Every Picture Tells a Story
If you’re in Florida and you step outside on an August afternoon, chances are good that it’s going be hot and muggy. Conversely, if it’s Alaska in January, it’s fairly safe to say that it’s going to be cold and windy.
You can try to guess what the temperature, humidity level and wind speed might be, and you might come reasonably close, but wouldn’t it be easier with some tools? Perhaps a thermometer or a wind gauge? Such instruments can provide precise readings, either confirming or denying your speculations.
Now, imagine the setting is an industrial facility or factory. A plant engineer knows how much energy the facility is using and what its energy costs are. He knows the numbers could be better than what they are. He might be aware that if insulation were installed on some those bare pipes, valves and other components, the plant’s performance could improve significantly.
But the tricky part is identifying where the primary trouble spots are, and how to fix them. A plant engineer has a million things to worry about, and insulation is likely not the number one priority. Ideally, that’s when he’ll contact someone with the expertise, skills and tools to provide solutions. Perhaps that person is an energy auditor certified through the National Insulation Association’s Insulation Energy Appraisal Program (IEAP). And it also may be someone who’s also a certified thermographer. Utilizing a specially designed camera, a thermographer uses infrared imaging and measurement to "see" and "measure" thermal energy emitted from an object.
Thermal, or infrared energy, is light that’s not visible because its wavelength is too long to be detected by the human eye. It’s the part of the electromagnetic spectrum perceived as heat. Unlike visible light, in the infrared world, everything with a temperature above absolute zero emits heat. Even very cold objects, such as ice cubes, emit infrared. The higher the object’s temperature, the greater the infrared radiation emitted. Infrared allows us to see what our eyes can’t.
Infrared thermography cameras produce images of invisible infrared or "heat" radiation and provide precise non-contact temperature measurement capabilities. Nearly everything gets hot before it fails, making infrared cameras valuable diagnostic tools in many diverse applications. And as industry strives to improve manufacturing efficiencies, manage energy, improve product quality, and enhance worker safety, new applications for infrared cameras continually emerge.
If you talk to thermographers, the technology has opened many eyes. Kevin Hedgers, industrial division manager for NYCO, Inver Grove Heights, Minn., says thermography adds professionalism and a level of sophistication to the process.
"The bottom line is that it absolutely provides credibility to the whole audit process by providing visual documentary of your work," says Hedgers, a certified IEAP appraiser. "You need to have that credibility."
Steve Campbell, Owens Corning national specifications manager, insulating systems business, southern region, says thermography has been a terrific tool for energy audits.
"You’ve heard the saying about a picture being worth 1,000 words," says Campbell, another IEAP alum. "In this case, a picture can be worth hundreds of thousands of dollars. [Thermography] has been a real good selling point. It gives maintenance people documentation to take to management to show how it can help."
Sir William Herschel, an astronomer, discovered infrared in 1800. He built his own telescopes and was familiar with lenses and mirrors. Knowing that sunlight was made up of all the colors of the spectrum, and that it was also a source of heat, Herschel wanted to find out which color(s) were responsible for heating objects. He devised an experiment using a prism, paperboard, and thermometers with blackened bulbs where he measured the temperatures of the different colors.
Herschel observed an increase in temperature as he moved the thermometer from violet to red in the rainbow created by sunlight passing through the prism. He found that the hottest temperature was actually beyond red light. The radiation causing this heating wasn’t visible. Herschel termed this invisible radiation "calorific rays." Today, it’s known as infrared.
Infrared Cameras-How Do They Work?
An infrared camera is a non-contact device that detects infrared energy (heat) and converts it into an electronic signal, which is then processed to produce a thermal image on a video monitor and perform temperature calculations.
Heat sensed by an infrared camera can be precisely quantified, or measured, allowing a user to not only monitor thermal performance, but also identify and evaluate the relative severity of heat-related problems. Recent innovations, particularly detector technology, the incorporation of built-in visual imaging, automatic functionality, and infrared software development, deliver more cost-effective thermal analysis solutions than ever before. Infrared thermography allows a user to instantly visualize and verify thermal performance. In June 2001, Maintenance Technology magazine reported a $4 return on investment in for every $1 spent on infrared inspection.
