Modernizing Obsolete HVAC Systems Without Rebuilding
Building Background
A 240-suite condominium complex in Ottawa relied on its original 1976–1977 fan coil units for cooling well into 2019. While most HVAC equipment is designed for a 15 to 20-year service life, these units operated for more than 40 years. By 2019, they had not just aged. They had become a liability.
Fan coil units condition indoor spaces by using water as the energy transfer medium. Hot or chilled water circulates through a hydronic fin-tube coil inside the unit, while a fan moves air across the coil. As the air passes over the coil, heat is either absorbed or released, and the conditioned air is then distributed back into the living space.
At Laurier, the system was designed for cooling only, with electric baseboard heaters providing winter heating. Each suite contains one or two fan coil units connected to the building’s central cooling loop, activated in spring and shut down in fall.
The Problem:
Aging Equipment
and Active Failures
As the fan coil units deteriorated, failures became increasingly disruptive. Corroded metal drain pans developed leaks, causing water damage below.
Spot repairs were no longer viable. The building needed a long-term solution.
The Challenge:
Built Into the Structure
The original fan coils were fully integrated into the building’s walls and structure. Additionally, standard modern units are larger and differently configured.
Replacing them conventionally would have required structural modifications, drywall reconstruction, painting, and extended suite downtime. That approach would dramatically increase costs and disrupt residents for weeks.
The challenge was providing much-needed modernization without demolition.
The Strategy:
A Precision Retrofit
DILFO HVAC was engaged to engineer a practical, cost-effective replacement strategy. Collaborating with O’Dell HVAC, Longhill Energy, and Aurum Manufacturing, the team developed a solution to retrofit new fan coil units custom-manufactured to fit precisely within the existing wall cavities.
DILFO rebuilt the system from within at a fraction of the cost and disruption of a full rebuild.
The Solution:
High-Efficiency,
Future-Ready Units
The selected Aurum fan coils delivered modern performance inside the original footprint.
Each unit included:
- EC (electronically commutated) fan motors for significantly reduced energy consumption and precise airflow control
- Stainless steel drain pans to eliminate corrosion risk
- High-performance control valves and actuators for accurate water regulation
- Compatibility with both chilled and hot water systems
The new configuration allows for a seamless shift from electric baseboards to centralized boiler heating.
DILFO delivered more than a replacement; we provided a high-efficiency strategic upgrade.
Installation:
Efficient, Controlled,
Resident-Focused
DILFO began with test installations in two suites. After documenting performance and confirming fit and finish, the condominium board approved the full retrofit.
DILFO conducted a detailed building-wide audit and developed a suite-by-suite execution plan. To avoid drywall repair and painting, the team provided exact dimensions for custom access doors fabricated to match the existing enclosures.
Technicians removed each old unit, replaced degraded fiberglass insulation with durable foam insulation, and installed the new fan coil within a single day per suite.
Minimal disruption. No structural reconstruction. Immediate performance improvement.
The
Outcome
This project demonstrates how aging mechanical systems can be modernized without invasive construction.
DILFO replaced failing, obsolete equipment with state-of-the-art, high-efficiency technology while preserving the building structure, controlling costs, and minimizing disruption for hundreds of residents.
Retrofitting outdated mechanical systems requires technical precision, product knowledge, and strategic planning. With the right approach, even 40-year-old infrastructure can be transformed into a future-ready mechanical system.
This is modernization done right.
Controls
and Energy Performance
Each suite received a programmable thermostat designed specifically for fan coil systems. Residents can now implement temperature setbacks during unoccupied periods, directly reducing energy consumption and operating costs.
Combined with ECM motors and improved airflow control, the system delivers measurable efficiency gains over the original 1970s equipment.
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Ottawa, ON
1481 Cyrville Road
Ottawa, ON K1B 3L7
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