For building owners and facility managers, reducing energy consumption means increasing value. A prioritized management strategy to increase energy efficiency and refined capital plans that move from no-cost to major capital expenditures can help commercial and institutional facilities managers achieve energy goals. An ASHRAE Level 1 Energy Audit is a great place to start.
Level 1 energy audits have been used for years to identify lower cost strategies that in many cases can be completed with available staff. Terracon typically performs this style of audit at the outset of Retro-Commissioning (RCx) projects, which assess and develops plans to enhance the operation of energy consuming systems for existing buildings that have previously not been commissioned or have not commissioned since original construction. The results of the audit allow the engineering team to target specific building systems for Retro-Commissioning or re-Commissioning.
A Professional Mechanical Energy Consultant brings the right experience on costing and savings to conduct the audit and refine the plan. A Level 1 audit also can be run in parallel with the Energy Star labeling program if desired. If the Level 1 indicates a need for higher capital expenditures, output from the audit would then feed into Level 2 or Level 3 investment grade audits for large capital expenditures. Using the ASHRAE energy audit offers a stepped process to help owners achieve their improvement plan goals.
Level 1 Audit: Steps and Metrics
An ASHRAE Level 1 Energy Audit typically includes these steps:
The audit also identifies and provides a savings and cost analysis of energy conserving measures, and provides a listing of potential capital improvements that merit further consideration and opinions on potential installed costs and energy savings.
Following analysis of utility usage and costs, the audit determines an annual Energy Utilization Index (EUI) and Energy Cost Index (ECI) for the building. The EUI depicts the total annual energy consumption per square foot, and is expressed in British Thermal Units (Btus). Reviewing energy records from the building indicate whether the annual Btu usage is within the typical range of buildings of similar age, size, and physical location in a given geographic area.
Audit in action
The National City Tower in downtown Louisville, Ky., is a 38-story office building, constructed in 1972, containing approximately 871,507 gross square feet (SF). The tower’s engineering staff had previously improved energy usage through various strategies; however, in 2011 the owner desired further improvements to boost the building’s cost competitiveness and increase its overall value. Terracon was selected to help develop a strategy to address feasibility, installed cost, payback, and rate of return, starting with performing a Level 1 Energy Audit to assess the current efficiency of the tower’s envelope, elevator, mechanical, electrical, and lighting systems.
Through the energy audit, Terracon’s mechanical engineers developed 10- opportunities for ECRMs, estimated the installed costs, and estimated their payback and rates of return. The ECRMs included: installing premium efficiency motors on pumps and air handling units; re-commissioning the HVAC system; installing heat recovery equipment, high-efficiency burners at the boilers, and variable speed drives at the chillers; completing a lighting retrofit; and retrofitting the perimeter induction units. The estimated savings were considered incremental and exclusive as individual ECRMs are completed.
The team also identified additional opportunities for further energy reduction. These included installing digital controls and variable speed drives on the remaining elevators; converting the HVAC systems to variable air volume systems; installing a high-performance coating on the remaining exterior glass; and installing a high-efficiency cooling tower. Due to the potential installed cost and complexity of estimating energy savings with these options, Terracon recommended that the owner undertake further analysis, such as an ASHRAE Level 2 or 3 energy audit, to support long-term capital improvement planning.
Immediate benefits, long-term value
A Level 1 Energy Audit provides owners and institutions with a prioritized list of ECRMs that can be implemented during general maintenance activities and make an immediate positive impact on energy costs. Other larger or more capital-intensive measures identified during the audit may be implemented within existing capital improvement budgets to produce more significant reductions in energy costs. A Level 1 audit also can be used to develop to long-term plan for upgrading a facility’s energy-consuming systems requiring future capital appropriations. An ASHRAE Level I Energy Audit is a powerful tool for all facility managers to help achieve immediate gains in efficiency while also supporting their long-term energy improvement agenda.
A version of this article originally appeared in the January/February 2015 issue of Facilities Manager magazine.