HSBC Tower Nets $150,000 in Annual Utility Savings Through Building Improvement
By Dino Giarrusso, Controls and Service, Solutions Leader, Trane Canada
Prince George–based property management firm Majestic Management takes pride in offering customers a high level of real estate experience and multidisciplinary technical skills among its 20-person staff. Their goal is to modernize several buildings in its portfolio to high-performance standards, with a focus on energy efficiency, building performance and comfort.
Included in their portfolio is the HSBC Tower, which is one of the premier office locations in Prince George, British Columbia. As the original heating, ventilation and air-conditioning (HVAC) equipment in the building approached the 40-year-old mark there were increasing challenges with energy efficiency and occupant comfort, and Majestic Management wanted to find solutions to reduce operational costs and make the building more efficient to maintain.
“Occupant comfort has to come first, but energy efficiency and low carbon footprints are also important for many of our tenants,” said Bob Hillhouse, president of Majestic Management.
Challenges of efficiency and comfort
Improving the energy efficiency of the HSBC Tower was a key concern, and issues of occupant comfort in the building were also critical, since Majestic staff spent significant time addressing hot and cold calls. Given the building’s aging equipment, property staff struggled to keep tenants comfortable and were unable to provide the simultaneous heating and cooling they desired in varying areas of the building.
This meant many of the building systems needed to be upgraded or replaced to help reduce energy costs and provide the necessary level of occupant comfort — while also adding asset value to the building and eliminating the risk of catastrophic equipment failure.
Majestic Management sought to convert the building’s antiquated equipment — including the induction fan, chiller and boiler — into reliable, energy-efficient systems and modernize the building’s zoning and ventilation to provide zoned capabilities and the comfort levels expected in a contemporary office space.
Because the 10-story building was fully occupied, upgrades needed to be completed during the shoulder seasons to take advantage of milder weather and to minimize disruption to business operations.
A range of efficient solutions
To find the right solutions, Majestic Management consulted with longtime partner Trane, which has worked with the company for nearly 40 years on engineering design, equipment and building services.
With conceptual input from Hillhouse, who also holds a B.Math degree in computer science with electrical engineering electives, numerous options were discussed. A turnkey design/build solution was developed to help enable building systems to perform as intended to answer long-term efficiency and comfort goals. A design/build process offered several benefits for the project, including faster design and execution time, lower cost to the building owner, less disruption to tenants, and a single source of responsibility via one project partner.
“Energy efficiency was of key importance, but so was our payback. Given that the building equipment was 40 years old and in need of replacement, we could either choose to replace the equipment like-for-like as it failed or do something out of the box,” Hillhouse said. “Trane helped us think outside the box, and in the end, it wasn’t that much more of an investment to have a highly efficient system.”
The two-phased project included not only the replacement of aging air handling units, chillers, boilers and building controls, but also implementation of a system redesign and energy-saving strategies from the Trane Building Advantage™ portfolio of products and services. Each phase took about 18 months from design to completion.
To improve comfort, a dedicated heat recovery chiller and water-cooled screw chiller were installed to match the capacity of the existing centrifugal chiller. The two-chiller combination enables simultaneous heating and cooling to better control temperatures and create zones within the building to satisfy individual comfort preferences. This provides much tighter zone control over temperatures. The two new chillers also operate efficiently to help reduce energy consumption.
In addition, the building ventilation system was modernized with the installation of new air handlers with dynamic air filtration.
The redesigned HVAC system also included additional energy-saving strategies and equipment, such as:
- The cooling towers were reworked to include a free cooling option.
- Boiler piping was revised and boilers were replaced with low-temperature condensing boilers to reduce gas consumption.
- Variable frequency drives were included on the new boilers and on other equipment to reduce fan, gas, and electrical energy use and operational costs.
- Induction box operation was also modified to allow switching between warm water, cool air and cold water warm air. The improvements to the induction boxes allowed boiler temperatures to be lowered to 35 degrees Celsius versus the previous 60 to 70 degrees Celsius, allowing the heat recovery chiller to take care of most of the daily heating requirements. Boilers generally don’t start until source temperatures to the heat recovery chiller are no longer favorable.
Collectively, the new equipment and system upgrades provided energy consumption reductions by improving north, east and south zoning that allowed for much better temperature control in the building.
Heat recovery was one of the technologies that Majestic Management officials were excited to implement in the HSBC Tower. The building’s new heat recovery chiller system utilizes heat recovery, which provides additional efficiency. In this system, recovered energy is used in various ways inside the building, so the system only expels the remaining heat that is not needed.
The dedicated heat recovery chiller recovers and reuses return air heat, eliminating the need to use boilers during shoulder seasons and when the building is occupied through the majority of the winter months. When outdoor temperatures rise, the water-cooled screw chiller works with the dedicated heat recovery chiller to satisfy the cooling load.
Water from the heat recovery chiller is used for all building perimeter heating. This transfer of energy helps to make the building even more efficient; the building is about 240 kilowatts away from being completely self-balanced, meaning it can reject as much energy as the building requires for operation. As a result, there is little to no need for heating and cooling requirements that use new energy.
Significant utility savings
With the improvements, every perimeter office is now a separate zone in the building, which helps maintain better temperature control and satisfy comfort needs and preferences.
In addition, energy costs have decreased by more than 50 percent since the solutions were implemented — with savings of more than $100,000 annually in electricity costs and about $50,000 annually in gas costs. The project was also awarded energy incentives of $100,000 and another $100,000 in tax incentives.
With Majestic Management, Trane, project engineers, contractors and suppliers working as an integrated team on the project, the implemented solutions at the HSBC Tower have helped significantly improve tenant comfort, drastically reduce energy costs and lower operational life- cycle costs.
Improvement efforts continue in the building — with performance, efficiency and comfort as ongoing priorities.
Another high-efficiency solution used in the HSBC Tower project is condensing boilers, which are water heaters fueled by natural gas.
Condensing boilers achieve high efficiency — typically up to 99 percent — by condensing the water vapor in exhaust gases and then recovering the latent heat of vaporization, which would otherwise be wasted. This condensed vapor leaves the system in liquid form.
Condensing boilers are ideal in an application such as this, where they utilize low fluid temperatures and work in conjunction with heat recovery chillers to provide space comfort.
Aiming for Net zero
Majestic Management President Bob Hillhouse wants to turn the HSBC Tower into a net zero building with respect to heating and cooling with improvements and system upgrades. Some of the energy-saving strategies employed in the building include:
- Maintaining building temperatures using low-temperature heat (90 to 130 degrees Fahrenheit) versus heat of 140 to 160 degrees Fahrenheit.
- The building captures waste energy and lifts it with a Multistack dedicated heat recovery chiller to heat the building.
- The building automation system (BAS) has been upgraded and optimized to effectively use the minimal amount of heat from the gas boilers.
- Property managers are considering replacing the high-temperature (180 degrees Fahrenheit) fin-style radiation on the main floor with new low-temperature (125 degrees Fahrenheit) perimeter fan coils.
“We’ve been quite happy with the solutions Trane provided,” Hillhouse said. “We’ve had huge improvements in energy efficiency. In fact, we’ve been advised that this building ranks within the top 10 most energy-efficient buildings in Canada for this climatic region.”