A commercial energy audit – think of it as a medical check-up for your building – is the best way to determine exactly what energy improvements your building needs and how quickly your investment in those improvements will be paid back through energy savings. And just like a medical check-up, you want to have your commercial energy audit performed by a trained, qualified professional. When you hire someone to perform your audit, check to see if they’ve been certified by accrediting organizations like the Association of Energy Engineers (AEE), the American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE), or the Building Performance Institute (BPI). There are instructions available online for conducting a do-it-yourself commercial energy audit, but going back to our medical analogy, would you want to perform a do-it-yourself appendectomy? This is something that’s best left to the pros. A certified efficiency expert will not only have the knowledge gained through extensive training but will also have the tools and equipment needed to conduct thorough and precise testing of all your energy equipment as well as the building envelope.
There are essentially three levels of commercial energy audits that can be performed on your business, as categorized by ASHRAE. A Level I audit, sometimes referred to as an energy survey, consists of a review of the facility’s utility bills and a basic visual inspection of energy-consuming equipment on a walk-through of the building. It’s intended to provide a quick overview of the energy-saving opportunities for the building using no-cost or low-cost measures. The no-cost measures often include educating the building’s maintenance staff and occupants on energy conservation, making sure they turn off lights and electronic equipment that aren’t in use. Low-cost measures can include upgrades to lighting or thermostat controls. The Level I audit report may also suggest that a more comprehensive evaluation is needed to look at the cost-effectiveness of more expensive energy efficiency measures.
A Level II commercial energy audit is a much more detailed building survey and energy analysis. It generally starts with the efficiency expert interviewing the building’s key players – everyone from the owner or manager down to equipment operators, maintenance staff and occupants – to get a complete understanding of the building’s operations, listen to concerns or problems and clarify the goals of the audit. The efficiency expert will then study the building’s consumption of both electricity and natural gas by end-use to see where opportunities for savings exist. Additionally, the efficiency expert will look at the utility rate schedules under which the building is buying its natural gas and electricity to see if money could be saved by switching to another rate schedule. If the local utility offers a demand response program (a financial incentive to customers who voluntarily cut back on their usage during periods of peak demand), the efficiency expert will determine if participation in that program is feasible.
The efficiency expert will examine all the equipment in the building that uses energy, noting the age, size, condition, type of technology and operating characteristics of each item. This includes lighting, heating, hot water, air conditioning, and air circulation as well as any equipment that may be unique to your type of business (i.e., refrigerator and freezer cases in supermarkets; ovens and dishwashers in restaurants). Even computers, printers, copy machines and other “plug loads” will be looked at. Measurements will be taken on the levels of lighting in terms of its brightness and focus. In situations where buildings have exterior as well as interior lighting – like for signage, security or parking lot illumination – those fixtures will be examined as well. Within the realm of HVAC, the efficiency expert will measure temperature, humidity, airflow and air quality levels throughout the facility. These are things that not only affect the performance of energy equipment but also impact the health, safety and comfort of the building’s occupants.
In addition to carefully studying the condition of your energy-consuming equipment, a Level II commercial energy audit will also examine the condition of the building itself. The efficiency expert may use infrared thermography to detect heat that’s escaping from the building envelope. By taking thermal images with infrared video or still cameras, the efficiency expert can detect temperature variations on the building’s outer surface and determine if insulation is needed. The efficiency expert will also evaluate the airtightness of a building by performing a blower door test. A large fan is mounted in an exterior doorway and blows the air inside the building outdoors, lowering the air pressure inside. If the building has any leaks in its envelope, they’ll be detected as outdoor air is drawn into the building because of the disparity in air pressure.
Following completion of the audit, the efficiency expert will prepare and deliver a report (possibly including an in-person briefing with the building’s management and staff) recommending energy efficiency measures, changes to system controls, operational changes and potential capital upgrades. The report should include the cost of implementing the recommendations and an estimated payback period for each. It’s also possible that the report may suggest that building management should dig deeper into energy solutions by undertaking a Level III audit.
A Level III audit is sometimes called “investment grade” because it offers the building owner a more complete understanding of the costs, benefits and performance results outlined in the Level II. A Level III audit usually employs a computer model to simulate how a brick-and-mortar building reacts to changes in its energy systems or modifications to its structure. It involves much more detailed data collection over a period of weeks or even months, tracking the operation of pumps and motors, temperature, humidity and lighting levels and other factors. Once the computer model responds like the real building, changes to energy systems can be simulated with very accurate results.
One of the key elements of any commercial energy audit is benchmarking. Essentially, benchmarking compares the energy use of your building with other buildings having similar characteristics. This allows you to see how well your building stacks up against its peers. The federal government’s Energy Star program has a benchmarking tool called Portfolio Manager which rates your building on a scale of 1 to 100. If your building scores a rating of 50, for example, it’s typical of similar buildings in terms of energy efficiency. A rating of 75 means your building is an energy superstar, while scoring a 30 on that scale is an indication that your building needs some serious efficiency improvements. Buildings should be benchmarked on a regular basis to see how well they’re keeping up with the Joneses. An EPA study showed that buildings that benchmarked regularly over a three-year period averaged annual energy savings of 2.4%, with total savings of 7% over that time and an average increase of six points on their benchmarking score.
A commercial energy audit is a necessary first step on the journey to creating an energy-efficient build – just like a visit to the doctor’s office is a necessary first step on the journey to good health.