apperson energy management

MORE ON THE I.R. CAMERA

In our last discussion, we were talking about the I.R. or Infrared camera. This is also called a “thermal imager”. These names are self-explanatory in that the camera senses and records images in the “infrared” or heat portion of the electromagnetic spectrum. And “thermal imager” relates to the same thing, an image created using heat or “thermal waves”. Last time I said that we had three tools for testing things in a home pertaining to energy efficiency or utility savings and that is really not exactly correct. The blower door and duct pressure tester and now the thermal imaging camera are just the largest and most impressive of our tools, but we actually have many more we use. We have a combustion gas analyzer to check whether the gasses coming out of your water heater or furnace are burning completely. Incomplete combustion can be a major health hazard if the appliance is allowed to back draft and the products of incomplete combustion are allowed to build up inside the home. These gases can be deadly.

We also have a handheld gas sniffer which we use to inspect every inch of incoming fuel gas line to make sure there are no leaks of fuel gas. Most of these gasses are heavier than air and when they leak they settle in pockets at the lower level of our homes and just wait for a source of ignition. 

We have an aerometer with which we can measure how much air comes out of a heat register and a number of other small very useful tools that give us a large amount of information about your house and the safety of its gas burning appliances.
                                   
                                                    BACK TO THE I.R.

However, the newest, coolest tool is the I.R. camera, which we had been discussing last time. And as we were saying, what better tool to measure heat leaving a structure than a tool that sees and records what it sees in heat waves. These cameras were so expensive just a few years ago that not many people in the business owned one. It doesn’t take long in our world for anything involving electronics to become more user friendly and cheaper and that has held true with the I.R. camera. While a basic beginner’s model used to be around $20,000, we now have entry-level models in the $2,500 range with ones having acceptable sensitivity and range with recording ability being around $5-$8000. While not cheap, it’s now in the realm of lease and financing, thank goodness!

So we have a tool that senses temperature differences in materials. The camera has a screen to which the user sees an image of the target area and when set to its thermal image mode the image is presented as a picture that changes color as the temperature of the materials registers warmer or colder than the surrounding materials. The standard setting gives you a range of about 30 degrees, and you have a color palette that goes from dark blue to bright red as those 30 degrees are transversed. So you see an image of your target area but in false color, with the cooler areas being dark blue and the warmest showing as bright red. The newer units have a “picture-in- picture” setting which allows the operator to take a picture with half of the frame being a normal photo and the center of the shot being in the I.R. mode. This makes it easier to locate the areas for investigation if you can see part of the area as a real light image photo.

                                                       AT THE BUILDING

Typically the operator will set an appointment with a building owner and have them get the structure heated up in advance. It typically takes at least an 18-degree temperature difference between inside and outside to get the difference to register properly. The measurements are usually taken from inside the building due to the effect of wind and direct sunlight on the surface to be viewed. Just a small amount of wind can compromise accuracy. A 10 mph wind can distort results by over 50%. The sunlight warming your wall surface has a similar effect. So viewing is done from the interior. The surface of a wall or ceiling can have drastically different reflective qualities and it takes a skilled operator to make sure he is looking at things correctly. An unpainted surface will give a much different reading than a painted one with the painted one being the most accurate. Glass surfaces do not react at all and special attention must be paid to reflections and “bounce-back” images of the surfaces that reflect an unwanted image back onto the surface you are trying to measure, even something as unforeseen as the operators forehead reflects an image back to your target.

The better units can record hundreds of images on a removable disk or have internal storage, and can also record your voice explanations of each shot.

For the building science industry the advancement and affordability of these tools has opened a whole new world in home performance. To be able to actually “see” the heat leaving a building takes a lot of the guesswork out of what we do.

These cameras, of course, have many other uses, anything that gets hot when it malfunctions can now be observed without touching it. Overloaded fuses, overheating electrical and combustion motors, bearings that are wearing will get hot. Rumor has it that during the last outbreak of whatever exotic flu bug we were concerned was set to invade our Country, that thermal imagers were set up at airport arrival gates and everyone who got off a foreign plane had their temperature taken by a thermal imaging device.

So big brother is not only watching you but can now also take your temperature. Wow.

