Turning setback into sustainability:
When a steam absorption chiller was installed at a large Ontario
university, it was meant to be a key component of the institution’s
ambitious energy-saving strategy. The chiller was designed to harness
excess steam from the university’s cogeneration plant to cool five
campus buildings, including laboratories with critical cooling needs.
The goal was clear: reduce energy, improve the overall efficiency of the
cogeneration plant, and help the school meet its sustainability targets.
Long after installation, however, the chiller had failed to meet expectations. Instead of becoming a valuable asset, it malfunctioned, its potential never realized and its promise unfulfilled. Despite several attempts by different contractors to fix the issues, none had succeeded.
The school continued to struggle, accumulating substantial costs
each year as they had to rely on their standard chillers instead of
the intended absorption chiller. With costs mounting and frustration
growing, the school turned to Envari—a trusted partner with a
reputation for its deep technical expertise and ability to solve
complex energy challenges.
When a steam absorption chiller was installed at a large Ontario
university, it was meant to be a key component of the institution’s
ambitious energy-saving strategy. The chiller was designed to harness
excess steam from the university’s cogeneration plant to cool five
campus buildings, including laboratories with critical cooling needs.
The goal was clear: reduce energy, improve the overall efficiency of the
cogeneration plant, and help the school meet its sustainability targets.
Long after installation, however, the chiller had failed to meet expectations. Instead of becoming a valuable asset, it malfunctioned, its potential never realized and its promise unfulfilled. Despite several attempts by different contractors to fix the issues, none had succeeded.
The school continued to struggle, accumulating substantial costs
each year as they had to rely on their standard chillers instead of
the intended absorption chiller. With costs mounting and frustration
growing, the school turned to Envari—a trusted partner with a
reputation for its deep technical expertise and ability to solve
complex energy challenges.
The Complexity of the Challenge
The school knew a lasting solution was necessary, but the path to resolution was far from straightforward. The chiller was part of a much larger and more complex energy system, and the root causes of its failure were not immediately clear. With the chiller sitting dormant for so long, diagnosing the issue seemed like an overwhelming task.
A Holistic Approach
Enter Envari. The team adopted a systematic, big-picture approach to diagnosing the problem.
The Complexity of the Challenge
The school knew a lasting solution was necessary, but the path to resolution was far from straightforward. The chiller was part of a much larger and more complex energy system, and the root causes of its failure were not immediately clear. With the chiller sitting dormant for so long, diagnosing the issue seemed like an overwhelming task.
A Holistic Approach
Enter Envari. The team adopted a systematic, big-picture approach to diagnosing the problem.
Rather than addressing individual components in isolation, they focused on the entire cooling system as an interconnected network. Envari’s experts understood that to resolve the issue, it was essential to consider how all the elements interacted and to look beyond just treating symptoms.
Through this comprehensive diagnostic process, the team reviewed operational data, tested various components, and carefully analyzed how each part of the cooling system contributed to the chiller’s underperformance. In doing so, they identified four key factors hat were severely impacting the chiller’s efficiency.
The first issue was related to the chiller’s vacuum pressure – a feature unique to absorption chillers. Trapped air, a result of incomplete pressure testing, had prevented the system from reaching the necessary vacuum levels, which are critical for the chiller to operate effectively. Without proper vacuum pressure, the chiller could not maintain its cooling performance.
Rather than addressing individual components in isolation, they focused on the entire cooling system as an interconnected network. Envari’s experts understood that to resolve the issue, it was essential to consider how all the elements interacted and to look beyond just treating symptoms.
Through this comprehensive diagnostic process, the team reviewed operational data, tested various components, and carefully analyzed how each part of the cooling system contributed to the chiller’s underperformance. In doing so, they identified four key factors hat were severely impacting the chiller’s efficiency.
The first issue was related to the chiller’s vacuum pressure – a feature unique to absorption chillers. Trapped air, a result of incomplete pressure testing, had prevented the system from reaching the necessary vacuum levels, which are critical for the chiller to operate effectively. Without proper vacuum pressure, the chiller could not maintain its cooling performance.
The second problem lay with the cooling towers, which are integral to the chiller’s function. One of the cooling tower fans was running in reverse, restricting the overall condenser water cooling capacity. This caused the water temperature to fluctuate, making it impossible for the chiller to maintain a consistent cooling output.
The third challenge involved superheated steam entering the absorption chiller’s generator at a temperature of over 300°F, exceeding the allowed maximum of 280°F. This excess heat caused a dramatic reduction in the heat exchanger’s efficiency, which in turn led to decreased chiller cooling capacity and unstable operating conditions, including the potential for crystallization. These issues significantly hindered the system’s overall performance.
A fourth challenge arose with the configuration of the chilled water piping, which distributed cooling from the chillers to the buildings. The system was designed in such a way that the absorption chiller could not run reliably alongside the two standard centrifugal chillers. As a result, the chiller plant was unable to meet the peak cooling demand on design days during the summer, causing comfort concerns within the buildings served.
The second problem lay with the cooling towers, which are integral to the chiller’s function. One of the cooling tower fans was running in reverse, restricting the overall condenser water cooling capacity. This caused the water temperature to fluctuate, making it impossible for the chiller to maintain a consistent cooling output.
The third challenge involved superheated steam entering the absorption chiller’s generator at a temperature of over 300°F, exceeding the allowed maximum of 280°F. This excess heat caused a dramatic reduction in the heat exchanger’s efficiency, which in turn led to decreased chiller cooling capacity and unstable operating conditions, including the potential for crystallization. These issues significantly hindered the system’s overall performance.
