When critical building systems approach the end of their lifecycle, proactive planning becomes essential to protecting both tenant comfort and long-term asset value.

At Hartland Plaza, AQUILA Commercial’s property management and engineering teams identified a major infrastructure risk before it became an operational issue. The building’s original air handling units, installed when the property was constructed in 1985, were approaching 40 years of service.

Working closely with ownership, our team developed and executed a phased replacement strategy that modernized the building’s HVAC infrastructure while keeping the property fully operational for tenants.

Recognizing the Risk Before Failure

After nearly four decades of operation, the air handling units had exceeded the typical lifecycle for commercial HVAC equipment. Despite their age, the units were still performing at a high level due to consistent maintenance and strong engineering oversight. However, performance alone did not eliminate long-term risk.

By 2018, the engineering team began identifying recurring failures in critical components such as motors and shaft bearings. More importantly, the system’s design created a significant operational vulnerability. Each air handler relied on a single motor, fan, and belt. If any one of those components failed, air service to an entire section of a floor could be lost.

For a multi-tenant office building in Texas, a loss of air conditioning can quickly impact tenant operations and comfort. Our team needed to determine whether extending the life of the equipment was a viable path or if full replacement would better protect the asset long term.

A Strategic Capital Decision

Our engineering team evaluated two potential approaches: refurbishing the existing units or replacing them entirely.

Refurbishment would involve cleaning the equipment, replacing bearings and motors, and repairing corrosion in drain pans and coils. While initial estimates suggested a lower upfront cost, this approach would not address the system’s underlying reliability risks or improve energy efficiency.

After evaluating both options, our team determined that the cost difference between refurbishment and replacement was minimal relative to the long-term benefits. A full system replacement provided a more strategic solution by improving reliability, reducing operational risk, and enhancing overall building performance.

Around the same time, the building was preparing to transition to new ownership. The property management team incorporated the HVAC upgrade into the building’s capital planning during the sale process, ensuring prospective buyers understood the condition of the equipment and accounted for the investment in their underwriting.

Ultimately, ownership committed to a multi-year capital plan to replace all 10 air handling units throughout the building.

Implementing Modern HVAC Technology

Our team identified replacement units that introduced a significant technological advancement over the original system.

Instead of relying on a single large fan and motor, the new system utilizes fan wall technology, consisting of multiple smaller ECM motors operating together. This modular design eliminates the single-point-of-failure risk that existed in the original system. If one fan fails, the remaining fans continue operating, maintaining near-full airflow to the space. In addition, the ECM motors adjust dynamically based on building pressure requirements, improving overall system efficiency.

These upgrades will increase system reliability while reducing long-term energy consumption.

Executing the Upgrade Without Disrupting Tenants

Replacing large mechanical systems in an occupied office building requires careful planning and precise coordination.

Many contractors estimated that installation would require up to 10 days per unit, which would have left tenants without air conditioning during the workweek. This level of disruption could have required rent abatements or other concessions to tenants.

To avoid this disruption, our team prioritized a solution that could be executed within a condensed timeframe.

The team ultimately selected a product manufacturer and installation partner through a competitive evaluation process, prioritizing system performance, reliability, and a single-weekend installation timeline. No other installation team evaluated was able to meet this requirement.

Each installation followed a tightly coordinated schedule.

• Friday: The unit is shut down and drained
• Saturday: Crews remove the existing equipment and assemble the new modular system
• Sunday: Technicians complete startup, testing, and system insulation
• Monday: The unit is fully integrated into the building automation system and operational

By completing the work between business weeks, the team avoided disruption to tenant operations and eliminated the need for costly rent concessions, preserving revenue for ownership.

Solving Complex Building Logistics

The building’s layout introduced additional logistical challenges.

Hartland Plaza does not have a service elevator capable of transporting large mechanical equipment, requiring the team to develop a creative installation strategy. The fourth-floor balcony was utilized as a crane staging area, allowing equipment to be brought into the building and transported through tenant space to reach the mechanical rooms.

During the first installation weekend, our team also replaced the building’s 40-year-old isolation valves. This allowed future air handler replacements to be completed without draining the entire chilled water system, significantly reducing downtime and improving installation efficiency.

These engineering decisions streamlined the installation process and minimized operational disruption.

Results

The new air handling units are designed to provide more than 30 years of service, with an estimated 10-year return on investment.

The upgrades also significantly improve maintenance efficiency. Older motors required specialized equipment and external contractors to replace, while the new ECM motors are lightweight and modular, allowing most repairs to be completed quickly by in-house engineering staff.

Motor replacements that previously required hours of labor can now be completed in approximately 30 to 45 minutes.

Combined with improved automation and airflow control, the new system is expected to reduce energy consumption, improve system performance, and enhance tenant comfort throughout the building.

A Coordinated Team Effort

Projects of this scale require alignment across ownership, property management, engineering, and vendor teams.

From capital planning and underwriting through execution and system integration, each phase of the project required careful coordination and technical expertise.

By combining proactive asset planning with disciplined execution, the AQUILA property management and engineering teams modernized a critical building system. The project maintained uninterrupted tenant operations and avoided costly disruptions that could impact ownership revenue.