Air Tightness

Ventilation Testing

Regulation 42 of the Building Regulations 2010 requires builders to provide evidence of the testing of all fixed fans to the Building Control Body (BCB) within 5 days of the test being carried out. The Domestic Ventilation Compliance Guide (DVCG) published in 2010 gives the approved procedures for measuring air flows and reporting the results for Systems 1 to 4 described in Approved Document F 2010. However, following the procedure for testing System 1 axial fixed fans using a vane anemometer has presented practical challenges. In particular, it has been shown that the resistance of the testing equipment can adversely affect the test results, to the extent that a compliant fan may appear not to meet the recommended extract ventilation rates in Table 5.1a of Approved Document F. Builders have also found the description of the procedure to be unclear. NHBC have been working with industry and the Department of Communities and Local Government (DCLG) to devise a solution to these issues to allow accurate testing and reporting of fixed fans to be undertaken for all new dwellings.

Ventilation testing and ventilation commissioning are actually two different things. Testing refers to extractor fans, like you would find in a toilet, bathroom or kitchen. These are tested to see how much air they extract. Commissioning refers to more complicated ventilation systems, such as Mechanical Ventilation Heat Recovery (MVHR). These need to be balanced, to make sure the correct amount of air is either being extracted from or supplied to every room in the house.

The tests must be undertaken using UKAS calibrated equipment and should be conducted by an engineer registered with a competent scheme with respect to domestic ventilation technologies. All SK technicians have successfully completed the BPEC Domestic Ventilation course and all of our equipment is fully UKAS calibrated
Ventilation is incredibly important in all dwellings. A property without sufficient ventilation is far more likely to have problems with mould, condensation and damp. In addition to this, Pollutants in your home’s air can cause poor indoor air quality, which in turn may cause dizziness and headaches, plus aggravate allergies and asthma. With a sufficient ventilation system, you’re ensuring a good supply of fresh air and improving yours and your dwelling’s well-being.

Ventilation Types

There are 4 different types recognised in building regulations. Testing and/or commissioning has to be carried out on Types 1, 3 and 4:

Type 1

Intermittent extract fans with background ventilators – This is what is found in most houses – Extractor fans in kitchens, toilets and bathrooms and trickle ventilators on the windows.

Type 2

Passive Stack Ventilation – This is very rarely seen. It is a system which uses a combination of cross ventilation, buoyancy (warm air rising) and the venturi effect to ventilate. It is rarely used because it’s very much weather dependent.

Type 3

Mechanical Extract Ventilation (MEV) – This can either be a whole house system or a localise system for specific rooms. Multiple ducts will run from a constantly running unit to wet rooms (kitchen, WC, bathroom) continuously extracting stale air. When these rooms are in use, the system will boost up to extract a larger volume of air.

Type 4

Mechanical Ventilation Heat Recovery (MVHR) – This is similar to Type 3, except that it also supplies fresh air to all non-wet rooms (bedrooms, dining room, living room). The heat from the stale extracted air is kept in the central unit and used to heat the fresh air from outside before it is supplied to the house.

Air Tightness Testing in Scotland

Air Tightness

acoustic consultancy link image


aecb logo
bpec logo