Installation of a HITACHI airHome 800 wall-mounted heat pump in Montreal

An Umbrella Above the Heat Pump: Behind the Scenes of an Installation During a Montreal Heat Wave

At this job site, one detail catches the eye even before the unit itself: a large umbrella, firmly secured above the work area, casts its shade over the red brick façade of a typical Montreal plex. The temperature was hovering around 32 °C, and our technician was finishing the connections for a HITACHI airHome 800 wall-mounted heat pump installed on wall brackets several metres above the ground. The umbrella was not a whim: it kept the brazing area and electronic components protected from direct sunlight, and allowed the installer to work precisely despite the heat. At AirGreen, we often say that the quality of an HVAC installation comes down to details that no technical sheet mentions.

This project perfectly sums up a Montreal summer: brick buildings constructed long before air conditioning, floors that retain heat, and occupants looking for a lasting solution rather than a noisy window air conditioner that must be reinstalled every spring.

The Starting Point: A Plex Floor That Had Become Suffocating

The building is a brick plex like the thousands found throughout Montreal: a sun-drenched façade, a wrought-iron rear balcony, and an alley lined with mature trees. The occupants contacted us after a particularly difficult first heat wave. Fans moved the air without cooling it, nights were becoming uncomfortable, and the portable air conditioner installed as a temporary solution was driving up the electricity bill without ever reaching a comfortable temperature.

Their request included three clear requirements:

• quiet and efficient air conditioning for the warmer months;
• reliable heating capable of handling Quebec winters, in order to reduce dependence on electric baseboard heaters;
• a clean, ductless installation that respects the appearance of the façade and the limited space around the building.

A wall-mounted heat pump was the natural choice. The remaining challenge was choosing the right unit and, above all, successfully completing the installation in a dense urban setting where every square metre matters.

Why the HITACHI airHome 800 Wall-Mounted Heat Pump

The HITACHI airHome 800 line covers capacities from 9,000 to 24,000 BTU/h. For this project, we selected the compact format in the series, whose outdoor unit (approximately 850 x 650 mm) is perfectly suited to wall mounting on a plex. Here is what led to this recommendation.

HeatForce: 100% Heating Capacity at -20 °C

This is the feature that sets the airHome 800 apart in its category. Thanks to HeatForce technology, the unit maintains 100% of its rated heating capacity even when outdoor temperatures reach -20 °C, and it continues heating down to -30 °C. In practical terms, the 12,000 BTU model still delivers 13,500 BTU/h of heating at -20 °C. For a Montreal home, this means consistent warmth in January without the baseboard heaters having to take over automatically. Adaptive defrost technology further enhances performance in freezing-rain conditions, a scenario our winters know well.

Efficiency, Quiet Operation, and R32 Refrigerant

The series offers a seasonal efficiency rating of up to 26.5 TRÈS2 (SEER2) and a heating coefficient of up to 12.0 CPSC2, along with ENERGY STAR certification. In quiet mode, the compact models operate at as little as 30 dB(A) indoors: quieter than a whisper, something the occupants confirmed on the very first night. The Dry mode also removes up to 4.5 litres of moisture per hour, depending on the model, a real advantage during humid July days. Finally, the unit uses R32 refrigerant, which has a low global warming potential and aligns with carbon-emission reduction goals.

Healthier Air Without Complicated Maintenance

The airHome 800 incorporates HITACHI-exclusive self-cleaning technologies:

• FrostWash 3.0 freezes and then melts impurities accumulated on the heat exchanger coil; according to the manufacturer's tests, this process eliminates up to 99% of viruses and bacteria and 95% of mould present on the coil, while also reducing odours.
• Mold Guard 2.0 monitors conditions inside the unit 24 hours a day, even when it is turned off, and automatically dries the coil as soon as conditions favourable to mould growth are detected.
• The PM2.5 activated-carbon filter, combined with a stainless-steel pre-filter, captures 99% of fine particles and helps deodorize the room.
• Outside, DuraSpin reverses the fan direction to expel dust accumulated on the heat exchanger.

