HITACHI airHome Multi 3-Head Wall-Mounted Heat Pump | 42,000 BTU Compressor

• BROCHURE FRANÇAIS
• BROCHURE ENGLISH

• WiFi: Optional
• Warranty (Compressor - Parts - Labor): 10-10-0 years
• Additional Warranty (10-10-10): Possible
• Voltage: 220 V
• Sound Pressure Level (Outdoor): 58.0 dB(A)

A multi-zone system designed for winters here, without compromising on comfort and air quality
At AirGreen, we install wall-mounted heat pumps that must perform at all times in Greater Montreal . The HITACHI airHome Multi with 42,000 BTU compressor (outdoor model RAM-G42N5HAA ) is for homeowners who want to cool and heat three separate zones – today – while keeping the door open for future additions (up to 5 zones). The result: a flexible, energy-efficient and sustainable HVAC system, adapted to the realities of Laval , Longueuil , North Shore and South Shore .

Why this model stands out (and who it's ideal for)
We recommend this configuration for 2-3 bedroom condos and townhouses where you want to cover, for example, an open-concept living room/kitchen + master bedroom + office . The 42,000 BTU capacity provides a comfortable margin for summer heat spikes and dry January cold, while maintaining excellent seasonal efficiency (up to SEER2 23.0 ; HSPF2 up to 7.85 depending on the region). The system maintains continuous heating down to -20 °C , a relevant threshold for Montreal's climate.

Smart HVAC Installation: Our On-the-Job Approach

• Room-by-room sizing: we balance the selection of heads ( 7k, 9k, 12k, 18k, 24k BTU ) according to the actual loads (surface, insulation, orientation, glazing), to avoid oversizing (noise, short cycles) as well as undersizing (lack of heating in very cold weather).

• Multi-zone capacity distribution: In both heating and cooling, the compressor power is shared between the active heads. We prioritize critical rooms (e.g., open areas) and calibrate airflows so that each receives the share it needs when everything is running simultaneously.

• Electricity & protections: the RAM-G42N5HAA operates on 208-230 V single-phase; for 3 to 5 indoor units, the minimum circuit current ( MCA ) and maximum protection ( MOP ) are 30 A and 50 A respectively. We validate your panel, the cable length and the selectivity of the protections.

• Refrigeration lines: 1/4" liquid connections (5 ports) and mixed gases ( 3/8" ×3 + 1/2" ×2 ) with a total admissible length of up to 262 ft and a total drop of up to 75 ft (42k model). We optimize the routes to limit pressure losses and simplify maintenance.

• Noise levels: The outdoor unit announces 58 dB(A) on high speed; indoors, the airHome 400/650 wall-mounted units drop to 27–29 dB(A) on quiet mode (depending on size). We position the equipment to preserve your peace and quiet and that of the neighborhood.

Two wall options that make a difference in everyday life (to be combined freely)

airHome 400 – the essentials, simple and effective
Perfect for bedrooms and offices where discreet operation and intuitive control are required. PM2.5 filter and FrostWash are standard to maintain a clean heat exchanger and stable airflow throughout the seasons.

airHome 650 – optimized comfort and active savings
Ideal for living areas: presence detector ( Smart Eco/Auto-Off modes) which reduces consumption when the room is empty, integrated R32 leak sensor , FrostWash , PM2.5 filter. Compatible with airCloud Go (Wi-Fi) to program your schedules and monitor your consumption.

Indoor air quality: what we see after installation

• FrostWash : A “freeze-thaw” cycle that sanitizes the internal coil and limits the buildup of contaminants, helping to preserve airflow over time.

• Mold Guard : Automatic drying of approximately 60 minutes after each cooling/dehumidification to reduce odors and the risk of mold .

• PM2.5 and ViroSense S filters : reduction of fine particles and inhibition of biological agents, useful for sensitive people and families.

AirGreen Case Studies (Montreal and surrounding areas)

Renovated triplex, Villeray (Montreal)
Context: main apartment 900 sq ft open plan + two closed bedrooms.
Configuration: 12k (living room/kitchen) + 9k + 9k on 42k compressor.
Result: better coverage in supplemental heating at -18°C , low perceived noise thanks to the positioning of the outdoor unit in a sheltered side aisle. The customer uses airCloud Go to program setbacks at night.

