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Infrared thermography (IR) has been around for many years, but not until recently has it The Building Performance Group uses Flir infrared cameras, the self-proclaimed "Global We use IR primarily to find problems in conditioned buildings that result from heat loss or gain, air infiltration or exfiltration, moisture intrusion through walls and ceilings, and "hot spots" in circuits and electrical distribution systems. IR is particularly valuable in quickly and cost-effectively locating roof leaks in built-up-roof systems (BURs), or flat roofs in general. See the Flat-roof leaks section below for more on flat roof leak detection.
IR is an extremely cost-effective and non-destructive way of discovering areas in buildings that lack insulation, or a sufficient amount of insulation. IR scanning of a building's envelope avoids the expensive and time-consuming costs of removing wall and ceiling board to locate problem areas quickly, and very effectively.
The blower-door uses a pressure gauge, usually digital, which displays pressure and air leakage figures in terms of Pascals (Pa) of pressure and cubic feet of air per minute (CFM), which can then be interpreted by the inspector as to the relatively leakiness of the building.
A typically built new home may have an ACH of around 1.75 ACH. Older poorly weatherstripped and air-sealed homes may have higher than 2.5 ACH. When a blower-door is used in conjunction with an infrared camera, much greater detail on air-infiltration and insulation performance, or the lack thereof, can be seen. See our Resources page for more on using these two tools together.
Moisture Detection and Origin Analysis Using infrared thermography along with moisture meters and other testing equipment, it is pretty easy nowadays to locate areas that may be wet or damp quickly and cost-effectively, which are not visible to the naked eye. For example, a basement that has flooded may appear to be dry after air-movers have been used, but unless the proper number of air-movers were used, along with the placement of them, AND use of properly-sized dehumidifiers, the moisture that was once present on the floor may remain behind the drywall and within other fibrous materials where it can remain hidden for days, weeks, or even months, until mold and/or mildew begins to form. With infrared analysis, we can quickly and easily see if, in fact, the moisture has been eliminated, saving thousands in potential repair costs associated with drywall replacement, mold and mildew remediation, etc. While an infrared camera does not specifically detect moisture itself, it does detect differences in temperature. When a material becomes wet and saturated with water, its temperature will be cooler than the surrounding areas because water takes longer to warm up than say, wood or drywall. In order to verify that what the IR camera is seeing is, in fact, moisture, we use a moisture meter or moisture probe to make sure. When IR is used during the initial inspection for water damage, the damaged areas can be quickly determined and marked for replacement, if needed, potentially saving hundreds or thousands of dollars in unneeded repair and replacement costs for materials and labor. Before you rip out all the drywall you THINK is damaged, call us to see if it is really necessary!
Flat roofs are everywhere. Most commercial, institutional, and industrial roofs are flat roofs. Thousands of millions of square feet of flat roof are installed each year. Flat roofs are expensive to install ($4 to $6 per SF or more for a new roof) and replacement roofs can cost as much as $8 to $10 per squeare foot when disposal costs of the old roof are included.
Flat roofs are highly susceptible to leaks and water damage. Once a leak begins, it will saturate the insulation beneath it, diminishing the R-value of the ceiling's insulation and adding unneeded heating and cooling costs to a building. Luckily, IR is a very quick and easy way to locate flat roof leaks! Detecting the leak must be done at nighttime, typically a couple hours after the sun goes down. There also must be at least two or three days of no rain before the test can be completed. The pictures below illustrate how the IR camera detects moisture in a built-up-roof system (BURs).