A fourth challenge arose with the configuration of the chilled water piping, which distributed cooling from the chillers to the buildings. The system was designed in such a way that the absorption chiller could not run reliably alongside the two standard centrifugal chillers. As a result, the chiller plant was unable to meet the peak cooling demand on design days during the summer, causing comfort concerns within the buildings served.
Tailored Solutions
With a thorough understanding of the system’s challenges, Envari’s team proposed a solution that would address each issue while optimizing the entire system.
The first step was to ensure the startup vacuum pressure met the specified requirements after the chiller had been inactive for an extended period. Envari recommended that the operator purge the trapped air, allowing the chiller to achieve the necessary vacuum levels before starting the unit for efficient operation.
Next, the team turned their attention to the cooling towers. They recommended reversing the direction of the malfunctioning cooling tower fan, ensuring that water could flow freely and consistently. This would restore the necessary cooling capacity in the cooling tower, allowing the chiller to perform optimally.
The third step involved optimizing the steam heat exchange process. As part of the optimization, Envari proposed a desuperheater to reduce the temperature of the low-pressure steam (LPS) entering the system from 300°F to below 260°F. This adjustment would improve the steam heat exchanger’s efficiency and enable the chiller to operate at full load capacity with a reduced condenser water cooling demand for the cooling towers, ensuring stable operating conditions and peak efficiency. The team also recommended recommissioning the chiller and integrating it into the university’s Building Automation System (BAS), enabling remote monitoring and control of the absorption chiller system.
As a final step, Envari recommended redesigning the chilled water piping to ensure all three chillers can operate in tandem, effectively meeting the total design cooling capacity requirements.
Tailored Solutions
With a thorough understanding of the system’s challenges, Envari’s team proposed a solution that would address each issue while optimizing the entire system.
The first step was to ensure the startup vacuum pressure met the specified requirements after the chiller had been inactive for an extended period. Envari recommended that the operator purge the trapped air, allowing the chiller to achieve the necessary vacuum levels before starting the unit for efficient operation.
Next, the team turned their attention to the cooling towers. They recommended reversing the direction of the malfunctioning cooling tower fan, ensuring that water could flow freely and consistently. This would restore the necessary cooling capacity in the cooling tower, allowing the chiller to perform optimally.
The third step involved optimizing the steam heat exchange process. As part of the optimization, Envari proposed a desuperheater to reduce the temperature of the low-pressure steam (LPS) entering the system from 300°F to below 260°F. This adjustment would improve the steam heat exchanger’s efficiency and enable the chiller to operate at full load capacity with a reduced condenser water cooling demand for the cooling towers, ensuring stable operating conditions and peak efficiency. The team also recommended recommissioning the chiller and integrating it into the university’s Building Automation System (BAS), enabling remote monitoring and control of the absorption chiller system.
As a final step, Envari recommended redesigning the chilled water piping to ensure all three chillers can operate in tandem, effectively meeting the total design cooling capacity requirements.
Driving Efficiency and Sustainability
Once the proposed measures are implemented, the chiller is expected
to operate at full capacity, efficiently cooling all five buildings, including the critical laboratories. This will drastically reduce the school’s dependence on traditional cooling systems, leading to significant energy savings.
A key outcome of these upgrades is the elimination of excessive annual demand charges, a longstanding financial burden. By optimizing the use of excess steam from the cogeneration plant, the school will fully leverage its existing infrastructure, cutting operating costs while enhancing overall energy efficiency.
From a sustainability standpoint, these improvements will be equally
transformative. The chiller will play a pivotal role in lowering electricity usage and reducing the school’s carbon footprint. With the system operating more efficiently, the school will be better positioned to meet its environmental goals and contribute to a more sustainable future.
Driving Efficiency and Sustainability
Once the proposed measures are implemented, the chiller is expected
to operate at full capacity, efficiently cooling all five buildings, including the critical laboratories. This will drastically reduce the school’s dependence on traditional cooling systems, leading to significant energy savings.
A key outcome of these upgrades is the elimination of excessive annual demand charges, a longstanding financial burden. By optimizing the use of excess steam from the cogeneration plant, the school will fully leverage its existing infrastructure, cutting operating costs while enhancing overall energy efficiency.
From a sustainability standpoint, these improvements will be equally
transformative. The chiller will play a pivotal role in lowering electricity usage and reducing the school’s carbon footprint. With the system operating more efficiently, the school will be better positioned to meet its environmental goals and contribute to a more sustainable future.
The Power of Collaboration
What was once a dormant and inefficient system is poised to become a highly effective asset that will deliver both financial and environmental benefits. The success of this project is a testament to the strong collaboration between the university, the chiller manufacturer, and Envari. While technical expertise played a critical role, it was the collaborative, systems-wide approach that enabled the team to address interconnected challenges and unlock the chiller’s full potential.
The Envari Difference
At Envari, we believe the best solutions stem from a deep understanding of the entire energy system. This project demonstrates how a strategic, holistic approach can turn a dormant system into an efficient, sustainable asset that delivers long-term value.
The Power of Collaboration
What was once a dormant and inefficient system is poised to become a highly effective asset that will deliver both financial and environmental benefits. The success of this project is a testament to the strong collaboration between the university, the chiller manufacturer, and Envari. While technical expertise played a critical role, it was the collaborative, systems-wide approach that enabled the team to address interconnected challenges and unlock the chiller’s full potential.
The Envari Difference
At Envari, we believe the best solutions stem from a deep understanding of the entire energy system. This project demonstrates how a strategic, holistic approach can turn a dormant system into an efficient, sustainable asset that delivers long-term value.
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