Townhouse, Duvernay (Laval)
Context: cathedral living room + mezzanine, two bedrooms upstairs.
Configuration: 18k (living room) + 9k (mezzanine) + 12k (bedroom) .
Result: uniform temperature between ground floor and upper floor in summer; in winter, we prioritized the 18k zone during very cold weather using a differentiated setpoint strategy (better distribution of shared capacity).

Concrete condo, Longueuil (metro side)
Context: two very glazed facades, significant solar gain.
Configuration: 12k + 12k + 9k with precise adjustment of the shutters to counter occasional overheating.
Result: marked drop in humidity in July/August in targeted dry mode, improved acoustic comfort thanks to adapted fan speeds.

What you need to know before choosing your 3 heads

• Combine sizes wisely: a 9k + 12k + 18k trio covers most residential scenarios. Avoid three large heads if a single room has a high load: this degrades efficiency in mid-season.

• Think airflow : Long, narrow rooms sometimes require specific louver orientation or a 650 model to take advantage of the presence sensor.

• Plan ahead for HVAC maintenance: sufficient clearance in front of the outdoor unit (snow, leaves), clean access to filters, and an annual inspection optimize performance and longevity.

• Prepare the appropriate electrical supply (panel, breaker, wiring) upon submission: we validate the required MOP/MCA of the 42k and coordinate the electrician if necessary.

Frequently Asked Questions – AirGreen Field Version
Is it modular if I add a fourth room later?
Yes. The RAM-G42N5HAA accepts up to 5 indoor units . We leave some "play" in the design (capacity and piping) if a future room is considered.

How does the system behave at -20°C?
The machine heats continuously down to -20°C ; the control prioritizes the zones in demand. We adjust the settings to maintain comfort in the main room and avoid defrost cycles that are too close together.

Is Wi-Fi included?
The airCloud Go control connects via an optional adapter . We configure this during installation if you wish.

Is there any financial assistance?
As of the date indicated on our website, the Provincial Grant (LogisVert): $1,500 applies for this type of heat pump (updated: May 1, 2025 ). We verify eligibility and prepare the necessary documents.

Key technical summary for decision

• Outdoor Compressor : RAM-G42N5HAA , 42,000 BTU (cooling), up to 45,000 BTU (heating rated), R-32 .

• Operating Range : Cooling 14°F to 115°F (-10°C to +46°C); Heating -4°F to 75°F (-20°C to +24°C).

• Efficiency : up to SEER2 23.0 , HSPF2 up to 7.85 ; COP 47°F up to 3.6 depending on combination.

• Internal connections : up to 5 heads possible (we install 3 in this offer), mix & match : airHome 400 , airHome 650 , cassette, floor or ducted.

• Acoustics : exterior 58 dB(A) (high), interior 27–53 dB(A) depending on size and mode.

• Piping : 262 ft cumulative, 75 ft total elevation, inter-unit lengths up to 82 ft – enough to accommodate complex routes.

Common Mistakes to Avoid (and How We Prevent Them)

1. Underestimate the load of the open area : we measure surfaces, heights, glazing and infiltration; if necessary, we use an 18k head rather than a 12k .

2. Overlapping uses (e.g. living room + mezzanine): we set differentiated instructions to stabilize capacity sharing.

3. Line too long without adaptation : we respect the recommended diameters and lengths ; beyond this, performance losses.

4. Outdoor positioning in a snow devil zone: we provide defrost clearance + raised base; a protection kit exists for snow.

Why choose AirGreen?
We are a team of experienced refrigeration engineers, familiar with Montreal buildings (row houses, concrete condos, century-old plexes). Our method: room-by-room load study, transparent final offer (no surprises), clear and planned HVAC maintenance , and assistance with grant programs . We install and commission your system to keep it efficient and energy-efficient—in summer and winter.

Ready to optimize the comfort of three rooms, now and for the long term?
Contact us for a 100% free on-site estimate in Montreal , Laval , Longueuil , North Shore or South Shore . We will design the 9k/12k/18k (or other) combination that best suits your needs, configure airCloud Go controls if desired, and deliver a clean, tested, and documented installation.