The losses from premature roof failure run into the billions of dollars every year. These dollars are lost, and are not available to support or extend business operations. The primary costs associated with roof failures include the following:
Professional energy audits can go into great detail, depending on the extent to which the homeowner wants information on their energy consumption. The Building Performance Group conducts Home Performance Inspections using IR cameras, blower-door testing equipment to determine air-leakage, and specialized software to quantify certain energy-consumption characteristics. The auditor first examines the characteristics of the house or building (i.e., wall area, number and size of windows, type of siding, type of construction, etc). The auditor will then ask questions about the occupants' behavior, including:
The energy auditor will then do a room-by-room examination of the residence, as well as an examination of past utility bills. Finally, a report can be generated, for an additional fee, that offers cost-effective improvements that can be done to improve the overall efficiency of the home or building. There are many simple online websites that allow you to conduct a very basic audit of your home yourself, although without a professional actually seeing your home and using diagnostic equipment, the results will be very general and many things can be missed. For online energy audits, visit: Home Energy Saver
Home Energy Ratings - Energy Star Certification
There are a lot of builders today that are currently building energy-efficient homes and don't realize they could already qualify for the Energy Star Homes program. Federal incentives to build Energy Star certified homes include a $2,000 tax credit to the builder, or homeowner if they are acting as general contractor. The Energy Star Homes certification is actually pretty straight-forward. A certified Home Energy Rating System (HERS) rater takes blueprints and specs for a new home and enters the surface area details into a software program called Rem/Rate. Rem/Rate is the nationally approved home energy rating software chosen by RESNET. Secondly, the HERS rater does a Thermal Bypass Check of the insulation and air-sealing work before the drywall is installed. The insulation must be installed completely, with no gaps, voids, or compressions anywhere in the thermal envelope. Click here for an official copy of the Thermal Bypass Checklist. Lastly, the HERS rater conducts a series of diagnostic tests using a blower-door and a duct-blaster, as well as an infrared camera. The air leakage in the house must be minimal, as well as the duct leakage throughout the HVAC system - as designed in the Rem/Rate report. The duct leakage is limited to 6 cfm/100 SF of living space. After the house has been confirmed to perform as intended, the Rem/Rate report with diagnostic figures is sent to the Energy Star Homes Provider, and is checked to ensure complete accuracy. For more, please visit the official Energy Star website, or call Eric at 502-409-5979 to schedule an appointment. You can also email us to receive a free PDF that walks you step by step through the HERS rating process. |
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ContactPlease call (502) 409-5979 or email us at info@greenbuildingpg.com for more information on our services or to schedule a live consultation. |
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been readily available to the majority of the general public. The initial cost of the first few generations of cameras were too costly for most contractors and business to justify the investment, but recently these costs have been greatly reduced and many good-quality cameras are now available for less than $10,000.
Leader in Thermal Imaging Infrared Cameras". They are lightweight, easy to use, powerful tools for discovering a wide array of issues, not only in buildings, but also electrical, mechanical, industrial, equine, and many other applications as well.
A blower-door is a very useful building diagnostic tool that is used to quanitfy air leakage and differences in pressure in homes, offices, and any other heated and cooled buildings. While the blower-door is running, a pressure-pan can be used to test for duct leakage in specific supply and return registers throughout the building. (Pic below shows a pressure-pan test)
The rule of thumb used among building-performance professionals to judge "tightness" or "leakiness" of a building, with respect to other similarly-sized buildings is air-changes per hour (ACH). It is the total volume of air in a home that is turned over in one hour. Tightly constructed homes may have an ACH of 0.25 to 0.35 ACH, or even less.
Throughout the day the sun's heat will warm the surface of the roof. The areas which contain water beneath the surface will warm up much slower than the rest of the roof area. The reason for this is because water has a higher thermal capacitance than the surrounding insulation materials, and absorbs heat at a much slower rate.
At nighttime, after the sun goes down and the roof starts to cool off, the areas where moisture is trapped beneath will still be releasing the heat that was stored all day from the sun and can then be easily visible as "hot spots" when compared to the rest of the dry roof areas.
Once the roof leaks have been detected, the area is marked off with spray paint so that a roofing contractor can easily find and repair ONLY the areas that are damaged. This can ultimately save the building owner THOUSANDS of dollars in unneeded roof replacement costs!
The picture to the left shows an example of what the IR camera sees at nighttime. The difference between hot and cold, or wet and dry in this case, is very clear. There is no disputing this visual evidence.
