A key project to improve energy efficiency and the reliability of climate comfort
At AirGreen , we recently completed a rooftop HVAC installation project in Longueuil , in an office building requiring an upgrade of its heating and air conditioning system.
Our mandate: to replace an old central compressor with a modern monobloc heat pump in order to improve energy performance, reduce maintenance costs and ensure more precise control of occupant comfort, summer and winter.
Project context and objectives
The building in question, built in the 1980s, presented several challenges typical of older commercial buildings:
-
An outdated air conditioning system at the end of its useful life, generating repeated breakdowns.
-
A flat roof with limited structural capacity , requiring rigorous load calculations.
-
The lack of fine-grained regulation by zone causes significant thermal imbalances between offices facing south and those in the shade.
The client's objective was clear: to replace the obsolete system with a compact, reliable and energy-efficient solution, without disrupting the daily operations of the tenant companies.
Constraints and site preparation
The main constraints were related to:
-
Access to the roof requires coordination with the building's security service and a temporary closure of the parking lot for the lifting of the equipment.
-
Noise and vibration management , taking into account the proximity of workspaces.
-
Compliance with the anchoring and sealing standards dictated by the RBQ and CSA B52 , to avoid any infiltration or localized overloading on the roof.
Before any intervention, our engineers carried out the following:
-
A structural load calculation to validate the compatibility of the roof with the new heat pump.
-
A complete thermal survey to assess heating and cooling needs according to the actual configuration of the spaces.
-
An electrical analysis to confirm the existing power panel's ability to support the new unit.
Technical solution implemented
To meet the client's needs, AirGreen opted for the installation of a Mitsubishi Electric brand commercial heat pump , City Multi monobloc air/air model, mounted on a raised galvanized structure with thermal insulation and anti-vibration pads.
Main features of the installed system:
-
Capacity: 36,000 BTU/h , suitable for the calculated thermal loads of the building.
-
Variable speed inverter technology , allowing precise power adjustment according to actual demand.
-
Coefficient of performance (COP) greater than 4.2 , ensuring substantial energy savings.
-
Reversible operation , guaranteeing both heating and air conditioning with a single device.
-
BMS (Building Management System) compatibility for remote monitoring and control.
The refrigeration lines were sheathed and mechanically protected , while the electrical connections were brought into compliance with CSA C22.1 standards.
Construction progress
The project was carried out in three major stages over a period of 48 hours:
-
Preparation and lockout : safe disconnection of the old compressor, verification of circuits and securing of roof access.
-
Mechanical installation : lifting the new Mitsubishi unit onto the roof using a cherry picker truck, installing supports and connecting refrigeration lines.
-
Commissioning and calibration : pressure tests, verification of airflow rates and configuration of the programmable wall control.
Each step was supervised by a certified AirGreen project manager , ensuring compliance with the lockout plan and electrical and mechanical safety protocols .
Results and Key Performance Indicators (KPIs)
Just a few weeks after implementation, the benefits for the customer were already measurable:
-
28% reduction in overall energy consumption related to heating and air conditioning.
-
Temperature stabilization to ±1 °C throughout the offices, improving employee comfort.
-
40% decrease in service calls compared to the previous season.
-
Improved perceived acoustics in workspaces thanks to anti-vibration mounts and inverter technology.
Preventive maintenance and monitoring of building management systems
AirGreen has integrated this installation into its commercial maintenance program . The contract includes:
-
Semi-annual preventive maintenance visits (cleaning of coils, checking of refrigerant pressures, checking of electrical connections).
-
Remote monitoring of operating parameters (temperature, pressure, efficiency) via building management systems with automatic alerts in case of anomalies.
-
A local stock of critical parts (electronic boards, temperature sensors, start relays) to ensure 24/7 intervention times.
Compliance, safety and certifications
The project complies with all applicable standards and codes:
-
CSA B52 – Code for Mechanical Refrigeration
-
ASHRAE 15 and 62.1 – Indoor Air Safety and Quality
-
Quebec Building Code
-
RBQ, License #5730-3761-01 – Specialized HVAC Contractor
The conduits and supports were inspected by a certified structural engineer before final site approval.
Subsidies and funding
Thanks to its excellent energy efficiency, the installed Mitsubishi heat pump is eligible for Hydro-Québec's EcoPerformance program , which reimburses a significant portion of the costs related to improving the energy efficiency of commercial HVAC systems.
AirGreen took charge of the entire administrative process , including the preparation of the technical report and the submission of supporting documents.
Conclusion
This rooftop installation project perfectly illustrates AirGreen 's ability to offer turnkey commercial HVAC solutions , combining energy performance, reliability and regulatory compliance.
Thanks to a rigorous technical approach and exemplary site management, the client now benefits from a modern, energy-efficient and sustainable system, guaranteeing continuity of operations and optimal comfort for the occupants of their building in Longueuil.