What is Airtightness Testing?
A building that complies with recommended levels of air leakage has a guaranteed performance.
An Air Leakage Test is carried out after the external fabric has been completed to confirm (or otherwise) that the building achieves the minimum air leakage standards set by the building’s designers. The continuity of the air barrier is fully tested, and any areas of failure can be identified. This allows any remedial work necessary to be carried out before retest.
Air leakage measurement on a new building is really the end of the process in ensuring a high-performance, low-leakage envelope. It follows work at the design stage to ensure continuity of the air barrier around openings and at all joints in the building fabric. During construction, quality control must be maintained so that the design details are reproduced on site. Finally, the building is tested to confirm that the specified standards have been achieved.
What is Air Leakage?
Air Leakage (or infiltration) is the flow of outside air into and out of a building. It is not planned by the designers and is due to imperfections in the building ‘envelope’ or outer skin.
It will typically take place through:
- Joints, gaps, and cracks in the construction
- Gaps created where the structure penetrates the outer skin of the building
- Cracks around door and window openings
- Gaps where services enter the building
Air leakage will have detrimental effects on the building’s thermal performance, comfort levels, and energy efficiency.
What qualifications are required by testing organisations in order to carry out airtightness testing on commercial and residential buildings?
BET is accredited by INAB to carry out testing to ISO 17025, what does this mean?
BET is accredited as a testing laboratory by INAB (the Irish National Accreditation Board). The term accreditation is often misunderstood, often by those who claim ‘to be accredited’ without having any understanding of what it really means!
Accreditation is only awarded in Ireland by INAB and requires a company to operate and maintain an ISO compliant quality management system. The process of gaining accreditation is not for the light-hearted and involves the development and practice of many technical and managerial procedures to ensure complete traceability and quality of the test results. Our quality management system covers all aspects of our testing activities, including calibration and maintenance of equipment, training of staff, and the way that we deal with contracts and our customers.
The importance of providing a technically excellent service to our clients has always been at the centre of what we do and the need for us to establish complete traceability was a clear company objective from the very beginning.
An accredited company has been assessed against internationally recognised standards to demonstrate competence, impartiality, and performance capability. This process is continuous to ensure that high standards of quality are always maintained.
Using an accredited company gives you and your clients the confidence and traceability necessary in the environment of today’s construction industry.
Specifying a test becomes more straightforward if you simply specify that an INAB accredited specialist with a proven track record is required to carry out the Airtightness Test.
What is the difference between ISO Accreditation and NSAI Certification?
ISO Accreditation to 17025 is the highest standard achievable for an Airtightness Testing Organisation. NSAI certification certifies a testing organisation to test in compliance with I.S. EN 13829 ONLY. ISO accreditation enables the testing organisation to fully comply with the aforementioned I.S. EN 13829, CIBSE TM 23 and ATTMA TS1 & TS2. A testing organisation cannot test in full compliance with the ATTMA unless it has achieved accreditation to ISO 17025.
The second page of ATTMA TS1 & TS2 states:
“For a testing organisation to show full compliance with this standard, they should have suitable third-party monitoring systems in place. This is demonstrated by either holding building air leakage testing UKAS accreditation (INAB Equivalent) for organisations in line with BS ISO:17025:2005.”
In conclusion, NSAI certification enables organisations to become certified to test in accordance with I.S. EN 13829 only. ISO accreditation enables organisations to certify the actual building in accordance with I.S. EN 13829, CIBSE TM 23, and ATTMA TSL1 & TSL2.
What specification should I choose for my building?
The recommended airtightness specification for your building depends on its type and use. By good design, attention to detail, and good levels of quality control on site, 10 m3/(hr.m²) for commercial buildings and 7 m3/(hr.m²) should be achieved with minimal or no additional expense. In other words, if we do what we’re supposed to be doing anyway!
The ATTMA offer guidance on best practice and good practice guidelines. BET has written specifications for some of Ireland’s leading architectural, service engineering firms, developers, and government organisations.
