Installation of a GREE FreeMatch R-32 MultiZone heat pump in Le Sud-Ouest

Two condensers on a flat roof, raised structure and optimized refrigeration path: an urban construction site designed for four-season reliability, silence and easy access to maintenance.

Context: urban co-ownership, fragmented comfort and roof access

In a condominium building in the Southwest (flat roof, elastomeric membranes, technical access via an interior ladder), the occupants complained of unequal comfort between the units: strong sunlight on the south side, cooler rear rooms, and limited installation constraints on the facade. The union wanted a sustainable HVAC solution, not very visible from the street , capable of covering several areas without multiplying the visible openings.

Our recommendation: a GREE FreeMatch R-32 MultiZone heat pump to serve the main rooms, supplemented by a single-zone R-32 condenser dedicated to a high-load space (glass office). The two machines are grouped on the roof , with a raised structure and short refrigeration paths to the technical columns.

Choice of devices: performance, flexibility and compatibility with extreme cold

We are choosing the FreeMatch R-32 range (2 to 5 zones) for three main reasons:

• Precise inverter modulation and high efficiency with R-32 refrigerant (better volumetric efficiency and lower GWP than R-410A).

• Flexibility of indoor unit combinations (wall heads, consoles, cassettes) which allows you to adapt the air diffusion to each room.

• Reliable cold weather performance typical of recent generations, with optimized defrost management.

The second outdoor unit (single-zone R-32) supplies a space with a high sensitive load (bay windows). This division avoids oversizing and guarantees fine regulation in each zone.

Flat roof installation: structure, clearances and longevity

The roof, made of clear elastomeric membrane , imposes strict rules in order to protect the envelope and maintain air releases from the condensers:

• Aluminum elevation : a modular frame made of anodized profiles supports the main condenser. The height is calculated to remain above winter snow and to facilitate water runoff during defrost cycles.

• Treated wooden bed bases : laid flat on non-slip protective strips, they distribute the loads and prevent punching. Through fixings are prohibited in the active roof area; we respect non-penetration to preserve the membrane warranty.

• Anti-vibration pads under each foot**: they limit structural transmission and solid-borne noise perceived in apartments.

• Suction/discharge clearances : the machines are oriented back to back , each with its own free zone to avoid recycling of hot air in summer and premature frosting in winter.

• Management of defrost condensate : free discharge onto the membrane with deflector to direct flow away from flashings and drains ; natural roof slope respected.

Refrigerated routes and crossings: short, protected, watertight

To reduce pressure losses and simplify maintenance, we have favored refrigeration lines :

• Optimized length thanks to the location close to the technical columns ; each route follows a secure cable path .

• High density insulation (UV sheathing) on ​​liquid and gas, connections tied and protected in a technical conduit from the roof entrance.

• Waterproof penetrations : dedicated sleeves, metal flashings and polyurethane sealing; continuity of the air barrier and vapor barrier maintained.

• Wiring grouped together (power supply, communication, heated drain if required) in UV-stabilized gutters.

This care on the courses guarantees the stability of overheating/undercooling and facilitates any future intervention.

Electricity and compliance: dedicated circuits and local cut-offs

Each condenser has its own dedicated circuit to the main panel (rating according to the nameplate), a suitable circuit breaker and a metal disconnect box installed within easy reach on the roof. The cables are UV-resistant , laid on risers to prevent water stagnation. Grounding and labeling comply with the Canadian Electrical Code and the municipal requirements of Greater Montreal .

Commissioning: deep vacuum, checks and fine adjustments

Our standard procedure includes:

1. Vacuum draw < 500 microns , stabilization and ascent test (micro-leak detection).

2. Electronic detector check on all flared and brazed fittings.

3. Weighing and adjustment of the additional load according to the actual lengths.

4. Measurement of temperature differentials and operating pressures to validate the target enthalpy diagram .

5. Setting of blowing curves and time scenes by zone to limit power demand during peak hours .

Result: quiet operation , long cycles at low RPM and smoothed consumption .

Climate management: snow, wind and sun

A Montreal roof requires planning ahead:

• Snow : The elevation maintains a guard above accumulations; modular snow guards are still provided if vortices make a corner more loaded.

• Wind : the frames are braced and secured according to the site category; the spacing limits aeraulic interactions .

• Sun : the orientation respects the expansion of the lines and the UV protection of the ducts; summer tests confirm controlled discharge temperatures .

Interior diffusion: discreet comfort, independent zones

Inside, the MultiZone FreeMatch R-32 powers two wall-mounted units in the living areas and a compact cassette near the hallway, while the single-zone unit serves the office. Advantages:

• True zoning : each space sets its own instructions and flow rate .

• Silence : Low/Quiet speeds at night, adapted sweep to avoid direct breath.

• Homogeneity : no more 2–3°C differences between opposing facades.

HVAC maintenance: preserving efficiency and acoustic discretion

We offer an annual program including:

• Cleaning and disinfection of evaporators (filters, trays, fins),

• Control of currents , voltage and communications ,

• Inspection of the structure (tightening, pads, bed bases, gutters),

• Checking defrosting flows and sealing of crossings,

• Update scenes (summer/winter, presence/absence) to optimize savings .

Careful maintenance keeps the actual COP close to the nominal values ​​and extends the service life .

Key design points to remember for flat roofs (Montreal, Laval, Longueuil, North Shore, South Shore)

• Raise the condensers: snow clearance, defrost drain, maintenance access .

• No drilling into the active surface of the membrane; favor weighted supports and protected paths .

• Move machines apart to avoid air recycling .

• Short refrigerated paths , UV insulated, sealed crossings.

• Dedicated electrical circuits with proximity disconnection .

• Zoning adapted to the actual use of the occupants.

Grants and Eligibility

Recent R-32 heat pumps with high efficiency and good performance in extreme cold may be eligible for Quebec programs. We support customers to document the criteria (capacity at –25/–30 °C, seasonal performance indices) and maximize the assistance available in Montreal , Laval , Longueuil , North Shore and South Shore .

Conclusion: aesthetics, robustness and four-season comfort

• Urban discretion : nothing on the facade, everything is on the roof, clean and accessible .

• Robustness : aluminum chassis, anti-vibration pads, protected paths.

• Controlled comfort : MultiZone FreeMatch R-32 + dedicated single zone = fine regulation without overconsumption.

Are you planning a flat roof project? We size, raise, secure and commission your heat pumps with the same high standards, for a durable , quiet and easy-to-maintain result.