A raised installation to protect the outdoor unit without cluttering the property
This Hitachi airHome 800 wall-mounted heat pump installation in Îles-Laval immediately stands out because of the position of its outdoor unit. Rather than placing the unit on a ground-level slab, we mounted it high on a sturdy wall structure, directly beneath the building’s eave.
This configuration addressed several site-specific needs. The brick façade had a nearby window, the ground-level space had to remain clear, and the outdoor unit had to be protected from the snow accumulations typical of Laval winters. The installation therefore had to be compact, stable, and accessible without compromising airflow around the heat pump.
The result rests on two triangular aluminum brackets, securely anchored in the masonry. Anti-vibration elements are placed between the support rails and the outdoor unit to limit the transmission of vibrations to the building. The electrical conduits are neatly grouped on the right side of the unit, while the front of the fan remains completely unobstructed.
This installation demonstrates that limited space is not necessarily an obstacle. A careful analysis of the structure, clearances, and maintenance requirements often makes it possible to achieve a more durable solution than an improvised ground installation.
Why install a heat pump on wall brackets?
An outdoor wall-mounted heat pump must be able to operate throughout all four seasons. In Îles-Laval, it must cope with rain, snow, freezing temperatures, thaws, humidity, and defrost cycles.
When the unit is placed too close to the ground, several difficulties may arise:
- snow may partially obstruct the heat exchanger;
- ice produced during defrost cycles may accumulate beneath the chassis;
- leaves and debris may block the back of the unit;
- maintenance becomes more difficult;
- the base may shift as a result of freezing and thawing;
- the unit may be struck by a shovel, lawn mower, or other equipment.
The wall-mounted installation keeps the unit well above these obstacles. In the project shown, the unit is located beneath the roof overhang without being enclosed in a confined space. It therefore benefits from some protection against direct precipitation while retaining the space required to draw in and discharge air.
However, the height should never be chosen at random. We must consider future access to the electrical panel, service valves, refrigerant connections, and outdoor coil. A unit installed too high may require additional equipment every time a technician needs to perform HVAC maintenance or a repair.
Anchors Suitable for a Brick Façade
The site photograph clearly shows that the unit is not resting on simple decorative brackets. The triangular supports have several mounting points distributed vertically across the façade.
Brick requires an appropriate mounting method. Before installation, we must examine, among other things:
- the overall condition of the masonry;
- the location of the mortar joints;
- the type of wall behind the siding;
- the weight of the outdoor unit;
- the vibrations generated by the compressor;
- the additional loads caused by wind, freezing rain, and snow.
A heat pump must not be suspended from fragile siding without verification. The strength of the assembly depends as much on the anchors used as on the material into which they are fastened.
In this installation in Îles-Laval, the two vertical supports are spaced apart to distribute the unit’s load. The diagonal braces transfer the weight to the wall and limit flexing of the horizontal rails.
The Role of Vibration-Isolating Pads
Vibration-isolating components installed between the unit and the supports are also used. These parts may seem secondary, but they play an important role when an outdoor unit is mounted near a window or occupied space.
Without adequate mechanical isolation, compressor vibrations can be transmitted to the masonry and become audible indoors. The noise does not necessarily come from the unit itself, but from the building structure, which amplifies a particular frequency.
The pads help to:
- reduce rigid contact between the frame and the rails;
- limit the spread of vibrations;
- reduce structural noise;
- protect the mounting points;
- maintain a more even base beneath the unit.
They must be positioned correctly and tightened enough to stabilize the unit without eliminating their ability to absorb vibrations.
A Carefully Chosen Position Near the Window
The presence of a window to the left of the heat pump required special attention. The outdoor fan expels a large volume of air forward. It was therefore necessary to ensure that no architectural element blocked this airflow or caused the discharged air to recirculate toward the back of the unit.
The clearances around the unit serve several purposes:
- allow the coil to efficiently capture heat from the outdoor air;
- prevent the discharged air from being immediately drawn back in;
- keep access to the service panels;
- limit heat buildup in cooling mode;
- facilitate water drainage during defrosting.
The roof overhang provides useful protection, but it should not be too close to the top of the unit. The soffit must not obstruct heat dissipation or complicate condenser maintenance.
We also took the window opening into account. An improperly positioned unit could prevent normal use of the window, transmit more noise indoors, or direct an uncomfortable airflow toward a passageway.
A discreet and protected electrical finish
On the right side of the outdoor unit, the cables and conduits are grouped compactly. They follow a short route before entering the building.
A professional HVAC installation involves more than simply making the unit work. The electrical routing must also be protected against the weather, movement, and mechanical damage.