 For questions, corrections, concerns or requests please email Jim at jim@appersonenergymanagement.com  

or go to the website.  Jim has owned Apperson Insulation for 25 years, installed energy conservation items on over 3000 local homes. Has been a certified HERS rater since 1993 w/ over 1500 audits. He has State licenses in General Building, Insulation & Windows. Is a member of Build It Green, CBPCA & is BPI certified

THE I.R. CAMERA AND OTHER TOOLS OF THE TRADE

Back in the early 1980’s when our company was first getting into the energy conservation business, the whole concept of what energy efficiency in a home means and how to achieve it was in its infancy. The birth of the field was basically a reaction to the oil embargo of the late 1970’s. Up until that happened no one thought much about conservation or the fact that we wouldn’t always just have as much oil, and therefore cheap electrical power, as we would ever want or need. The embargo opened everyone’s eyes to the fact that oil is a finite resource and we, in the United States, do not own or produce as much as we use. The first attempts at residential conservation were put forth by the utility companies (PG&E in our area) who were realizing the shortfall of fossil fuels to generate power at the same time construction of nuclear power plants were meeting with strong opposition from the public.

                                  THE ZERO INTEREST LOAN PROGRAM

Since the utility sponsored programs were the only game in town we took their methods as gospel. We had no real testing tools at the time so the concept was a “one-size-fits-all” kind of approach. You went to someone’s home and you looked at a group of six things that the utility company told you were what made a house waste energy. The attic insulation had to be a certain level, the doors had to be weather stripped, the showers had to have low flow heads, the gaps in the outside trim had to be caulked and the water heater had to have a blanket. If any of these were missing you went “Ah-ha” (and in most cases all were missing), and you convinced the homeowner if took advantage of an interest free loan from PG&E he could then install these items and his heating and cooling bills would drop sharply. In our local program if you did install these items you could then go on and get another loan for more extensive things like wall and floor insulation and even dual pane windows. 

This was all fine while it lasted, which was 3-4 years and then the ZIP program ended. It did a lot of good for a lot of homes but without any means of testing or verification of results the real benefits were always in question.

                                                    TESTING & TOOLS

As it became more evident that energy conservation and reducing the use of fossil fuels is a serious matter, even to the point of national security, a better way was needed to make the process custom to each building since each building is so different. First we saw energy audits being done on structures in such a way as to be custom to a particular building. But the real changes started 10-15 years ago when we saw actual testing equipment designed strictly for conservation. We were introduced to the” blower door” about that time and the “duct blaster” shortly thereafter. These are both pieces of testing equipment designed strictly for building energy conservation, and both work on the same principal. The blower door pressurizes a whole house (or commercial building) after sealing up all the openings, so we can tell how leaky that building is. The duct blaster does the same for the HVAC duct system. Air leakage and infiltration are major factors in the loss of conditioned air and there was finally a tool to quantify and locate this instead of just throwing caulking at the same places on every building and hoping those were the correct spots.  
                                           AND NOW THE I.R. CAMERA

About the same time another tool was becoming available for building shell diagnostics. The Thermal Imager or Infrared Camera. These are fantastically useful instruments.

Visible light consists of electromagnetic waves of a certain wavelength. When those same waves are shorter and their crests closer together than visible light, they fall into the “ultra-violet” part of the spectrum, and as they get shorter yet they become X-rays and finally Gamma rays. If we head back up the other way on the spectrum just past visible light, as the waves become longer we have the infra-red part of the spectrum, then longer still they becomes Micro-waves and then radio waves. But it’s the infra-red part that these thermal imagers sense and record. The infra-red is heat. And if we are studying heat loss what better tool than one that can actually see and record heat leaving a building? Together with the blower door and duct pressure tester we have a way to test an individual structure and measure its performance and record the results of the testing. We then can compare our efforts after our energy efficiency measures are installed. We now have a way to see if what we did actually worked. The draw back to this particular tool was and is its cost. The first I.R. cameras had to be artificially cooled with liquefied gas and were large and cumbersome making them not feasible for building shell diagnostics. It would have been easier to bring the building to the camera at the time. We’ll pick it up here next time.