A recent energy audit of a three-story, 84,000-square-foot office building built in the 1980s led to a $32,000 yearly savings for the building's owners. Energy auditor and architect Larry Macias conducted the audit at Corporate Point, a Class A office building in Reno, Nev. After conducting a complete on-site evaluation of the building envelope and electrical and mechanical systems, Macias identified ways to help the building owner save more than $30,000 a year on the energy bill.
The owner's budget didn't allow for major retrofits, so Macias concentrated his efforts on the lighting systems and basic HVAC equipment. His goal was to find ways to reduce the $25,000 monthly electrical bill.
The Energy Audit: A Look at Lighting and Simple HVAC
Macias conducted a complete inventory of the lighting system through all the spaces:
- Light meter readings identified each lighting type and were referenced to electrical consumptions.
- Tenants were interviewed, occupancy schedules were identified, and electrical consumption records were acquired at 15-minute intervals over a three-year period. Weather data was collected at one-hour increments for the same time span.
- An electrical consumption baseline was established for the lighting system only, and electrical consumptions for pumps, motors, fans, etc., were identified.
- Energy codes were reviewed to determine non-compliance levels.
- Economizers and timers were installed in the HVAC systems so that the air conditioning system can utilize free cooling whenever possible.
- A preventative maintenance program was developed to monitor filter change-outs, schedule inspections and update motors and pumps to a more efficient system.
When this first phase is completed, the $25,000 monthly electric bill will drop to $14,000. Corporate Point's owners were surprised with the savings Macias uncovered and have requested a proposal to continue identifying other cost-saving opportunities for future retrofits. Macias suggests that additional savings are available with motion sensors, dimming features, daylight sensors and LED existing lighting. If these additional features were added to the cost-saving measures already in place, Macias estimated that he could reduce electrical costs to around $11,000 a month, making their savings more than half of their current cost.
The Energy Auditor's Role
An energy auditor is more than someone who compiles a list of obvious energy-saving tips. "An energy auditor is someone who analyzes a facility's energy usage history and the facility infrastructure: doors, windows, roofs, insulation, and the facilities' energy usage equipment HVAC systems, lighting systems, water systems, manufacturing processes, computer systems and other energy loads, to determine what energy efficiency measures could be implemented to reduce energy usage," said Greg Smith, a certified energy manager and president of Energy Optimizers USA.
Although there is no industry standard for technical certifications for energy auditors (nor is it required), several organizations provide certification and training, said Michael Byrnes, executive vice president and general manager of SourceOne, which is the consulting division of Veolia Energy North America. Among them are the Association of Energy Engineers (AEE), which provides Certified Energy Auditor (CEA) and Certified Energy Manager (CEM) certifications, and the U.S. Green Building Council, which established the LEED Professional Accreditation (LEED-AP). According to the USGBC website, LEED-APs must demonstrate a thorough understanding of green building practices and principles, as well as a working knowledge of the LEED rating system. In 2008, administration of the Professional Accreditation program transitioned to the Green Building Certification Institute (GBCI).
In addition to these certifications, associations and other organizational affiliations stress the importance of energy efficiency, as do legal certification programs that award the licensed/registered Professional Engineer (PE) and Registered Architects (RA) licenses.
"At Veolia Energy, we have rigorous in-house training for all of our energy auditors and most of them are PEs, LEED-APs or CEMs," said Byrnes, who is a professional engineer and LEED-AP. "Although technical certification is not required in the industry, we believe it is a good way to maximize the overall quality of the audits and to encourage our auditors to have these certificates in addition to our [in-house] training."
What Tools and Software Are Used in the Audit Process?
"When an auditor evaluates a facility, he or she first needs to test the performance of the building as a benchmark or baseline relating to energy, water, carbon, etc.," said Pat Bailey, PE and AEC sustainability senior product manager at Autodesk, a design software company specializing in 2D and 3D design.
There are many modeling tools, both hardware and software, that are utilized to achieve this baseline reading. Energy Optimizers USA recommends using a variety of data loggers to conduct a proper audit: light loggers, temperature and humidity sensors, infrared cameras to detect heat loss, amperage loggers, etc.
For Byrnes, "Common sense is the most important piece of equipment, but there are a number of tools that [Veolia] energy auditors use. For example, we typically utilize handheld temperature sensors that can measure heat loss in air ducts, pipes and insulation. In addition, thermal imaging devices are utilized to get a better picture of a building's overall efficiency, including heat that might be escaping. Finally, we utilize portable light meters that can measure the lighting in a space, as a dull or over-lit space can lead to inefficient energy use," Byrnes said.
