Installation of an Ameristar central heat pump on a flat roof in Saint-Laurent
Installation of an Ameristar central heat pump on a flat roof in Saint-Laurent by AirGreen: comfort, energy efficiency and HVAC expertise throughout 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.
It captures or rejects heat outside. It sits on a level base, above the snow, with free space all around.
The insulated refrigerant lines enter the house through a sealed opening and run to the indoor coil.
A shut-off switch near the outdoor unit isolates it safely for service.
Sitting on the indoor module, it moves heat between the house air and the refrigerant.
Electric furnace or air handler: its fan pushes air through the ducts. The electric backup takes over in extreme cold.
Supply ducts bring air to the rooms; returns bring it back to the unit. Their condition matters as much as the unit's.
It protects the coil and the fan. A dirty filter cuts airflow, so it gets checked regularly.
It runs the heat pump and the backup heat. It must be compatible with the installed system.
An effective solution to optimize comfort and energy efficiency
At AirGreen , we understand that every HVAC installation project has its own unique requirements. In this case, our technicians visited a commercial building in Saint-Laurent to install an Ameristar central heat pump on a flat roof. This type of setup requires not only precision, but also careful planning to ensure the unit's long-term performance and safety.
Why choose an Ameristar central heat pump?
The Ameristar brand , renowned for its reliability and affordability, offers models perfectly suited to the needs of small businesses and multi-unit residential buildings. This central heat pump offers:
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Four-season heating and air conditioning capacity ,
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Compatibility with existing conduits , limiting invasive work,
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Energy efficiency in line with current standards , allowing access to certain subsidies,
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Robust construction , ideal for outdoor installation on flat roofs.
The technical challenges of a flat roof installation
Installing a central heat pump on a flat roof, as is the case in several buildings in Saint-Laurent and Greater Montreal, involves several considerations:
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Stable and elevated support
To avoid direct contact with the roof membrane, the device was fixed to a solidly anchored metal structure resting on treated wooden soles. This arrangement ensures good weight distribution and prevents infiltration. -
Route of refrigerant and electrical conduits
The connections were carefully insulated and bundled, then routed to the interior via a waterproof penetration through the roof. Particular care was taken with sealing to prevent any water infiltration. -
Drainage and condensation management
The elevated positioning allows gravity flow of condensates, which reduces maintenance requirements and limits the risk of freezing in winter. -
Montreal weather conditions
On an exposed flat roof, the unit must withstand heavy snow accumulation and high winds. Our technicians have therefore provided sufficient clearance around the unit and optimal orientation to ensure air circulation even in the middle of winter.
A facility designed for sustainability
The AirGreen team carried out a complete commissioning of the central heat pump: pressure testing, vacuuming, adding refrigerant if necessary, and then calibrating the system. Customers benefit from:
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Stable interior comfort all year round,
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A significant reduction in energy consumption ,
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A robust and easy-to-maintain system , thanks to the quality of the equipment and the know-how of our technicians.
Benefits for building owners and managers
Choosing a professional HVAC installation on a flat roof in Saint-Laurent offers several benefits:
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Optimization of interior space , because the equipment remains entirely on the roof,
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Reduction of ambient noise , the machine being away from living areas,
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Easy access for maintenance , our technicians can work directly on the roof without disturbing the occupants,
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Possible eligibility for financial assistance programs such as LogisVert or certain energy credits, depending on the model and performance.
Conclusion
This installation perfectly illustrates AirGreen's ability to meet the technical challenges specific to buildings in Greater Montreal. By choosing an Ameristar central heat pump for this project in Saint-Laurent , we guaranteed a high-performance, durable system perfectly adapted to local climate realities.
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 ducts, the current indoor module, the electrical panel and the planned spot for the outdoor unit.
The equipment combination, capacity and price, in writing. We check whether the combination qualifies for assistance programs.
Access protected, old unit disconnected and removed when it is being replaced.
Electric furnace or air handler, with its coil, connected to the supply and return ducts.
On a level base, raised above the snow, with free space all around.
Insulated, they enter through a sealed opening and run to the indoor coil.
Dedicated circuits, accessible disconnect, a thermostat that works with the heat pump and the backup heat.
Leak test, vacuum, start-up, airflow check and a test of both modes.
Filter, thermostat, backup heat in extreme cold: what to know before winter.
- The on-site estimateWe look at the ducts, the current indoor module, the electrical panel and the planned spot for the outdoor unit.
- The quoteThe equipment combination, capacity and price, in writing. We check whether the combination qualifies for assistance programs.
- Getting readyAccess protected, old unit disconnected and removed when it is being replaced.
- The indoor moduleElectric furnace or air handler, with its coil, connected to the supply and return ducts.
- The outdoor unitOn a level base, raised above the snow, with free space all around.
- The refrigerant linesInsulated, they enter through a sealed opening and run to the indoor coil.
- Electrical and thermostatDedicated circuits, accessible disconnect, a thermostat that works with the heat pump and the backup heat.
- Tests and start-upLeak test, vacuum, start-up, airflow check and a test of both modes.
- The walkthroughFilter, thermostat, backup heat in extreme cold: what to know before winter.
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.
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.
- Check the indoor module's filter.
- Clear winter debris from the outdoor unit.
- Test cooling before the heat arrives.
- Check the filter more often in peak season.
- Keep registers and returns clear.
- Watch condensate drainage near the coil.
- Change or clean the filter.
- Test heating and backup heat before the cold.
- Book periodic maintenance.
- Clear snow around the outdoor unit.
- Store nothing in front of the indoor module.
- Note any unusual noise or smell and call us.
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. A central heat pump uses the house's ducts.
It connects to the existing ducts to heat and cool everywhere.
2. In extreme cold, electric backup heat can take over.
The indoor module (furnace or air handler) works with the heat pump and takes over in extreme cold.
3. The filter only gets changed when the unit breaks down.
A dirty filter cuts airflow. It gets checked regularly.
4. You can reuse the old unit's size without checking.
The house may have changed: insulation, windows, added rooms. Capacity is confirmed on site.
0 / 4 right answers
What people ask us about this kind of work
Can I keep my current ducts?
What happens in extreme cold?
Furnace, air handler, ducted: what is the difference?
Are there grants?
Do I need a permit?
How much can I save?
How is the LogisVert assistance calculated?
Will my current thermostat work?
Central or wall units: which one?
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).