQ / Hydro-Québec .
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Internal condensate management: gravity with controlled slope; no pump required on this project.
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Service access: peripheral space respecting manufacturer clearances , rear and side clearance preserved for air flow .
Visible installation details and construction choices
On the roof, we favor modular aluminum supports : they resist corrosion and limit point loads. The treated wood pads distribute the load on the gravel and avoid any pressure points on the membrane. Anti-lift mechanical fasteners complete the protection against prevailing winds .
The refrigeration bundles and communication cables are connected and identified; they follow a short route to reduce pressure losses and facilitate future diagnostics. The exterior capping is chosen in a light gray shade to blend in with the roof relief and limit solar heating.
Interior integration and acoustic comfort
Each condenser serves a dedicated wall head per dwelling. Inside:
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The holes are made using a punch with vapor barrier packing to preserve the thermal envelope.
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The head mounts are lined with an anti-vibration gasket to reduce sound transmission to the walls.
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Airflow is adjusted room by room to avoid drafts in living areas.
The result: a very low noise level in automatic speed, perfect for rooms overlooking the courtyard.
Commissioning and quality controls
Our teams follow a constant protocol:
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Nitrogen test to confirm the tightness of the circuit.
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Deep vacuum with recorder, then stabilization .
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Power on and set seasonal modes.
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Verification of blown intensities and temperatures , with recording in the customer file .
This methodology guarantees increased compressor longevity and controlled consumption , both in winter and summer.
Results: constant comfort and savings
From the first week of operation, the occupants noted:
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Rapid temperature rise in cold weather thanks to inverter modulation.
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Consistent air conditioning during the hot July periods.
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An anticipated reduction in the bill thanks to the high coefficient of performance of the ZU1 series.
Annual HVAC maintenance remains simple: cleaning the interior filters, rinsing the exterior coils and checking the electrical tightenings.
Specifics of a flat roof installation in Montreal
Installing wall-mounted heat pumps on roofs requires special attention:
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Snow clearances : the elevation limits burial and facilitates the flow of defrosting water .
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Wind : orientation of the exchangers with their backs to the prevailing wind where possible, and suitable anchors .
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Waterproofing : all flashings are carried out with membrane repair and compatible mastic ; a vapor barrier is re-established after the conduits are installed.
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Maintenance : A clear technical aisle is maintained between the units for tool access and service measurements.
These points prevent unexpected shutdowns and extend the life of the devices.
Grants and Compliance
High-performance heat pumps like the Sharp ZU1 series may be eligible for certain assistance programs depending on the housing configuration and current criteria. We support our customers in the process and ensure compliance with RBQ , Hydro-Québec requirements and municipal regulations in Montreal, Laval, Longueuil, North Shore and South Shore .
AirGreen Tips for Owners and Managers
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Sizing : choose the BTU capacity according to the envelope and the actual use of the rooms.
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Short route : reduce line lengths to maintain seasonal yields .
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Raising : always use adjustable supports with anti-vibration mounts on flat roofs.
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Maintenance : Annual HVAC maintenance prevents efficiency losses and optimizes the warranty .
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Succession plan : in multi-unit housing, multiplying the units provides useful redundancy in the event of peak demand.
AirGreen, your HVAC reference in Greater Montreal
We design custom installations for Montreal , Laval , Longueuil , the South Shore and the North Shore . Our team understands the constraints of roofing and noise-sensitive interiors , and delivers clean, stable and easy-to-maintain systems. For a similar project in Saint-Laurent or elsewhere in Greater Montreal, we offer a technical visit and a detailed quote with implementation scenarios.
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).