The type of project determines which hardware and software modeling tools that Johnson Controls Inc. uses in its auditing process, said Darryll L. Fortune, the company's director of global public relations for building efficiency. This Milwaukee-based company, which manufactures auto parts, building efficiency systems and power solutions for a global market, uses a set of tools to measure energy expenditures:
- Auditors use kW meters, data loggers, BMS systems and other tools to collect data.
- For energy modeling and financial modeling, the company has a number of internal benchmarking/tracking tools that help its engineers analyze the client's utility and operational expenses.
- For overall system performance and benchmarking, Johnson Controls uses standard third-party software programs like eQuest and Metrix to model the building, calculate savings and produce a baseline.
- The company's propriety Solution Architect software tool helps engineers and project managers collect, store and manage audit data.
"These tools along with our engineering experience allow Johnson Controls to work with our clients to help them find the correct solution for their business," Fortune said.
Analyzing the Data and Interpreting the Results
Audit results are modeled as a baseline. A model can range anywhere from a spreadsheet for lighting only to a whole building energy model that is then used to predict the savings that are possible from a retrofit, Byrnes explained. "The savings are often compared to both the pre-existing building and a new building baseline. The owner of the building will save energy, money and carbon relative to the baseline building, but it is sometimes useful to also compare it to a new construction baseline because the new construction baseline is often required by local building departments when a major retrofit occurs," he added.
Veolia Energy serves a wide variety of customers in a number of industries -- hospitals, universities, hotels, mixed-use real estate developments, industrials, government facilities and office buildings. This gives Veolia an extensive database of commercial buildings, Byrnes said. "We use this database to benchmark our results from the audits, which allows us to do comparisons of similar building profiles to determine standard levels of comfort for energy usage, temperature, humidity, light, and so forth. Other resources for benchmarking results would be through government programs such as the DOE/EPA's Energy Star Portfolio Manager."
The Different Auditing Levels
Depending on the needs and budget of the building owner, an audit ranges from a simple overview to a comprehensive work-up. While there are universal basics keep in mind, each auditor is different and it is a good idea to outline expectations and requirements prior to the audit.
- Level I, basic -- This preliminary audit is also referred to as a simple, screening or walk-through audit. This quick audit is the least invasive and involves a building walk-through, minimal interviews with personnel, and a review of the facility's utility bills and operating information. This type of audit will most likely uncover major energy loss problems and will give a rough estimate of how effectively energy is used. While the preliminary audit should not be considered comprehensive, it is a good first step to prioritize projects and decide if a further, more comprehensive audit is needed.
- Level II, intermediate -- This general audit is also called a mini-audit, site energy audit or detailed audit. The intermediate level audit builds on a basic audit by collecting detailed information about facility operations and performing a more extensive evaluation of energy conservation measures. This type of audit will be able to highlight all energy-saving measures appropriate for the building and can be a roadmap for energy efficient retrofits.
- Level III, advanced -- Also known as the investment-grade audit, comprehensive audit, maxi audit, or technical analysis audit, this comprehensive test look at a facility's energy-use characteristics and provides the owners with a reliable estimate of the building's overall efficiency. Modeling software and hardware are used to collect even more detailed data, risks are assessed, and a reliable estimate can be given as to what energy retrofits are needed for capital improvement projects.
How to Find an Auditor
Many companies perform energy audits. Research to find the energy auditor with the proper certification that is best suited to the type and size of the facility. Also, try investigating the local utility website. For example, the Louisville Gas and Electric Company (LG&E) and Kentucky Utilities (KU) make residential and commercial energy audit requests available on their website at http://www.eon-us.com/home.asp.
Here are other websites to help you locate an energy auditor:
www.gbci.org -- This website will help you locate a certified LEED-AP in your area
www.aeecenter.org/certification/ -- The Association of Energy Engineers lists Certified Energy Managers (CEM) on its website.
www.prenova.com/commercial_energy_audit.jsp -- Prenova is an energy services provider based in Atlanta, Ga., that works to source energy and to control energy consumption.
www.veoliaenergyna.com -- Veolia Energy is an international environmental services firm that focuses on improving energy efficiency and reducing carbon footprints.
While it is usually recommended to hire a professional trained and certified in energy auditing, there are several self-guided programs available for lower-level audits, such as http://denbyenergy.com/commercial-energy-audit-training and http://www.nicor.com/en_us/commercial/planning_needs/build