1、Thermal performance of buildings - Qualitative detection of thermal irregularities in building envelopes - Infrared method (IS0 6781:1983 modified) The European Standard EN 13187:1998 has the status of a British Standard ICs 91.120.10 BS EN 13187:1999 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERM
2、ITTED BY COPYRIGHT LAW - STD-BSI BS EN 13187-ENGL 1999 W Lb24bb7 0757LbU bbL W direction of the Engineering Sector Committee, was published under the authority of the Standards Committee and comes into effect on 15 March 1999 Amd. No. O BSI 03-1999 BS EN 1318R1999 Date Text affected National forewor
3、d This British Standard is the English language version of EN 131871998. The K participation in its preparation was entrusted by Technical Committee RHE9, Thermal insulating materials, to Subcommittee RHE/9/2, Thermal properties of insdating materials, which has the responsibility to: - aid enquirer
4、s to understand the text, - present to the responsible European committee any enquiries on the - monitor related intedonal and European developments and promulgate interpretation, or proposals for change, and keep the UK interests informed; them in the UK A list of organizations represented on this
5、committee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “Inkrnational Standards Correspondence Index“, or b
6、y using the “Find“ facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a conmt Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunit
7、y from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 12, an inside back cover and a back cover. ISBN O 680 30922 3 I I STD-BSI BS EN 13L87-ENGL 1777 H Lb24bb9 0757LbL 5TB H EUROPEAN SIANDARD NORME EUR0PEE”E EUROP Evalu
8、ation of temperature anticipatediactual distribution from temperature distribution thermal image Comparison of b) ascertaining whether this surface temperature distribution is “abnormal“, i.e. if it is due, for example, to insulation defects, moisture content ardor air leakage; c) if so, assessment
9、of the type and the extent of defects. In order to determine whether the observed variations in the thermal insulation properties are abnormal, the thermograms obtained are compared with the anticipated temperature distribution over the surface, determined by the design characteristics of the buildi
10、ng envelope and by the environment at the time of examhation. The anticipated temperature distributions can be determined by means of “reference thermograms“ (see 6.3 and annexes A, B and C), calcuiations or other investigations. This determinati on is based on drawings and other documens relating t
11、o the extemal envelope and to the heating and ventilation system of the building under investigation. The general procedure for the interpretation of thed images is represented schematidy in Figure 1. 1 I I - r I Casual mechanisms leading I to thermal irregularities of 1 similar structures from them
12、o- I examination of the building O BSI 03-1999 6 Irrared radiation sensing system The infrared radiation sensing system shall comprise. a) an infrased radiation sensor, operating at a wavelength between 2 pn and 12 km, which can sense apparent radiance temperatures of interest with sufficient resolu
13、tionl); b) a device which renders visible and displays, in the form of a thermal image, the apparent radiance temperature over the surface being examined; e) a device which makes it possible to record the thermal image and, if relevant, measured digital data; d) a means of establishing temperature l
14、evels on the surface under examinati on. During the test period, no significant drift in the infrared radiation sensing system shall occur. 6 Thermographic examination 6.1 General test requirements In order to defuie the actual test requirements, and in particular the side of the building envelope (
15、outdoors or indoors) from which the thermographic examination is to be perormed, the following factors need to be considered a) the specifications and capabilities of the thermographic equipment; b) the characteristics of the building envelope, i.e. the respective types and locations of heating syst
16、ems, stmcturd elements and insulating iayers; e) the radiative properties of the surface, e.g. the cladding mate- d) climatic factors; e) accessibility for easy inspection; f) influences of the environment; g) other factors of importance. The temperature difference across the envelope shall be suffi
17、ciently large to permit the detection of thermal irregularities. For ease of interpretation, the thermographic examination should preferably be carried out with constant temperature and pressure differences across the envelope. (The interpretation of thermograms taken under non-steady state conditio
18、ns requires a higher degree of expertise and knowledge of building physics.) This implies, among other things, that the test shall not be canied out when the outside or inside air temperature is liable to vary considerably, or when the structure is exposed to direct solar radiation, or when the wind
