Installation of a Sharp ZU1 wall-mounted heat pump in Rosemont–La Petite-Patrie
AirGreen installs a Sharp ZU1 R-32 in Rosemont–La Petite-Patrie: high wall head, gravity drainage, discreet finishes. High-performance heat pump for extreme cold and precise air conditioning, turnkey service in Greater Montreal .
Take a tour of the installation
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.
Consistent comfort between floors thanks to strategic installation in the stairwell
In this bright duplex in Rosemont–La Petite-Patrie , our team installed a Sharp ZU1 wall-mounted heat pump ( R-32 refrigerant), designed to provide reliable heating in extreme cold and precise air conditioning in the summer. The interior head is positioned high above the staircase to promote natural air circulation between the ground floor and the upper floor. This choice of installation transforms the staircase into a true vertical plenum , eliminating temperature differences from one room to another and reducing short cycles.
Residential context and comfort objectives
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Plexiglas-type house, light walls, woodwork and large side window: an open space where thermal stability and silence are desired.
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Priority need: distribute heat in winter without overheating the living room, and quickly lower the temperature of passage areas in summer.
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Constraints: significant working height and clearances to be respected around the device.
The AirGreen solution
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Sharp ZU1 wall-mounted heat pump (recent R-32 range), sized based on the surfaces to be treated and the insulation of the envelope.
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Orientation of the motorized shutters to sweep the stairwell and push the tempered air towards the adjacent rooms.
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Discreet gravity drainage (no condensate pump to maintain) and conduit covers matching the wall color for a clean finish.
Why the Sharp ZU1 R-32 is suitable for Montreal's climate
Yields and cold resistance
The Sharp ZU1 series is designed for Quebec's extreme cold with stable performance down to approximately −25 °C . Its variable-speed compressor limits sudden starts, improving durability and reducing electricity consumption . R-32 provides better heat transfer than previous-generation R-410A, allowing for competitive SEER/HSPF and a reduced carbon footprint .
Acoustic comfort and precision
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Very low interior noise level : ideal for a stair landing near bedrooms.
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Fine regulation : continuous variation prevents temperature yo-yo fluctuations, which are particularly noticeable in busy areas.
Eligibility for grant programs
Efficient wall-mounted heat pumps in this category are generally eligible for programs in effect in Quebec. We validate the current criteria for each address and prepare the claim file with the customer. Households in Montreal , Laval , Longueuil , as well as on the North Shore and South Shore , benefit from comprehensive support to maximize assistance.
Installation Details — What Makes the AirGreen Difference
1) Location and airflow
Placing the head high in the stairwell creates a reverse chimney effect in winter: the warm air propelled from the head gently descends to the ground floor, while the return air draws in cooler air from the upper steps. In summer, the fins are oriented to push cold air upstairs , balancing the bedrooms.
2) Drilling, lines and finishes
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Main borehole of small diameter, slopes respected for evacuation.
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Connection length optimized by a short path to the exterior wall located behind the head; this reduces pressure losses and facilitates maintenance.
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Discreet capping and solid fixings: the visual integration remains neat , without excess thickness around the wooden frames.
3) Condensates: priority to gravity
Choosing gravity drainage limits the risk of breakdowns and eliminates pump noise . We incorporate a vapor barrier at the wall penetration to prevent condensation in the envelope.
4) Electricity and communication
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Dedicated power supply according to the intensity of the chosen model, circuit breaker calibrated on the panel.
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Protected communication cable in the same conduit for uniform aesthetics and reduced service points .
Sizing: Don't get the BTUs wrong
An oversized unit cycles too often and dries out the air; an undersized unit struggles in heat waves and frosts in extreme cold. Our methodology:
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Calculation of loads (exposure, insulation, air volume of the staircase, frequency of occupancy).
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Check clearances around the head to avoid air recirculation.
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Projection of sound levels in nighttime areas.
Result: a Sharp ZU1 with the correct BTU calibration , which delivers the necessary capacity without overconsumption .
HVAC maintenance: simple and profitable
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Clean filters every 4 to 8 weeks during periods of heavy use.
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Coil washing and pressure checking by an AirGreen technician at least once a year .
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Check the drain before summer to prevent overflows.
Regular maintenance preserves seasonal performance and extends compressor life .
Practical advice for owners in Montreal, Laval, Longueuil, North Shore and South Shore
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In a stairwell installation, avoid obstructing the airflow with high shelves or heavy curtains.
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In winter , use a stable setting ; large variations tire the device.
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In summer , activate automatic speed and swing orientation: the diffusion remains homogeneous in the cage and the bearings.
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For homes with pets or renovation dust, plan for early maintenance in the first year.
What the customer gains
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Even temperature on two levels without overheating a single room.
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Silence in the night zone thanks to modulation.
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Controlled bills : the heat pump covers a large part of annual needs.
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Aesthetics : discreet handling and finishes, respect for existing woodwork.
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Grants : complete administrative support according to the applicable program.
Why entrust your HVAC installation to AirGreen?
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Field experience in Greater Montreal : plexes , townhouses , condos .
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Careful selection of brands: Sharp , Gree , Fujitsu , Midea , etc., only in R-32 / R-454B generations for current performance and better environmental responsibility.
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Installation guarantee and local after-sales service : our team ensures monitoring, optimization of settings and maintenance reminders.
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Transparency : documented sizing, line layout, end-of-site photos, explanation of usage instructions.
Quick FAQ - Questions our customers often ask
Can we mainly heat with this heat pump?
Yes, in a well-insulated envelope typical of renovated plexes, the Sharp ZU1 covers the majority of off-season heating and provides efficient backup in winter. A secondary system can still be useful during peaks below -25°C.
Is the stair installation sufficient to air condition the upper floor?
Yes, with the correct vane orientation and automatic speed, the cold air descends less and cools the upper floor first . If necessary, we offer deflectors to increase the range.
How long does a project like this take?
For a comparable configuration, installation takes one day , including testing and user training.
In summary
This HVAC installation takes advantage of the geometry of the stairwell to efficiently distribute air, summer and winter. The Sharp ZU1 R-32 offers efficiency , silence and precision , while our careful execution (short path, gravity drain , invisible finishes) guarantees comfort and durability . For projects in Montreal , Laval , Longueuil , on the North Shore as well as on the South Shore , our team supports each owner from sizing to subsidies .
Useful keywords : heat pump , wall-mounted heat pump , Sharp ZU1 , HVAC installation , HVAC maintenance , Montreal , Laval , Longueuil , North Shore , South Shore , R-32 , extreme cold , heating , air conditioning , duplex , stairs .
The unit on this job, in figures
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 big day, step by step
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 would it look like 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.
Four mistakes we do not make
Flip each card to see what we do instead.
Your own project, step by step
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.
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.
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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Every house has its constraints. We see them before we install.
The on-site estimate is free and the quote follows within 24 hours.
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).