Thermal inspection
June 1st 2005

Since April 2002,Part L2 of Building Regulations have required all buildings with a floor area in excess of 1000m2 to be constructed and tested for air permeability.

Introduced in response to the urgent need to save energy and reduce global emissions, this is first legislation to prevent actively, the construction of leaky buildings Good insulation must be designed, specified and its performance proven.An important technique used to confirm the presence and continuity of thermal insulation to prevent energy loss, is thermography.

Any object that is not transmitting, generating or absorbing heat will take on the surrounding air temperature. So cold air leaking into a building – or missing insulation on a heated building – will cause cold patches on the wall, floor or ceiling. Conversely, warm air leaking from a building will cause warm patches on the outside of a wall or roof.

Thermal imaging cameras are designed to enable the user to see and measure these temperature differences through a viewfinder or an LCD display.

All objects warmer than absolute zero emit IR radiation and the camera can measure this heat emission very precisely via many thousands of temperature measurement points.

FLIR Systems has just introduced a thermal imaging cameras specifically for building inspection.

Called the ThermaCAM B20, the camera also incorporates automatic dew point identification to determine areas susceptible to condensation and mould-growth.

Thermography is also becoming increasingly important in industry as companies strive to reduce energy use in line with the Kyoto Protocol. Heathrow Airport is a prime example and spearheading its regime is energy manager,Andy Watson. Under his stewardship, Heathrow Airport has just invested in four FLIR Systems ThermaCAM Pand E-series thermal imaging cameras.

“We are currently in the throes of thermally inspecting all the buildings at Heathrow Airport,” Andy Watson explains.“ We are primarily looking for badly insulated areas so that we can prevent heat loss and save energy. Another target is locating the points where cold air is coming into buildings.” In addition to studying building fabric, the cameras are also being integrated into a predictive maintenance programme for all plant. System failures can of course be very costly. For example if a baggage handling system fails, compensation may be due to the affected airline company. However, Andy Watson’s brief goes beyond damage limitation. His principle concern is driving down energy consumption on behalf of the British Airport Authority.

He continues,“In an electrical system for example, a hot connection is constantly dissipating energy. The same is true for conveyor belts and other mechanical systems.

Generally a faulty system will generate three times more heat than one that is working optimally. This gives us tremendous energy saving potential.” For Heathrow Airport, the daily cost savings it is making are a bonus as the cameras had paid for themselves even before they were properly put to work.A known leak in an underground pipe was the subject of an early survey. The pipe in question, used to transport steam to heat airport buildings, is located very close to Terminal 1 and under a very busy road As the ThermaCAM was able to determine the exact location of the leak, the need to dig up the road between two inspection pits spaced at 60 metres apart, was averted. A neat hole above the leak was the only requirement. This one find saved Heathrow Airport over 400,000 euros in maintenance costs and of course contributed to more energy savings.

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