Energy Audit Tools
There are many tools that can be used to perform a wide variety of audit tasks. To perform a simple walk-thru audit, the auditor may only need a hard hat, safety glasses, a flash light, and note pad. The complexity (and cost) of the audit will determine the tools that are required. Some auditors specialize in only certain functions and will therefore have premium tools for that function; other auditors may sub-contract for those services – such as blower doors, thermal scans and comprehensive compressed air analyses.
It will be difficult to justify a premium for-fee audit without including the use of tools that will be used to gather data that is not otherwise available to the customer. On the other hand, free walk-thru audits are generally performed with no tools and a ‘no touch’ policy.
The following tools offer a cross-sampling of typical tools that an auditor may use.
Ultrasonic Compressed Air Leak Detectors
Ultrasonic leak detection is extremely broad based. Sensing ultrasounds generated by a leak can be used to locate leaks in pressurized systems regardless of the type of gas used. This is especially beneficial in areas where there is a saturation of gases or where a wide variety of gases, pressurized vessels and vacuum processes exist. Time and convenience are also improved with ultrasonic detection since equipment may be tested while on-line.
How Ultrasonic Leak Detection Works
During a leak, a fluid (liquid or gas) moves from a high pressure to a low pressure. As it passes through the leak site, a turbulent flow is generated. This turbulence has strong ultrasonic components which are heard through headphones and seen as intensity increments on the meter. It can be generally noted that the larger the leak, the greater the ultrasound level.
Leak Detection Method
Ultrasound is a high frequency, short wave signal. The intensity of the ultrasound produced by a leak drops off rapidly as the sound moves away from its source. For this reason, the leak sound will be loudest at the leak site. Ultrasound is considered fairly “directional” and therefore, locating the source (i.e. the location) of the leak is quite simple.
For detection, scan the general area of a suspected leak and listen for a hissing sound (similar to the sound you hear when you fill a tire with air). Move in the direction of the loudest sound. If it is hard to determine the direction of the noise, reduce the sensitivity until direction can be established. Follow the sound and continue to reduce the sensitivity to determine the direction of the leak. In order to confirm the leak site, move the scanner back and forth over the suspect area. The sound level should increase as you pass over the leak. In some loud factory environments, frequency tuning may be required.
For more information see www.uesystems.com
Flue Gas Analyzers
Flue Gas Analysis is performed by inserting a probe into the flue of the furnace, boiler, etc., between the last heat exchanger and draft diverter or any source of make-up air that could enter the flue that did not pass through the combustion process. This is known as ‘in situ’ testing. It is also necessary to take a combustion air temperature measurement, or ambient temperature if that is the source of combustion air.
Depending on the gas being measured, most probes today are either infra-red or some sort of electrochemical. Not all gases are directly measured; some values are calculated based on gases that are measured and then factored based on input fuel properties.
Hand-Held IR Themography Cameras
IR Cameras can be used to not only detect hot/cold spots, but can also detect moisture trapped in building walls and ceilings and also identify equipment and mechanical problems before the actual failure occurs. The latest generation of cameras are smaller, more accurate, more rugged, interface with computers for picture processing, and even cost less. However, they are still not ‘cheap’ enough for every tool box to contain one.
More info on IR Thermography
Remote IR Thermometers
The ability to quickly and with reasonable accuracy take a temperature reading on any surface is a huge advantage for auditors. IR Thermometers can be used to check air temperature when reading is taken off a surface directly in the air flow path, such as the face of a register. Steam traps can be checked for proper function (if not covered in insulation). Building components can be checked for hot/cold spots. A wide range of instruments are available in a range of prices from under $100 to about $500 for temperature ranges required by auditors.
For more information, conduct a basic web search or check with any industrial supplier.
Clamp-on AMP Meters offer a way to quickly and easily read the amount of power being drawn by an electrical appliance or piece of equipment. The place where readings must be taken is where the meter can be clamped around the power lead to the equipment. For 3 Phase equipment, individual readings must be taken on each Phase. This is not always possible. Another thing to consider is that taking this kind of reading requires a safety risk that some facilities will not allow. If a power panel or motor starter panel must be opened in a union shop, it will likely have to be performed by an on-site union electrician only. This is an advantage (having help) assuming such a helper is available and is knowledgeable of the equipment.
When taking AMP readings, consider the load factor of the equipment. The instantaneous reading taken by a hand-held meter may or may not reflect the total or average use of the equipment during its entire running cycle.
Recording AMP Meters and Data Loggers are used to record usage over a period of time. They are installed and left in place for a period of hours or days. They are then retrieved and connected to a computer to download their readings. Reading frequency may be from fractions of seconds to several minutes. The number of readings stored will depend on the amount of memory the recorder contains.
Watts-UP is a residential recording meter that reads-out directly in watts/kWhs. They are designed for residential equipment such as refrigerators, or anything with a single-phase plug.
Electric Motor Efficiency Measurement
Reliance Electric Motor Efficiency Wizard
From the number one name in engineered motor solutions comes an unsurpassed tool for accurate electric motor efficiency measurement. There is no other device or product available for easy, accurate efficiency measurement on in-service motors. The Motor Efficiency Wizard can measure the efficiency of any squirrel cage induction motor up to 1000 amps.
Unlike previous methods,the Motor Efficiency Wizard does not require removing the motor, uncoupling the motor from its load, or transferring the unit to an off-site facility to perform efficiency testing. All electrical measurements can be made at the motor disconnect point, without the need to open the motor conduit box. Lab tested accuracy to within 1%.
The Reliance Motor Efficiency Wizard combines a proprietary software package with a portable power monitor that determines the motor efficiency using simple measurements. By measuring the input power, voltage, current, speed, temperature, frequency, and resistance at two motor load points, the Motor Efficiency Wizard provides accurate efficiency data on easy to read output screens.
By using the determined efficiency value, the Motor Efficiency Wizard calculates and displays the potential savings in energy cost as a result of replacing the inefficient motor with a Reliance premium efficient design.
For more information see www.reliance.com
Sources: Compiled by Bob Fegan based on sources referenced and linked above 9/2004; rev 1/2009;