19、 varies markedly. These general requirements shall be considered when a thermographic examination is camied out. The actual requirements may be varied according to the thermal properties of the building envelope under examination Page 5 EN 131871998 and the characteristics of the infrared radiation
20、sensing system used They may b) the regularity and incidence of colder or warmer sections, for instance over studs and corners; c) the location of the contours and characteristic shape of the colder or warmer sections; d) the measured difference between the “normal“ surface temperature of the consts
21、uction and the temperature of the selected colder or warmer sections; rregukities in the appearance of a thermogram often indicate a defect in the building envelope. The appearance of a thermogram relating to a construction with a defect may vary considerably. 6.4 Examples of pattern characteristics
22、 a) Air leakage (often at joints and junctions) in the building envelope often produces irreguiar shapes with uneven boundaries and large temperature VariationS. b) Missing insulation produces reguiar and well defined shapes not associated with features of the building dmcture. The defect area has a
23、 reiatively even temperature variation. c) Moisture present in the structure normally produces a mottled and diffuse pattern. Temperature variations are not extreme within the pattern. The type of defect shall be determined. This may be done by calculation, by other investigations, from experience o
24、r by comparing the actual thermograms with reference thermograms for structures with known thermal insuiation defects and air leakages of various kinds. Such determinations shall be thoroughly substantiated in the thermographic report. For those parts of the building envelope in which the presence o
25、f thermal insulation defects and air leakages have been detected, the type and the extent of each defect shall be subject to a brief anaiysis. NOTE The results of the test can be checked by disassembling the part of the building envelope suspected ta be defective, and by subjecting it to visuai exam
26、ination. Other supplementary investigations may include heat flow measurements and pressurization tests. O BSI 03-1999 7 Thermographic report 7.1 Report on testing with an IR camera The report shaU include: a) a description of the test with reference to this standard and a statement, that testing wi
27、th an IR camera has been performed, name of the client and full address of the object; b) brief description of the construction of the building (this information shall be based on drawings or other available documentation); e) type(s) of surface materid(s) used in the structure and the estimated vai
28、ue(s) of emissivity of this (these) material(s); d) orientation of the building with respect to the points of the compass shown in a plan, and description of the surroundings (bddings, vegetation, landscape, etc.); e) specification of the equipment used, including make, model and serial number, f) d
29、ate and hour of test; g) outside air temperature. Give at least the minimum and maximum values observed, i) during the 24 h prior to the start of the examination and, U) during the examination; h) general irormation about solas radiation conditions, observed during the 12 h prior to the start of the
30、 examination and during the examination; j) precipitation, direction of the wind, and velocity of the wind during the examinatioq k) inside air temperature and air temperature difference across the envelope during the examination; 1) difference in air pressure over the leeward and windward side, whe
31、never necessary for each storey; m) other important factors influencing the results, for example rapid variations in weather conditions; n) statement of any deviations from relevant test requirements, o) sketches andlor photographs of the building showing the positions of the thermograms; p) thermog
32、rams indicating temperature levels obtained fkom the test, showing parts of the building where defects have been detected, with indications of their respective positions, and the position of the IR camera with respect to the measurement target, and with comments on the appearance of the thermal imag
33、es; if possible with reference to parts of the building envelope with acceptable performance; Page 7 EN 131871998 q) identification of the parts of the building examined r) results of the analysis dealing with the type and the extent of each construction defect which has been observed2). Relative ex
34、tent of the defect by a comparison of the defective part of the envelope to similar parts throughout the building s) results of supplementary measurements and investigations; t) date and signature. 7.2 Report on simplified testing with an IR camera The report shall include: a) a description of the t
