Energy Audits Have a Place in Building Design and Maintenance
Energy conservation as a design principle? It has validity, say professionals who conduct commercial energy audits, advising building owners on how to manage energy consumption wisely and create more comfortable buildings in the process.
New and existing buildings have room for improvement, according to John Fetters of Effective Lighting Solutions in Columbus, Ohio, and Richard Pearson of Pearson Engineering in Madison, Wisconsin.
They agree that the idea of energy conservation has matured to be as much about saving money as saving resources. The United States government now requires measurement and verification of energy efficiency in all existing federal buildings those under construction. Even the World Bank and United Nations have weighed in on what has become a global concern. Whatever the venue, it is clear that a renewed interest in the field has increased the demand for energy audits and the measurable outcomes they produce.
Defensible Result
Sleuthing out the weak points in the grid of systems that light, heat, and cool a building is an apt description for the work of an energy audit. What John Fetters calls "a moving target" and Dick Pearson describes as a problem-solver's challenge has precipitated the demand for sophisticated technology and skills.
The most consequential energy audits are those done by an outside expert to identify problems in any or all of the major systems. Such an audit is essential for identifying the most beneficial changes and establishing a benchmark for future efficiencies. A facility or plant manager may also conduct audits to monitor changes in efficient operation of the lighting and HVAC systems. An important but often overlooked "audit opportunity" is the kind of review that comes before the ribbon-cutting ceremony.
"Really efficient energy use has to be built in from the beginning," says Fetters, an electrical engineer and lighting consultant. He implements lighting surveys and designs energy-efficient lighting for his clients in the commercial, industrial, and government sectors. In existing buildings that have not been audited for energy use, which he estimates at more than 70 percent of commercial buildings in the United States, upgrades are inevitable. "But we can audit a new building and still get results."
Defensible results raise the profile of energy management as a concept that has come of age, notes Pearson. A skilled auditor researches all aspects of energy use in a building, he says, develops an end-use profile, establishes a benchmark, nails down the costs to upgrade, calculates the savings, and then produces the evidence that those savings have occurred. Missing a step wastes energy in more ways than one.
"It is quite a challenge to persuade a building owner to follow your advice after promises of improvement made by a previous auditor did not materialize," Pearson explains. "An auditor must identify realistic modifications and estimate costs and savings thoroughly."
This is a time of transition between old and new, Fetters acknowledges, with lots of retrofitting in between. "Much of our work as consultants is educating. We are training managers and technicians to audit and maintain their existing systems more efficiently."
Another advantage to running a check on energy systems in commercial buildings is the chance to create a better work environment. The experts say it is no secret that productivity is compromised when heating and cooling systems work poorly or lighting is badly designed for the tasks at hand.
Meaningful Standards Guide Design and Auditing
Industry standards for energy-efficient design and construction have been around for 27 years. Standard 90 was first published by ASHRAE (American Society of Heating, Refrigeration and Air-Conditioning Engineers) in 1975. Periodic revisions to Standard 90 redefined efficiency requirements for new construction and remodeling and reflected advances in technology and materials. It is code in many jurisdictions and a meaningful guide for professionals who audit energy use and energy management in commercial or industrial buildings.
Dick Pearson is a member of the ASHRAE committee on energy management responsible for keeping Standard 90 meaningful. He points out that the standard now demands that engineers, designers, and building managers understand how all systems that control energy in a building interact. "It's not only the boilers and coolers, or even the fans and pumps that matter most," observes Pearson, a designer who became a mechanical engineer and an authority on energy conservation. "It's how all these systems work together that is critical."
The latest ASHRAE standard delineates this system's approach to energy conservation in building design or renovation. However, it does complicate matters. Pearson says designers who follow the standards need a certain amount of technical knowledge about how things work to imbue their designs with energy-efficient features. "You can have what appears to be a good idea but it may not work if you don't understand the interactions."
Audit Skills: Doing the Detective Work
Most audits are done on existing buildings with the emphasis on how systems operate and how they are maintained. For recently constructed buildings, Fetters maintains that a final "commissioning" step should be part of the process. That is where an energy expert performs a post-construction audit to verify that all systems were installed as specified and perform correctly. Last but not least, he notes, is the task of making sure there are operating instructions for all building systems.