For simplified HVAC maintenance between our visits, it is hard to beat.

airCloud Go: Control from Your Phone

Wi-Fi connectivity is integrated and concealed inside the indoor unit. The airCloud Go app lets you control the heat pump from anywhere: weekly scheduling, the Smart-Fence function, which adjusts operation according to your location, energy-cost estimates with budget alerts, and voice control through Amazon Alexa or Google Home. The SleepSense and Smart Eco functions adjust the temperature according to sleep and room occupancy, preventing the home from being air-conditioned while empty.

The Installation Process, Step by Step

1. Site assessment and load calculation. Floor area, insulation, windows, orientation: we size each unit according to the actual home, never by guesswork. An oversized unit costs more to purchase and does a poor job of dehumidifying; an undersized unit works too hard.
2. Choosing the outdoor location. Since floor space was limited, we mounted the outdoor unit up high on sturdy wall brackets anchored into the masonry, above the window head. This position keeps the condenser well above snow accumulation, clears the ground-level passage, and facilitates defrost-water drainage. Anti-vibration pads isolate the structure, preventing any vibration from being transmitted to the brick.
3. Refrigerant piping and drainage. The insulated lines run discreetly along the façade to the indoor unit, with a controlled drainage slope to remove condensate without staining or damage.
4. Code-compliant electrical connection. A dedicated outdoor disconnect was installed within immediate reach of the unit, allowing it to be safely de-energized during future maintenance.
5. Vacuuming and leak testing. Before releasing the R32 refrigerant, the circuit is evacuated and rigorously tested. It was precisely during this phase, under the blazing sun, that the famous umbrella proved most useful.
6. Commissioning and demonstration. Configuring the airCloud Go app and explaining the modes, filters, and simple maintenance steps leaves the customer fully self-sufficient.

The job was completed in a single day, with the ladder folded away and the façade spotless by late afternoon.

The Mistakes We Correct Too Often in Montreal

Our teams regularly take over installations that were completed in haste. The most common pitfalls include:

• Outdoor unit placed on the ground in an area where snow accumulates: repeated defrost cycles and loss of capacity in the middle of January. High wall mounting, as used here, solves the problem in dense neighbourhoods.
• Oversized unit “just to be safe”: short cycles, poor humidity control, and premature compressor wear.
• Poorly insulated or unprotected piping, causing condensation and efficiency losses.
• Model not verified against rebate eligibility lists before purchase: a mistake that can cost thousands of dollars in financial assistance.
• Work entrusted to an installer without an RBQ licence, with the resulting consequences for insurance and compliance.

Rebates: Lowering the Cost with Current Programs

The airHome 800 series is eligible for most provincial heat-pump incentives. Units certified for cold climates—capable of heating efficiently at -25 °C and below—fit exactly the profile sought by programs such as Hydro-Québec's LogisVert. Amounts vary according to the exact model and current program terms; that is why we verify the unit's eligibility before purchase, prepare the required documentation (detailed invoice, model references, photos of the rating plate), and guide our customers through the process in Montreal, Laval, Longueuil, the North Shore, and the South Shore.

AirGreen: Real Installations, Not Catalogue Photos

The photo from this job is not staged: it is our everyday reality. A Montreal family business operating for more than 15 years (RBQ licence 5645-9605-01), AirGreen is an authorized HITACHI dealer and installs wall-mounted heat pumps, wall-mounted air conditioners, and multi-zone systems throughout Greater Montreal every week. Our advisors help you choose the right capacity, our installers attend to every detail—even the umbrella when a heat wave strikes—and our team remains available for HVAC maintenance throughout the seasons.

For a free quote in Montreal, Laval, Longueuil, the North Shore, or the South Shore, call us at (514) 316-2973 or email sales@airgreen.ca. We will assess your home, recommend the most cost-effective configuration, and manage your rebate application from start to finish.