1 Thermography of Buildings Stacey Ward - BSRIA Instrument Solutions - - Sales Manager -

2 Benefits of thermography  Quick inspection  Results clearly shown in pictures  Shows precise location of fault  Shows severity of fault  Shows compliance with regulations  Improves build quality

3 Limitations  Needs temperature difference  Needs clear view of surface  Building surveys limited by  Wind  Rain  Past temperatures  Not an accurate heat loss assessment  Cameras are not cheap  They are more affordable than they were  And you can hire by the week

4 Typical applications  Building insulation and air leakage  Building energy efficiency  Building moisture surveys  Pipework  Electrical installations

5 Building insulation and air leakage  Meet requirements of Building Regulations Part L ‘reasonably continuous thermal insulation’  Show air leakage paths to help re-sealing

6 Air tightness testing

7  Testing to include effect of leakage through the floor  Can include smoke testing  Can include both pressurisation and depressurisation tests

8 Locating air leakage

9

10 Understand how thermography is affected by:  features of buildings,  surface properties  acceptable temperatures,  understanding the environment you are working in,  obtaining a good image,  differentiating between anomalies  faults and normal temperature variations.

Thermal Imaging 11  10 o C temperature difference for at least 4 hours.  Dry, no sun, wind speed < 8m/s.  320 x 240 pixels minimum infrared resolution.

12 Features of buildings important for Thermography  Masonry or framed construction  Glass  Rainscreen cladding  Air outlets  Light fittings  Heaters

13 Framed construction - roof

14 Framed Construction - walls

15 Glass not transparent

16 Heat sources under windows

17 Acceptable temperatures  Need to have sufficient temperature difference to detect defects  Normally means at least 10°C between inside and out

18 Understand the environment  Heat exchange by radiation and convection  Sky can be –50°C  Sunshine can raise surface temperature to +70°C in the UK  Set the ‘ambient temperature’ in your camera  Wind can eliminate surface temperature difference in external surveys

19 Effects of cold sky

20 In buildings with no heating

21 Solar gain can be used to an advantage

22 Obtain a good image  At survey time:  Subject  Distance/resolution  Focus  Broad temperature range  In analysis  Correct temperature range  Correct environmental settings

23 Zoom in to focus

24 Zoom out for full image

25 Benefits of high resolution

26 Defect, anomaly or feature

27 Cold bridges - steelwork

28 Thermography locates air leakage behind plasterboard

29 Thermography locates air leakage behind plasterboard

30 Extract from the thermographic report Note: this is inside of building but outside was warmer so the poorly insulated areas show up as warm

31 Case study 1  retail building, 130x75 metres and 6-9 m high  interface detail left a 73mm strip uninsulated  =30 square metres of cladding with a U value of 3.5W/m²K instead of 0.35W/m²K.  would require an extra 2kW of heating  nearly 8000 kWh a year extra heating  cost of over £600 a year  generating nearly 4000kg of additional CO 2.

32 Building fabric thermography  Construction defects

33 Building fabric thermography  Construction defects  Remedial action

34 Case study 2  Traditional brick - cavity - block wall  Note surface temperature variations  Effect of missing cavity bat  Effect of mortar joint  Condensation  Mould growth

35 Mortar in poor structure U value 1.41

36 Mortar in poor structure U value 1.41

37 Energy surveys  Temperature differences between similar areas  Hidden features  Buried services

38 Wasted Energy ?

39 Roof Moisture  Warm area shows moisture in roof structure

40 Roof moisture survey  Relies on change in temperature  Survey after sunset on a sunny day  Avoid surface water or debris  Moist insulation has high thermal capacity  Stays warm for some time after sunset  Sharp contrast with dry insulation

41 Underfloor heating  Warm areas shows underfloor heating pipes

42 Underfloor heating  What can go wrong?

43 Chilled ceilings Cold areas are working, warm are not

44 Busbars

45 What to inspect  Critical items  Where no other method –don’t forget conventional test & inspection  Consider failure modes  Cost / benefit  Access / safety

46 UPS Battery Systems

47 Electrical thermography to avoid fires

48 Commissioning lighting panel

49 Summary  Thermography has almost limitless applications  Quick and easy way of checking quality and condition  New regulations will increase use  Standards are being established  Training and Certification essential  BSRIA at the centre of development

50 Thanks! Any questions?     