Campbell, based in Big Sandy, Tenn., is a certified level II thermographer. A level I certification is essentially described as qualitative, meaning "you can basically compare picture A to picture B," says Campbell. Level II is more quantitative, allowing for more analysis between numbers and temperatures with the infrared images. A number of infrared technology manufacturers teach classes on thermography. Campbell attended a four-day classroom session taught by a manufacturer. The class includes a 75-question test that must be passed to advance to each level.
However, he points out, "The best learning tool for infrared is experience. The classroom is important, but the field work is equally important."
Campbell has been using thermography for more than three years, since Owens Corning began its Thermal Analysis Program. The Owens Corning program combines inspection, analysis and reporting services in a process designed to identify opportunities to optimize thermal insulation systems. A customized report is generated after visual inspections, infrared imaging and analysis of existing mechanical insulation.
Campbell says that a high quality thermography package-camera, software, accessories and training-can cost between $70,000 and $80,000. He says that the camera works just like a video-basically like a hand-held camcorder.
In a typical site visit, Campbell says he will do a pre-audit interview with the person in charge of facility maintenance. He might be asked to measure temperatures above a certain level. Once the parameters are set, Campbell says, "We scan until we see a problem. Then we record it, freeze the image, save it to a PC and create a digital image. We also take detailed notes and have somebody from the company with us to verify where the photos were taken, since most piping and components look the same everywhere. We get about 50 pictures on a good day."
Armed with the infrared documentation, and assisted by computer programs such as 3E Plus®, Campbell can provide a detailed report to the facility engineer and make specific recommendations explaining where improvements can be made through insulation. He says the visual images speak for themselves.
"You have to show it to sell it," Campbell says.
Hedgers agrees that the infrared images, combined with the written reports, make the process much easier for him and the client. As with Campbell, Hedgers uses 3E Plus® as a supplement to the infrared analysis. He can translate the digital images into tables that show how much it would cost to insulate a specific valve, pipe or other types of equipment, and how long the payback period will be.
"It allows them to prioritize," Hedgers says. "In one area, it might be a 3-month payback, and in another a 3-year payback. They can choose whether they want to invest some now and some later."
Personnel protection is another area where thermography can help. "It’s a not just a good energy tool, but it’s also a good safety tool," Campbell says. "If somebody gets burned, you’ve got a big problem on your hands."
In 1999, Unilever-Best Foods Inc. implemented a corporation-wide program to improve energy efficiency and reduce emissions. In 2001, as part of that program, Hedgers conducted an insulation audit at the Unilever Rexdale plant located near Toronto, Ontario, Canada (see November 2001 Insulation Outlook). Hedgers’ work has helped Unilever save some $340,000 in energy costs (over two years). Using infrared images and 3E® Plus, Hedgers provided recommendations that allowed the facility identify areas to add extra insulation.
Prior to the audit, the plant’s tanks were insulated, but manholes and agitators weren’t. Following the audit, 101 manholes, 74 agitators and 28 tank patches were insulated. The implementation cost was $29,517 ($18,615 U.S.) and the total annual savings was $51,606 ($32,545 U.S.)
Doug Dittburner, chief engineer and energy team leader for the Unilever plant, says that Hedgers’ thermographic images and accompanying information made a big difference.
"Our philosophy is ‘data rules’," Dittburner says. "The infrared gives you information that you wouldn’t otherwise have. Someone can say, ‘This is what you need to do,’ but the infrared really shows you the whole picture. The calculations say that this is what you have and this is what you need to do. It’s well worth the investment."
Since beginning its energy program, Unilever, in part due to Hedgers’ efforts, has enjoyed an overall energy savings reduction of $2.3 million ($1.45 million U.S.), with an investment of $1.1 million ($693,727 U.S.). Dittburner adds that the plant has reduced its natural gas usage by 6.3 million cubic feet, its electricity usage by 4.6 million kilowatt hours, and water by 78 million gallons. It has also cut its greenhouse gas emissions by 11.9 million kilograms of CO2.
