by Michael Stuart
Lately, everyone is talking about energy efficiency, including better building performance, being "green" and saving money. It's everywhere you look: on television, in print magazines and newspapers, and on the Internet. The only way you could miss it would be if you have been living in a thatch hut on a remote desert island. (That may not necessarily be a bad thing; at least you probably have a low carbon footprint and a little peace in this hectic world!) Whether you are specifically concerned about any of these things is probably determined in part by your financial situation, your overall concern for your future and that of coming generations, or by peer pressure. Regardless, sooner or later, we must all pay attention to what's happening around us. Eventually, we must all do our part to make a better world to live in, even if it's only in small ways. (And I've never heard anyone complain about reducing their utility bills every month.)
With all of the overwhelming hype and media attention given to becoming more energy efficient and reducing energy costs, it's often difficult to determine what "small ways" are right for you. One thing that you can do is have an infrared inspection performed on your home, apartment, or condominium, and take some actions based upon the findings. Infrared inspections are becoming a standard practice of those professionals who perform complete energy audits of residences and commercial buildings alike. They are non-destructive, safe, and often quite reasonably priced. What these inspections can discover and the subsequent paybacks can be nothing short of remarkable.
Infrared thermography is nothing new. It has been regularly used for military applications, inspection of industrial equipment and electrical systems, and commercial building diagnostics for well over 30 years. In recent years, however, due to technology improvements and overall cost reduction, infrared inspections have become much more commonplace (and expected) in residential energy and weatherization audits. Many thermal imagers are easy to use, rugged, reliable, and able to see and communicate things that our eyes alone cannot.
What exactly can a thermal imager see? Good question. These amazing devices allow the user to see infrared energy on the surfaces of different materials. This infrared energy - or heat - can be coming from different places and by varying means. The important thing to remember is that infrared energy is everywhere, in everything, and always moves from areas of higher concentration to areas of lower concentration, that is, "hotter to colder."
So what does this mean to the energy auditor or home owner? If you have a thermal imager, thermography training, and a proper understanding of building materials and techniques - and you know where the heat is coming from and how it's getting there - you can see things that others cannot. You can see in a whole new light, infrared. With the proper use of a thermal imager, you can see where there may be missing or deteriorating insulation, improper construction techniques or repairs, and air leaking into or out of crevices, holes, gaps, and other penetrations in the walls, ceiling, or floor of a house. You can also see if the windows and doors are as air-tight as you think. Ever wondered where that draft was coming from? Well, here is a way to pinpoint and document it so you can stop it - and stop your money from flying out the windows, so to speak. (Remember those lower utility bills I mentioned?)
Whole house with exfiltration and settled insulation
Air infiltration around window
Air infiltration around door
What's more, a thermal imager can also give the user the ability to detect the presence of moisture (from leaks, floods, or condensation) in walls, floors, ceilings, and certain types of roof. (The R-value rating of building materials and insulation can greatly decrease when wet, not to mention the obvious health problems if mold or mildew begin to grow.) Of course, as also mentioned earlier, electrical problems, such as loose connections and overloaded circuits, which generate even small amounts of unexpected heat, are also something that can be seen in infrared.
While an infrared inspection with a high-quality thermal imager is only part of a complete energy audit, merely finding and documenting the areas of unwanted air infiltration (air coming in), exfiltration (air going out), and inadequate insulation goes a long way towards determining how to better weatherize your home. According to the U.S. Department of Energy, 43% of the energy used by the average home goes to space heating and space cooling. That is a big chunk of change to be inadvertently letting go out the cracks. A home that is weatherized and ventilated properly can be more comfortable, more energy efficient, and have a better resale value than one that's not. The DOE goes on to say that you can reduce a home's heating and cooling costs by as much as 30% through proper insulation and air sealing techniques.
It may seem obvious, but fireplaces are another significant source of escaping conditioned air. Making sure that your fireplace flue closes properly and tightly when not in use is a straightforward concept. However, unwanted air movement also sometimes occurs around gaps between the fireplace brick or stone and the adjacent wall construction. You may not always feel it, but a thermal imager can often see it as plain as day. Some homeowners also have protective glass screens that can be placed in front of the fireplace opening when it's not in use. This too, can reduce unwanted drafts up and down the chimney. In addition, it is also important to perform an infrared inspection of the areas where a chimney sometimes penetrates the attic and/or roof, where unexpected air infiltration and exfiltration can also occur.
House with chimney heat
The DOE also says that 12% of the total energy bill usually goes to heating water for household use. Buying and installing an energy-efficient water heater is a must to keep these costs down. So is keeping the hot water temperature at a reasonable level. Using a thermal imager to inspect the water heater and all hot and cold water pipes is also a good idea. Perhaps you will find a way to better insulate that heater and the pipes so energy is not wasted on standby losses when not in use. Ka-ching! I can already hear the savings adding up. Can you?
Another prime way to find opportunities for energy savings is to have your home's furnace and ductwork inspected. Improperly sealed ducts can inadvertently heat or cool the space in wall cavities, the attic, the basement, or the crawlspace beneath many homes - all areas where we don't actually live. (Well…at least most of us! My apologies to any vampires, gremlins, monsters, bats, or rats in the audience.)
Uninsulated duct work in basement
Here's another thing that thermal imaging can help you verify: A common misconception is that concrete and cement are good thermal insulators. They most definitely are NOT! We think of the foundations and block walls of our homes as solid and secure, blocking out the harshest of Earth's elements. That's an unfortunate perception, since they don't always block out the heat, or keep the heat inside. In fact, concrete and cement, on their own, are actually rather good conductors of heat. This means that if you have not properly insulated your partially exposed basement or block walls, heat could be escaping from your home in the winter and you may never know it. And in summer, the heat coming in through these common construction materials makes it more difficult for you to keep your cooling costs down. Don't worry, though. There are ways to minimize energy loss through these materials. A good energy auditor and weatherization expert can tell you how.
Thermal imaging and infrared inspections can be used equally well on both new and older construction. For new construction, it can help the general contractor and architect to design tighter, better-ventilated building envelopes, and check to see if the HVAC system is properly installed and functioning prior to the completion of the building. This saves rework and provides a better final product for the prospective homebuyer (the seller will usually realize a higher price, as well). For existing homes, thermal imaging offers the homeowner a chance to reduce utility bills, increase overall occupant comfort, and increase resale value for the home when the time comes to sell.
Fixing many problems discovered as a result of an infrared inspection can often be quite easy and affordable, while others are more intrusive and expensive. A certified energy audit professional will be able to give you the details according to each situation and residence, or put you in contact with someone certified to perform weatherization repairs and energy retrofits. Sometimes, all that is needed is a new door threshold, new, properly installed, energy-efficient windows, or a little caulking and sealing around problem areas. Other times, installing extra insulation in the attic or crawlspaces will make a world of difference. Complete reconstruction of your home is usually not necessary to see significant cost savings from weatherization and energy efficiency efforts.
Although I have only discussed a small part of what a complete energy audit comprises, you may now have a better understanding of the important part that thermal imagers play. With affordability, ease of use, and performance increasing, every professional energy auditor and home or building inspector should have this tool in his or her arsenal. The benefits brought to the user in terms of faster, more efficient inspections, better communication and documentation, and opportunity for increased business profitability are amazing; and for the home or building owner, the potential to discover opportunities for lower energy bills, increased occupant comfort and a greener tomorrow are now well within reach!