How a Simple HVAC Audit Uncovered Massive Energy Losses in a Downtown Montreal Office Tower

When an audit reveals more than expected: the hidden truth behind HVAC performance in a commercial building in the heart of Montreal

In the bustling downtown core of Montreal, office towers rise proudly, welcoming thousands of professionals each day. Yet behind these modern facades, outdated or misconfigured HVAC systems sometimes hide in plain sight. At AirGreen, we recently conducted an HVAC audit in a 12-storey office building located near Boulevard René-Lévesque. What began as a routine check turned into the discovery of critical and costly energy losses—invisible to the naked eye.

A prestigious building, but energy-inefficient

The building’s manager contacted us after noticing an unusual spike in the energy bill for both common areas and private offices. At first glance, the infrastructure appeared well-maintained: modern thermostats, clean ductwork, and a regularly serviced heat pump compressor.

However, upon conducting a deeper investigation through our specialized energy audit, we quickly identified several problems that weren’t immediately visible.

AirGreen’s HVAC audit: our professional methodology

Our certified energy efficiency team carried out a full inspection of all heating, ventilation, and air conditioning (HVAC) systems within the building. This included:

• A thermographic analysis of ducts and heat exchangers.

• A balancing check of airflow rates across zones.

• Readings of equipment performance coefficients (COP) from the heat pump system.

• A 24-month comparative analysis of monthly energy consumption data.

What we uncovered: a combination of underestimated issues

1. Air leaks in the fresh air supply ducts between floors 4 and 6, leading to a loss of more than 25% of heated or cooled air, which forced the systems to overwork.

2. Miscalibrated thermostats: several areas were overheated in winter and overcooled in summer, resulting in excessive cycling.

3. An outdated ERV (Energy Recovery Ventilator) with efficiency dropped to just 60%, far below acceptable standards.

4. A central Lennox heat pump, 14 years old, still using the outdated R-410A refrigerant—much less efficient than newer models using R-454B or R-32.

5. Unbalanced ventilation in open-plan areas, creating stagnant hot zones and poor distribution of fresh air.

Our intervention results and customized recommendations

Following the audit, we submitted a detailed, itemized, and illustrated report outlining specific energy optimization opportunities. Our recommendations included:

• Replacing the central heat pump system with a Bosch BOVA36HDN1M20G, 36,000 BTU, Inverter technology, compatible with R-454B refrigerant.

• Installing new smart thermostats with zoned control.

• Fully sealing the leaking ducts using negative-pressure acrylic lining.

• Upgrading the ERV system to a Fantech VHR 200R EC, known for its high efficiency.

• Full airflow rebalancing by revisiting the internal ductwork system.

Measured impact after 60 days

Two months after partial implementation of our recommendations, the building manager reported:

• An 18% reduction in overall energy consumption.

• A 2°C decrease in average temperatures in overheated zones—without compromising comfort.

• A reduction in daily equipment runtime, extending the lifespan of HVAC components.

Why request an HVAC audit even when no problem is visible?

This example clearly shows how a preventive audit can be highly profitable. Even in the absence of breakdowns, an HVAC system can hide costly inefficiencies. Audits also allow access to government grants such as:

• The Hydro-Québec LogisVert program (up to $5,000 for replacing inefficient HVAC systems).

• Tax credits linked to low-GWP refrigerants (Global Warming Potential).

What’s always included in our HVAC audit

At AirGreen, every comprehensive audit includes:

• Performance analysis of heat pumps, wall-mounted and central air conditioners.

• Inspection of mechanical ventilation systems (ERV/HRV).

• Checks of relative humidity and airflow rates.

• Detection of noise, vibration, abnormal power use.

• A written, detailed report with specific, costed recommendations.

Why choose AirGreen for a commercial HVAC audit in Montreal, Laval, and beyond?

We deliver a multidisciplinary approach, combining refrigeration technicians, HVAC engineers, and grant specialists. We understand the real-world challenges of Montreal’s commercial buildings, whether modern or heritage.

Our promise: identify your energy losses with precision, recommend concrete and tailored solutions, and guide you through every step—from quotation to implementation.

Do you suspect energy waste in your building? It might be time to take action. An HVAC audit by AirGreen could uncover what your bills aren’t telling you.