35、est with reference to this standard and a statement, that simplified testing with an IR camera has been performed, name of the client and fuli address of the object; b) brief description of the construction of the building. (This information shall be based on drawings or other available documentatio
36、n.); cl - d) - e) - f) date and hour of test, 9 - h) - j) - k) inside air temperature and air temperature difference across the envelope during the examination; 1) difference in air pressure over the leeward and windward side, whenever necessary for each storey; m) other important factors influencin
37、g the results, for example rapid variations in weather conditions; n) statement of any deviations from relevant test requirements; 0) - Pl - q) identification of the parts of the building examined; r) type, extent and position of each observed defect?); s) results of supplementary measurements and i
38、nvestigations; t) date and signature. 2, According to 6.4.3 of EN 45001: 1989, this item shall not include any statement of whether these defects require measures to be taken, or whether they can be accepted. Such statements may be given in a separate letter. 3, According to 6.4.3 of EN 45001: 1989,
39、 this item shall not include any statement of whether these defects require measures to be taken, or whether they can be accepted. Such statements may be given in a separate letter. O BSI 03-1999 Page 8 EN 13187:1998 for the production of reference thermograms. Annex A (lliformative) Reference therm
40、ograms A.l Reference thermograms obtained from field measurements on actual buildings Thermograms produced by field measurements on actual buildings can be used as reference thermograms, provided that the characteristics of the buildings under examination, the workmanship, and the test conditions at
41、 the time of examination are weil known and documented. A.2 Reference thermograms produced in a laboratory Reference thermograms can be produced in an and b) as one or severai isotherm images which clearly exhibit the temperature distribution that is characteristic of the defect under examination. E
42、xamples of reference thermograms of a typicai envelope with no defects (see Figure Al) are shown in annex B. O BSI 03-1999 Page 9 EN 1318R1998 I Figure A.2 - Division of the typical envelope into frames as shown in annexes B and C Il I II II II II Il I II II I Figure A.3 - Positions of deliberate de
43、fects shown on the thermograms in annex C O BSI 03-1999 STD-BSI BS EN L3387-ENGL 1999 H 3b24bb7 0757370 5iiO H Page 10 EN 131871998 Annex B (informative) Examples ofthemof- recorded on a stud wall “with no defects” Minerai wool, 120 mm thick. lmperature difference (inside-outside), Si - 6, = 26 OC.
44、Pressure difference (inside-outside), pi - pe = -50 Pa The mows indicate the isotherms corresponding to the temperatures which are shown on the relative temperature scale in each image. Under each isotherm image, the difference in temperature (A6) between the is stated in Celsius* O BSI 03-1999 Page
45、 11 EN 13187:1998 Annex C (informative) ExmPles oftherno= recorded on a stud wall containing deliberate defects Mineral wool, 120 mm thick. kmperature difference (inside-outside), Si - 8, = 26 OC. Pressure difference (inside-outside), pi - p, = -50 Pa The mows indicate the isotherms corresponding to
46、 the temperatures which are shown on the relative temperature scale in each image. Under each isotherm image, the difference in temperature (AO) between the isotherms is in dees celsius 1 50 2 100 5 200 10 500 20 1001 O BSI 03-1999 Page 12 EN 1318R1998 Annex D (informative) Example of a set of test
47、requirements The test requirements in this annex are adapted to meet the specific climatic conditions and building technology of Scandinavia. Special national conditions may justify other sets of test requirements in other lTgiOW. For Scandinavian conditions, the following test requirements are like
48、ly to ensure approximate steady state conditions for a lightweight building stsudure4), when the thermographic examination is to be carried out from the inside. a) For at least 24 h before the start of the examinaiion, the external air temperature shall not vary by more than f10 “C from the temperat
49、ure at the start of the examination. For heavy structures with a iarge thermal mass, special consideration has to be given to the effects of heat storage. b) For at least 24 h before the start of the examinati * on, and during the examination, the air temperature difference moss the building envelope shall not be less than the numerical value of 3/U, where U is the theoretical value of the thermal transmittance of the buildllig element in W/(m2.K), but never less than 5 OC. c) For at least 12 h before the start of the examination, and during the examination, the surf