People who do the detective work of an energy audit need skills that keep pace with the sophistication of energy systems. Practitioners who specialize in audits, professionals in charge of building or plant operations, and energy managers hired by corporations to oversee performance improvements rely on a basic set of skills.
Observation
Pay attention to details. Look beyond the obvious. These are fundamental to a successful audit. "I used to think knowing a lot about lighting was the key to a good lighting audit," says Fetters, who has written widely on the fundamentals of energy management. "Of course, it is the professional knowledge necessary to recommending lighting solutions that improve productivity and save energy. But it can get in the way of observation and data collection—counting fixtures and taking good notes on the existing lighting system." Detective-like observation is a learned skill that Pearson agrees helps an energy manager or outside professional identify how well a building's energy systems work in tandem.
Analysis
From the simplest survey of energy use to a complex investment-grade audit, skill in analyzing data is necessary. Just analyzing a year's worth of utility bills tells something about energy consumption, says Pearson. Knowing how to "read" what an on-site inspection reveals about building use and system maintenance is equally critical to making valid audit recommendations. Trained analysis also comes to bear when interpreting the performance improvements once a system is upgraded.
Stamina
An on-site survey of energy use in almost any building or commercial space involves checking all functional systems and requires long days of noting detail, gathering data, and making certain all measurements are accurately done. "This is not a practice for the faint of heart," Fetters warns, only partly in jest. Keeping sharp and staying focused over thousands of square feet can be an endurance test.
Tooling an Audit
Any audit that goes beyond the analysis of utility bills requires a variety of tools to measure capacity and record variables. Those Pearson and Fetters find useful include simple and advanced instruments.
Data logger
This pint-size, battery-powered tool is an inexpensive method of collecting usage and operational data for up to 10 days. Loggers can be programmed to record continuous information on temperature, humidity, electric use, and other factors. Measurements often are downloaded into a laptop computer to analyze the data. "Loggers allow you to demonstrate the basic impact of a change more quickly," Pearson says, describing how he used a data logger to show the cooling benefits of a client's altered air exchange system. Loggers also are used for "trend logging" to monitor changes over time.
Lighting loggers
Another analysis tool, this logger measures time of use. Similar to an "occupancy logger," the lighting logger registers when lights are on and for how long. Data gathered this way measures usage for an extensive audit and also serves up reports on post-upgrade savings.
Flicker checker
A simple, hand-held tester much like a spinning-top toy, this device quickly identifies whether a light fixture has a magnetic or electronic ballast.
Light meter
Fetters notes that a good digital version of this tool accurately measures existing light levels in a space or room.
Ultrasonic range finder
One of the newest tools in the energy auditor's toolbox is something widely used in the building industry. It takes the square-foot measurement of a room, providing critical information when calculating lighting, heating, and cooling standards, space-by-space.
Lighting test sheet
Lighting auditors rely on these special test sheets to determine "veiling reflections," a problem that occurs when reflections of incident light are superimposed on diffuse reflections, obscuring details of a task. Identifying and correcting this problem greatly improves the work environment.
Hand-held computer
A walkthrough energy audit, whether targeting a single system or everything, is made easier when observations and data can be entered on-site, accurately, and legibly into a hand-held computer.
As in every field, technology has refined the auditing process. Computerized models, laser measurements, and other innovative tools give today's auditors and designers precise information they can translate into tangible and tenable results.
Audit Futures
Every energy audit that leads to evident improvement reinforces the value of a process that facility engineers, energy managers, and others with a stake in conservation and comfort are using more widely. Doing simple analysis of monthly bills to find preliminary solutions. Investing in comprehensive audits to uncover a complement of fixes that improve efficiency. Applying advances in energy system design during planning and construction to ensure a new building operates efficiently from day one. These scenarios signify that energy audits have an important place in building maintenance and design, as do the skills needed to conduct or contract for such audits.
John Fetters, Dick Pearson, and other engineering and energy experts provide in-depth and hands-on training twice a year in a dynamic professional development program on the "Fundamentals of Energy Auditing," offered by the Department of Engineering Professional Development at the University of Wisconsin-Madison.
Learn more about energy courses sponsored by the Department of Engineering Professional Development by searching for "building energy" or by calling 800-462-0876.
Written by Mary Maher
This article is based upon work supported by the University of Wisconsin–Madison Department of Engineering Professional Development. It is for general information and distribution. It is not intended to provide specific solutions or advice for specific circumstances, which should be sought from appropriate professionals.