Air pressure q50 test
The q50-value over one hour is used to describe the air leakage (or air infiltration rate) of a building envelope at a pressure difference of 50 Pascals (Pa). This standard is related to the rate that air infiltrates the whole envelope of a building when doors and windows are closed thus the volume is calculated to include everything within the envelope or the air tightness line.
This is measured through a q50 pressure test which is carried out by closing and sealing doors and windows and installing a door blower to create a pressure differential of 50 Pa (equivalent to a 5 mm water column) between the inside and outside, to measure the air leakage. The standard (or q50) and the UK building regulations requires a test result which is less than 5m3 of air per hour per m2 of floor area @ 50 Pascals expressed as < 5m3/hm2@50pa. Note that the volume of the building is based on the total volume within the building envelope as opposed to the sum of the volume of all internal rooms as is used for the Passivhaus standard.
[edit] Related articles on Designing Buildings
- Accredited construction details ACDs.
- Air change rates.
- Air permeability testing.
- Air pressure n50 test.
- Air tightness in buildings
- Airtightness of energy efficient buildings.
- Draughts in buildings.
- Energy audit.
- Floor plenum airtightness.
- Indoor air quality.
- Indoor air velocity.
- Passivhaus.
- Site inspections.
- Thermographic survey.
- The history of non-domestic air tightness testing.
Featured articles and news
Twas the site before Christmas...
A rhyme for the industry and a thankyou to our supporters.
Plumbing and heating systems in schools
New apprentice pay rates coming into effect in the new year
Addressing the impact of recent national minimum wage changes.
EBSSA support for the new industry competence structure
The Engineering and Building Services Skills Authority, in working group 2.
Notes from BSRIA Sustainable Futures briefing
From carbon down to the all important customer: Redefining Retrofit for Net Zero Living.
Principal Designer: A New Opportunity for Architects
ACA launches a Principal Designer Register for architects.
A new government plan for housing and nature recovery
Exploring a new housing and infrastructure nature recovery framework.
Leveraging technology to enhance prospects for students
A case study on the significance of the Autodesk Revit certification.
Fundamental Review of Building Regulations Guidance
Announced during commons debate on the Grenfell Inquiry Phase 2 report.
CIAT responds to the updated National Planning Policy Framework
With key changes in the revised NPPF outlined.
Councils and communities highlighted for delivery of common-sense housing in planning overhaul
As government follows up with mandatory housing targets.
CIOB photographic competition final images revealed
Art of Building produces stunning images for another year.
HSE prosecutes company for putting workers at risk
Roofing company fined and its director sentenced.
Strategic restructure to transform industry competence
EBSSA becomes part of a new industry competence structure.
Major overhaul of planning committees proposed by government
Planning decisions set to be fast-tracked to tackle the housing crisis.
Industry Competence Steering Group restructure
ICSG transitions to the Industry Competence Committee (ICC) under the Building Safety Regulator (BSR).
Principal Contractor Competency Certification Scheme
CIOB PCCCS competence framework for Principal Contractors.
The CIAT Principal Designer register
Issues explained via a series of FAQs.