Looking for Payback
Campbell has also conducted a number of insulation audits as part of Owens Corning’s Thermal Analysis Program. One successful project he was involved with was at the Cargill Foods facility near Memphis, Tenn. Cargill’s operating engineers are interested in any project that will pay for itself within three years. When they saw payback projections in a insulation audit, the engineers immediately had the recommended insulation installed.
The engineers knew they had a lot of pipe that needed to be insulated, but that wasn’t the issue. The questions for them were about the payback period and where to start.
"The project was something we wanted to do for quite a while but we needed to determine the payback for the investment," explained Drew Heise, project engineer at the Cargill facility that makes corn sweeteners, refined corn oil and animal feeds. The operation employs more than 300 people and is spread over about 3.5 million square feet of President’s Island, located along the Mississippi River.
Heise says the audit "identified each specific piece of equipment that needed to be insulated. It tells what the equipment is, the average temperature around the equipment, wind speed at the time of the analysis, the length of pipe to be insulated and the surface temperature of pipe. The report also lists the carbon dioxide emissions related to the energy loss. Then the report gives everything a priority rating-it’s a one, two or three-and they list an estimated payback time for each piece of equipment.
He adds, "Most of them (payback times) were great. There were many well under a year-like 10 months and eight months. Both of those were highly rated as a ‘one.’ We did all of them, even the three’s. Dollar savings was the reason behind doing the project because everything is driven with a payback. Typically here, we’ll do anything that can be paid back within three years."
Heise says that adding insulation was something that needed to be done. "A lot of this is real obvious. If you see 20 feet of exposed steel pipe going right into a boiler, it doesn’t take a genius to realize that it needs to be insulated. We decided to make a record of the situation by first having an [insulation audit] done on all of the hot spots. That gave us something to work with; it offered direction."
Cargill engineers say they are also concerned about safety and environmental issues.
"The report indicates what the future surface temperature might be," explained Heise. "In one example, the report shows a recorded surface temperature of 763 degrees (fahrenheit). After insulating with 3-1/2-inch-thick, high-temperature pipe insulation, the surface temperature will be 136 degrees (F). Typically, 120 or thereabout is considered safe and doesn’t need to be insulated. The projected temperature of 136 degrees (F) is not too far above that. Obviously, 763-degree (F) surface temperatures are a safety issue. Even if the payback period doesn’t fall within our threshold, we would do that one as an environmental health or safety issue."
Heise was also pleased that the report lists the carbon dioxide reduction in pounds per year for each insulation project. If the equipment is insulated as recommended, the report indicates how much the improved efficiency will reduce the carbon dioxide created in burning fossil fuel to generate heat that was previously lost.
"There are limits to what a facility can actually put out into the air," Heise says. "We are only permitted to emit so much to the atmosphere and we can’t go above that limit. Reducing emissions from one piece of equipment-because you are running more efficiently-can open up opportunities in other areas of the plant, if you need to add a burner somewhere, or expand a boiler, for example.
Versatility and Value
Hedgers says thermography is versatile. Earlier this year, he conducted an infrared audit at a 150 megawatt power plant in North Dakota. He was able to document heat losses and the amount of emissions being released into the atmosphere. As was pointed out by Heise at the Cargill plant, industrial plants can only emit emissions to a certain threshold. Hedgers’ work assisted the facility in reducing emissions and avoiding possible fees for exceeding the limit. Also, at a prominent Midwestern health care facility, Hedgers helped save $30,000 in power generation costs over about an 18-month period.
Overall, Hedgers says, thermography adds the kind of precision to the energy audit process that clients appreciate.
"They seem very impressed with the documentation-having a more detailed breakdown estimate of repair costs, and how much energy they’re using. It’s a nice value added service."
When he began using infrared technology, Campbell admits that he didn’t know what to expect. But it didn’t take him long to realize what a tremendous asset it is.
"I’ve been in the business for 27 years, and it’s the best tool to do an energy audit that I’ve run across."
Editor’s Note: This story contains partial excerpts from an Owens Corning Thermal Analysis case study prepared by Bill Hamilton. For a comprehensive look at Kevin Hedgers’ energy audit at the Unilever Toronto plant, see his November 2001 Insulation Outlook story, "Insulation Energy Appraisal."