Understanding infrared thermography: The role of thermography in detecting energy inefficiency February 2013
White Paper: Understanding infrared thermography The role of thermography in detecting energy inefficiency __________________________________________________________________________________________________ The increased nationwide focus on energy efficiency has prompted an inevitable boom in technology for the ‘green market’.
While many of the services in this crowded arena promise much but offer little, infrared thermography is one area that’s seen a significant increase in popularity in recent years, with projects ranging from large-scale commercial developments to single domestic dwellings. Recently, for instance, Heathrow Airport invested in four infrared cameras as part of its commitment to reducing CO2 emissions, while an increasing number of universities, hospitals and local authorities are also using the technology to assess their property stocks for abnormalities resulting in energy loss. Thermography works by measuring a building’s surface temperature using noncontact infrared cameras. The thermal images produced display regions of varying 1|P a g e
temperatures in different colours, thus allowing property owners to see exactly where they are losing heat and, as a result, money. Heat sensed by an infrared camera can be quantified allowing for evaluation of the severity of the problems. It’s most commonly used to identify missing or damaged insulation, thermal bridges and areas at risk from mould and condensation. The information provided by the images is enough to accurately identify the key areas a property owner must address to improve energy efficiency, be it draft proofing or replacing doors and windows, or the installation of insulation in cavity walls, solid walls or lofts. So just how big a role does thermography have to play in the UK’s quest for energy efficiency? In light of the April 2018 deadline of the UK Energy Act, more and more property owners are assessing the technology’s benefits and drawbacks in their search for an innovative ‘game changer’ capable of helping them approach the future with confidence.
The pros of infrared thermography Non-invasive Using traditional techniques to assess a property’s energy efficiency is frequently a cumbersome and destructive process. Be it the drilling of minor holes or the erection of unsightly scaffolding scaling your building, the inconvenience of traditional procedures can prompt complaints and legal issues as well as cause significant strain on landlord/tenant relationships. Most gallingly, in many cases such measures are poorly targeted and thus completely unnecessary. The non-invasive and safe nature of infrared thermography not only ensures surveying can be carried out with no disruption to a building’s occupants, but also that any future works are, in fact, essential. 2|P a g e
Providing the infrared surveyor is completely impartial, clients can proceed with, and prioritise, refurbishment programs safe in the knowledge that disruption will only occur for works that are needed to safeguard the building’s long term future. Accuracy Accuracy is a cornerstone of thermographic analysis. While traditional surveying relies on informed but ultimately subjective assessments, the highly visual nature of a thermal image ensures nothing is left to guesswork. In this example of a surveyed flat roof, the red and yellow area is saturated insulation and the white box is an air conditioning unit. The client is given undeniable evidence of the cause of the problem, empowering them to take action and perhaps even file an insurance claim – all from a simple, non-invasive image. The visual nature of the findings means clients do not have to be technically minded to understand the root of their building’s problems. Given many property owners do not where to begin with energy efficiency and are left overwhelmed by ever-changing legislation and funding mechanisms, infrared thermography can help to provide them with an excellent starting point and clear vision of the direction they must take. On the flipside, the technology is increasingly being used for BREEAM and Quality Assurance assessments. By presenting visual evidence of the condition of a building or product ahead of handover, a company can help protect itself against frivolous complaints in the future. Speed It takes an average of three seconds to capture a thermal image capable of revealing a property’s heat loss. This is one of the reasons the technology is particularly appealing to large organisations, giving them scope to assess significant property stocks and large buildings in a timescale that would have been logistically impossible
3|P a g e
in the past. The non-invasive nature also aids the efficiency of the process, given a buildingâ€™s occupants do not need to be warned of work in advance. Thermographic analysis of a building can be captured without inconvenience, allowing the surveyor to collect images quickly ahead of moving onto the next property. The speed of surveying is particularly beneficial when an initial analysis fails to uncover the root of a problem. While this would represent a significant waste of time and resources with more traditional techniques, surveyors with infrared cameras can simply move on and begin photographing another area of the property stock. Safety The non-contact nature of thermographic analysis gives it a clear advantage over traditional methods when it comes to assessing fragile properties with limited access. Infrared cameras can capture all the information they need from distance and many thermography specialists have invested in vehicles with pneumatic masts to aid with the assessment of out-of-sight regions. This ensures every inch of a property can be assessed without compromising the safety of the surveyor or those within the vicinity of the building in anyway. Cost Effectiveness The process of energy assessment would traditionally involve the hiring of highly skilled but expensive operatives conducting time consuming and destructive tests. Relatively speaking, thermographic surveying is a highly cost effective measure given its efficiency and non-destructive nature. Furthermore, property owners can be certain of the â€˜main offendersâ€™ in terms of energy inefficiency and ensure capital expenditure is only used to address the most pressing issues.
4|P a g e
The cons of infrared thermography Environmental Constraints Thermography takes an extremely precise approach to energy efficiency and as such, accurate assessments can only be carried out in specific conditions. For instance, you cannot survey unless there is a temperature difference of 10C (minimum) between the inside and outside of the building. It’s also absolutely imperative that conditions are dry. Capturing images of a cool, wet building will fail to highlight areas of missing and damaged insulation and greatly limit the areas of heat loss that are revealed. Wind is also problematic, as high speeds will simply result in energy loss blowing away before it can be accurately measured. That means surveys cannot be carried out unless the wind speed is less than 10m/s. And finally, it’s always best to work at night in order to ensure factors such as absorption of heat from the sunlight and the interior of the building itself are taken out of the equation in the survey’s findings.
Misleading Results Impartiality is vitally important when it comes to infrared thermography. As much as a picture may be worth a thousand words, simply adjusting the level and span settings of an infrared camera can result in hugely misleading thermal images capable of telling any story the person behind the camera wishes. That could be suggesting a defective building is in perfect working order or vice versa; unless the property owner has a thorough understanding of how the technology works, they may well end up approaching the future in an entirely inappropriate way. Consequently, it’s important to progress with organisations that have no vested interest in any product or service. 5|P a g e
Camera Cost Although a dramatic decrease in camera prices recently may mean some major organisations have the budget available to invest in the technology, it remains beyond the reach of the average property owner/business. A standard handheld camera will cost in excess of £8,000 meaning those interested in a thermographic survey should find a trusted partner to move forward with.
Conclusion Infrared thermography is a ‘game changer’ that eliminates guesswork at a time when refurbishment decisions, more than ever, have to be the right ones. While it’s not without its drawbacks, the technology is revolutionising energy efficiency assessments in the three areas that matter most – speed, accuracy and cost. Providing the surveyors are impartial and the conditions are suitable, it represents the most appropriate way for the UK’s overwhelmed property owners to establish their starting point, as well as the direction they must head in to ensure their property stock’s continued compliance with ever-developing energy legislation.
Contact Drumbeat Energy Limited - Regent’s Place, 338 Euston Road, London NW1 3BT Telephone: 020 7078 4103 Email: email@example.com Website: www.drumbeatenergy.com
6|P a g e