A critical observation has emerged from the current operational practices, where heat recovery chillers are found to be running with reduced heating in winter and increased cooling in summer. Contrary to Kaizen analysis findings, it becomes apparent that heat recovery chillers demonstrate superior efficiency in heating during winter compared to boilers, while exhibiting lower efficiency in cooling than the primary chillers during summer. An important consideration arises from this analysis – the operation of heat recovery chillers for heating results in the production of free cooling. This underscores the significance of prioritizing their operation in winter over summer. Aligning with Kaizen principles, this adjustment not only enhances operational efficiency but also capitalizes on the benefits of recovery chillers during periods of low demand in winter.
The current practice of operating large main chillers in winter, despite low load and efficiency concerns, emphasizes the need for a more optimized and seasonally attuned approach to ensure energy efficiency and cost-effectiveness for our client’s building.
To address the identified challenges, we propose an automated heat recovery operation facilitated through the Building Automation System (BAS), eliminating the need for manual intervention from facility management. The revised operational model seeks to optimize the utilization of heat recovery chillers by prioritizing full operation during winter and ceasing operation during summer.
The new operational strategy strategically aligns with the inherent efficiency of heat recovery chillers during winter months, minimizing reliance on less efficient boilers for heating. By maximizing the operation of recovery chillers for heating in winter, the system not only reduces heating costs but also generates ample free cooling. Importantly, this free cooling is substantial enough to entirely replace the need for main chiller operation during winter.
A key advantage of this proposed solution lies in the cost-effectiveness of heating produced by heat recovery chillers. The energy efficiency gains achieved during winter operations, coupled with the free cooling generated, position the system to supply heating needs more economically compared to the current reliance on less efficient boilers.
The implementation of our proposed solution demonstrates significant potential cost savings for our client’s building. By prioritizing the operation of heat recovery chillers for first-stage heating before engaging boilers in winter and as a standby to main chillers for cooling in summer only, when necessary, the estimated annual savings surpass CAD $12,000.
Similarly, optimizing the heat recovery chiller for first-stage cooling before activating chillers in winter, with main chillers on standby for cooling in winter only when required, presents an additional potential saving of over CAD$15,000 per year.
In aggregate, these operational enhancements yield a combined potential saving exceeding CAD$27,000 annually. Beyond the financial benefits, these optimizations translate to a noteworthy reduction in energy consumption, with an estimated 270,000-kWh decrease. This reduction in energy usage corresponds to a substantial environmental impact, equating to a decrease of approximately 220,000 kg of CO2 gas emissions.
Putting this environmental impact into perspective, the 220,000 kg reduction in CO2 emissions is equivalent to preventing the combustion of approximately 302,000 pounds of coal in Canada. This not only underscores the financial prudence of the proposed solution but also emphasizes its positive contribution to environmental sustainability.