We check in particular:
- the voltage required by the model;
- the minimum circuit ampacity;
- the maximum overcurrent protection;
- the conductor size;
- the presence of a suitable disconnect switch;
- the watertightness of the electrical entries;
- the communication cable protection.
For the Hitachi airHome 800 series, the requirements depend on the installed capacity. The 9,000 and 12,000 BTU models have a minimum circuit ampacity of 14 A and a maximum protection rating of 25 A. The 18,000 and 24,000 BTU versions have a minimum circuit ampacity of 20 A and a maximum protection rating of 35 A.
We always use the unit’s nameplate as the final reference. It would be incorrect to automatically select a circuit breaker based solely on the number of BTUs.
The technical advantages of the Hitachi airHome 800 for a home in Laval
The Hitachi airHome 800 is available in capacities ranging from 9,000 to 24,000 BTU/h. The exact capacity must be determined based on the actual floor area served, room layout, insulation, windows, solar exposure, and the building’s heat loss.
The exterior photograph does not allow us to read the nameplate of the installed model with certainty. We therefore avoid assigning a specific capacity based solely on the apparent dimensions of the cabinet. The sizing carried out before installation remains the relevant information.
A heat pump designed to provide heating down to -30 °C
The airHome 800 is a cold-climate heat pump that can operate in heating mode when the outdoor temperature reaches -30 °C. Hitachi also indicates that it maintains 100% heating capacity at -20 °C, depending on the model.
This performance is well suited to the needs of a residence in Îles-Laval, where winter temperatures can change rapidly. During the same week, the unit may need to operate in damp conditions near the freezing point, then continue producing heat during a period of intense cold.
HeatForce technology and adaptive defrosting allow the system to modulate its operation according to the observed conditions. A defrost cycle is initiated when the outdoor coil accumulates enough frost to hinder heat exchange.
During this cycle, it is normal for vapor to appear around the unit. Water may also run out from beneath the chassis. The elevated position used in this project provides sufficient space for this drainage.
Efficiency of up to 26.5 SEER2
Depending on the capacity selected, the lineup offers efficiency of up to 26.5 SEER2, as well as an HSPF2 of 9.7 for Climate Region 5.
The series technical table specifies the performance of each indoor and outdoor combination. It includes the rated capacities, maximum capacities at different temperatures, sound levels, airflow rates, electrical requirements, and piping dimensions.
Depending on their capacity, the models in the lineup can provide:
- between 5,500 and 15,000 BTU/h of maximum heating capacity at -30 °C;
- between 8,500 and 20,000 BTU/h at -25 °C;
- between 12,000 and 25,500 BTU/h at -20 °C;
- between 14,000 and 27,000 BTU/h at -15 °C.
These variations explain why two heat pumps bearing the same series name are not necessarily suitable for the same building. The Hitachi brochure also specifies an operating range for cooling from -20 to approximately 46 °C, a heating range down to -30 °C, and the use of R32 refrigerant for all four capacities in the lineup.
R32 refrigerant and commissioning quality
The Hitachi airHome 800 uses R32 refrigerant. It has a lower global warming potential than R410A, which is used in many older systems.
However, the type of refrigerant does not change the importance of good installation practices. The lines must be cut cleanly, flared precisely, and tightened to the recommended torque.
Before commissioning, we perform, among other things:
- an inspection of the connections;
- a leak-tightness test;
- a vacuum evacuation of the circuit;
- a vacuum hold test;
- opening the service valves;
- a cooling test;
- a heating test;
- validation of indoor drainage;
- a check of the control operation.
The presence of air or moisture in the refrigerant lines can impair performance and shorten the compressor's service life. A quick installation that omits vacuum evacuation does not provide the same operating conditions as a complete commissioning.
FrostWash 3.0 and Mold Guard 2.0
Indoor air quality is one of the distinguishing features of the airHome 800.
The FrostWash 3.0 function uses a multi-step process. The indoor coil is first heated, then cooled until a layer of ice forms. This layer traps some of the dust and contaminants present on the heat exchanger. When it melts, the water carries the impurities to the condensate drain.
The Mold Guard 2.0 system monitors conditions inside the unit when it is turned off. If temperature and humidity become favorable for mold growth, the system can heat the coil to dry it.
These technologies help limit buildup, but they do not replace:
- regular cleaning of the filters;
- inspection of the drain;
- inspection of the fan;
- professional cleaning of the heat exchanger when necessary;
- periodic maintenance of the outdoor unit.
Dust, pet hair, and cooking residue can continue to accumulate in a heat pump, particularly when it operates almost year-round.