What qualifications are required to fully comply with the ATTMA?
For a testing organisation to show full compliance with ATTMA, it is required to be ISO accredited to 17025 and therefore, it should have suitable third-party monitoring systems in place.
BET is accredited as a testing laboratory by INAB (the Irish National Accreditation Board). Accreditation is only awarded in Ireland by INAB and requires a company to operate and maintain an ISO compliant quality management system. The process of gaining accreditation is not for the light-hearted. It involves the development and practice of many technical and managerial procedures to ensure complete traceability and quality of the test results.
Our quality management system covers all aspects of our testing activities, including the calibration and maintenance of equipment, training of staff, and the way that we deal with contracts and our customers.
What can a thermographic survey do for you?
Thermographic surveys can be conducted to identify cold bridging and discontinuity in or sub-standard levels of insulation. Thermographic photography can also be useful in identifying air leakage paths when more cost-effective methods (tracer smoke) cannot be used.
BET’s thermographic engineer is Level III qualified and uses camera equipment recognised as the highest quality available.
Thermography requires a high level of skill, experience, and training to conduct surveys effectively and interpret images correctly.
The standard of the camera used is also critical. Certain conditions must exist if thermographic observations are to give an accurate view of air leakage and thermal bridging in the building fabric.
What is a level 1 thermographer qualified to do?
This is the industry standard for thermographers. It is the basic level, and certification is seen as acceptance that the operator can use a camera and perform basic analysis. A level 1 Thermographer should be working under the guidance of someone certified at a higher level, and they should be following procedures prepared by a Level 3. They should be told which measurement technique they should be following.
Level 1 thermographers are able to collect data, take images, and understand how to reduce potential errors. Sometimes they are limited to taking images and restricted from writing reports. In other cases, they will only work qualitatively. A Level 1 thermographer should have received 32 hours of training and should have 400 hours of documented experience over a 12-month period.
They are NOT permitted to carry out a building survey in accordance with BREEAM.
Under the PCN scheme, a level 1 thermography certification is “general”, meaning there is no specialisation.
What is a level 2 thermographer qualified to do?
A level 2 thermographer is someone with a higher degree of training and experience. They understand more about the camera and how it works, and the physics related to thermography. Level 2 thermographers are better placed to specify thermography equipment and to supervise Level 1 thermographers.
Like Level 1 thermographers, Level 2s should be following procedures developed by a Level 3. Usually, they are able to perform and direct IR thermography according to established procedures. They are able to select the correct measuring technique for themselves, they can write reports and can work quantitively.
A Level 2 thermographer should have received an additional 32 hours of training, and should have 1200 hours of documented experience over a 24 month period.
Under BREEAM, a level 2 PCN certified civil thermographer is permitted to carry out thermography on a building.
PCN certification at Level 2 introduces specialisation, so thermographers may be certified as Level 2 Electrical, Level 2 Mechanical, or Level 2 Civil. Thermographers may have more than one area of specialisation.
What is a Level 3 thermographer qualified to do?
Level 3 thermographers undertake the highest level of thermography and enjoy the most freedom. Since they develop the procedures, they are free to develop new ones as and when required. They usually understand more about the laws of physics as they relate to thermography.
Level 3s often get involved with machine prognostics and with preventing problems from re-occurring at the highest level through recommending thermodynamic corrective actions. They are able to perform and direct all types of thermodynamic measurements and analyses.
Level 3s are qualified to establish thermography programmes, determine acceptance or failure criteria, interpret codes and standards, and perform prognostics. They are also usually familiar with other test methods and can recommend supplementary tests.
A Level 3 thermographer should have received an additional 32 hours of training and have 1920 hours of documented experience over a 48-month period.
A PCN Level 3 thermographer in civil applications is permitted to carry out a survey for as part of BREEAM.
Under PCN, thermographers may be certified as Level 3 Electrical, Level 3 Mechanical or Level 3 Civil.
Thermographers certified under the PCN scheme may have more than one area of specialisation.