Tag Archives: retro-commissining

Existing Building Energy Consumption: Current Situations, Trends, Legislature and Solutions (Series Post #8: Real World Application, Case Study)

After all this talk about how great energy audits and retro-commissioning is, let’s take a look at a case study which shows the power of these tools in action. We worked on a historic 555,000 sf museum, originally built in 1897. After an energy audit and retro-commissioning study, the facility will save approximately $520,000 in annual energy savings with a simple payback of a little over 2 years.

Major energy conservation measures (ECMs) that were found in the energy auditing process include: retrofitting gallery light fixtures from incandescent and halogen to CFL/LED lamps, upgrading the old pneumatic controls to direct digital controls (DDC) for AHUs and implementing several control strategy upgrades, such as gallery VFD speed optimization, economizer controls and demand control ventilation.

Through the retro-commissioning process, HEA determined several key retro-commissioning measures (RCMs). A selection of issues found include: non-functioning hand-off-auto switches, inactive BMS points, improperly wired supply and return fans, leaking cooling and heating coils, faulty smoke detectors and AHU steam valve leaks. Testing, adjusting and balancing (TAB) for all air and water systems, setting up an AHU BMS scheduling program and the partial free cooling in the chilled water system were key low to no cost RCMs that were identified.

Major operations and maintenance measures (OMMs) include a steam trap survey, boiler tune-up and cleaning and AHU temperature and humidity sensor calibration.

These results prove that proper energy audits and retro-commissioning services can help significantly reduce energy usage in existing buildings. In some cases, repairing or replacing equipment may not be the best fiscal decision based on ROI. The key is to implement the ECMs that make sense for your facility; both operationally and fiscally. Make sure your provider has the proper understanding to prioritize and recommend the best path for the future of your facility.

Thank you for reading my series about existing building energy consumption. Please feel free to ask me any questions and/or leave a comment below.

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Filed under Building efficiency, commissioning, Energy, energy audit, energy consumption, energy efficiency, energy usage