PM2.5 activated carbon filter
The indoor unit includes a PM2.5 activated carbon filter and a stainless steel pre-filter. The manufacturer states that the filter can reduce up to 99% of 2.5-micron particles under specific test conditions.
Activated carbon also helps reduce certain odors and volatile organic compounds. This filtration can be beneficial in a home with pets or in an open space where cooking odors spread easily.
However, a wall-mounted heat pump is not a fresh-air supply system. It primarily recirculates indoor air. To control air exchange and humidity throughout the building, a properly sized air exchanger may still be necessary.
airCloud Go, Smart Eco, and SleepSense
The Wi-Fi interface of the airCloud Go app allows the heat pump to be controlled remotely. Occupants can adjust the temperature before returning home, schedule operating periods, and view certain consumption-related information.
The available features include:
- the weekly timer;
- voice control;
- the display of certain error codes;
- FrostWash activation;
- energy cost estimates;
- the Smart-Fence geolocation function.
The Smart Eco mode uses a presence sensor. After approximately twenty minutes without detected movement, the unit may reduce its energy consumption. When someone returns to the room, the system resumes its initial setting.
The SleepSense function adjusts the temperature overnight to limit uncomfortable fluctuations and excessive corrections.
A sound level suitable for installation near a window
The 9,000 and 12,000 BTU versions can operate at levels as low as 30 dB(A) indoors in silent mode. The range's outdoor units have a published maximum sound level of approximately 52 to 55 dB(A), depending on capacity.
In the Îles-Laval project, the proximity of a window made vibration control particularly important. The unit was therefore installed on rigid supports with mechanical isolation elements.
To reduce noise disturbances, we must consider the following simultaneously:
- the unit's sound level;
- the rigidity of the façade;
- the distance from bedrooms;
- the presence of windows;
- the quality of the vibration-damping pads;
- the tightness and alignment of the supports;
- air circulation around the unit.
A quiet heat pump can become bothersome if it is installed on a structure that amplifies its vibrations. Conversely, a well-prepared installation helps the unit maintain quiet operation.
Hitachi airHome 800 warranty and registration
Hitachi documentation presents a standard warranty of seven years on the compressor and five years on parts.
For certain residential installations, online registration provides an extended warranty of ten years on the compressor and ten years on parts, subject to the applicable terms. An enhanced option may also offer coverage of up to twelve years on the compressor, ten years on parts, and ten years on labor when an eligible upgrade is purchased.
We recommend carefully retaining:
- final invoice;
- model and serial numbers;
- proof of registration;
- AHRI certificate;
- warranty terms;
- documents related to financial incentives.
Eligibility for heat pump rebates
The Hitachi airHome 800 series may qualify for various financial assistance programs. However, the amount must never be determined solely based on the heat pump's commercial name.
Validation must be performed using the exact combination of indoor and outdoor model numbers, its AHRI number, and its heating capacity recognized by the program.
Before confirming financial assistance, we verify:
- the installation address;
- the building type;
- the primary heating source;
- the equipment combination;
- the capacity at the reference temperature;
- the rules in effect on the installation date;
- the documents required by the program.
Programs and their criteria may change. Technical documentation, equipment photographs, and the detailed invoice should therefore be kept.
Mistakes to avoid when installing a heat pump high on a wall
Attaching the supports only to fragile cladding
The support must transfer the load to a sufficiently strong structure. The brick, mortar, and rear wall must be assessed before drilling.
Neglecting vibrations
A unit installed near a window can transmit noise indoors if it rests directly on the rails without proper mechanical isolation.
Placing the unit too close to the soffit
The eave provides protection, but insufficient clearance can hinder maintenance and airflow.
Making the service valves inaccessible
The refrigerant connections and panels must remain accessible. A properly installed unit must also be serviceable.
Forgetting about defrost water
The water produced in winter must be able to fall and move away from the wall without creating a problematic buildup of ice.
Choosing capacity solely based on floor area
Floor area is a starting point, not a load calculation. Insulation, the number of floors, exposure, and room layout directly influence the choice of capacity.
An installation representative of our approach in Laval
This project in Îles-Laval brings together several important elements of our work: masonry analysis, positioning beneath an eave, protection against snow, reinforced supports, vibration reduction, and a compact electrical finish.
We apply the same care to installations carried out in Montreal, Laval, Longueuil, on the North Shore and on the South Shore. Choosing a high-performance heat pump remains important, but its durability also depends on the quality of its location and commissioning.
In this installation, the Hitachi airHome 800 is securely elevated, its fan remains unobstructed, and the technical components remain accessible. The heat pump can thus provide summer cooling and contribute to winter heating without occupying ground space near the building.