The Most Common HVAC System Is Also the Least Controlled

Why rooftop units are quietly driving energy waste across Canadian commercial portfolios

Across Canada, millions of packaged rooftop units operate every day on retail buildings, warehouses, light industrial facilities, and commercial plazas.

They are one of the most common HVAC systems in the built environment.

They are also among the least controlled.

For many building owners, rooftop units represent a significant portion of total energy consumption. Yet in most cases, they operate independently, without centralized visibility, coordinated control, or performance optimization.

The result is persistent, always-on energy waste that scales across portfolios.

Where rooftop units dominate

Packaged rooftop units, or RTUs, are widely used across:

• Retail plazas and big box stores

• Shopping centres and strip malls

• Light commercial office buildings

• Warehouses and logistics facilities

• Automotive and dealership spaces

• Restaurants and quick-service locations

  
  

These asset classes represent a large share of Canada’s commercial building stock, particularly in suburban and industrial markets. A single portfolio can include hundreds of RTUs operating across multiple sites.

At scale, even small inefficiencies become financially material.

The thermostat problem

Most RTUs are controlled by simple thermostats.

When space temperature drops below the heating setpoint, the unit turns on to provide heat. When space temperature rises above the cooling setpoint, the unit activates cooling. Once the desired temperature is reached, the unit shuts off.

There is no awareness of occupancy, weather, or system efficiency.

There is no coordination between units.

There is no optimization of when or how the system runs.

“In many cases, rooftop units are operating exactly as they were designed decades ago,” said Josh Lewis, Chief Technical Engineer, NERVA Energy. “The issue is not the equipment. It is the lack of control and visibility.”

This reactive operation creates inefficiencies that persist every day.

Fundamental operational limitations

Because RTUs are typically standalone systems, they lack centralized intelligence.

Operators often have limited visibility into runtime, performance, or scheduling.

Ventilation is typically fixed. In Canada’s climate, this means conditioning outdoor air year-round, heating cold air in winter and cooling hot air in summer regardless of actual occupancy.

Schedules are often conservative or outdated. Units start too early, run too long, or operate during unoccupied periods.

Setpoints are frequently adjusted locally, creating inconsistency across buildings.

RTUs also operate independently, without coordination or demand control, increasing peak electricity exposure.

The financial impact

Individually, a single RTU may not appear significant. Across a portfolio, the impact is substantial.

A multi-site portfolio with 100 or more units can accumulate thousands of hours of unnecessary runtime annually.

Even modest inefficiencies, such as extended schedules or excess ventilation, can increase energy use by 15 -30 percent.

For owners, this translates directly into higher operating costs, reduced NOI, and increased exposure to energy price volatility.

“When inefficiency is repeated across hundreds of rooftop units, it becomes a portfolio-level financial issue,” said Trevor Shaw, Chief Operations Engineer, NERVA Energy.

Why the problem persists

RTUs were designed to be simple and independent.

Historically, there was little incentive to connect or optimize them.

As a result:

• Systems were never integrated into centralized controls

• Performance was not benchmarked across sites

• Operating strategies were rarely revisited

• Equipment was replaced without addressing control limitations

Because each unit operates in isolation, inefficiencies remain hidden.

The opportunity for optimization

Unlike central plants, RTU optimization does not require major capital investment.

The opportunity lies in control and coordination.

Key strategies include:

• Centralized scheduling and runtime management

• Standardized setpoints across portfolios

• Demand-responsive operation• Ventilation optimization

• Performance monitoring and analytics

  
  

These measures reduce runtime, improve consistency, and provide visibility into performance.

The business case for action

Optimizing RTUs delivers measurable benefits:

• Reduced runtime lowers maintenance costs and extends equipment life

• Natural gas reduction supports decarbonization without major retrofit

• Electricity reduction helps mitigate peak pricing exposure

• Improved control enhances tenant comfort and consistency

• Utility incentives can often offset a significant portion of implementation cost

In a market where operating margins are tightening, these benefits are increasingly compelling.

A portfolio strategy, not a maintenance task

Rooftop units are widely deployed, often unmonitored, and highly scalable from a cost perspective.

They represent one of the largest untapped opportunities for operational improvement across Canadian commercial portfolios.

Optimizing RTUs is not about replacing equipment.

It is about operating existing systems more intelligently.

The most common HVAC system in Canada is also one of the least controlled.

For owners who operate at scale, that represents one of the most immediate and controllable opportunities to improve financial performance.

About NERVA Energy

NERVA Energy is a distinguished multidisciplinary engineering firm, renowned for its cutting-edge energy performance solutions. With an elite team composed of seasoned energy engineers, M&E engineers, and seasoned in-house mechanical technicians, NERVA is steadfast in its commitment to delivering turn-key solutions. These solutions not only amplify building energy efficiency but are also backed by a steadfast financial performance guarantee.

To learn more about the company and our services, visit:

 www.nervaenergy.com