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Ventilation Testing

SAP Calculations - EPC's - Air Permeability Testing - Water Calculations - Ventilation Testing

Ventilation Testing

As specialists not generalists we only deal with Parts L,F and G of the building regulations.We can advise on suitable products and equally importantly on installation protocols.

(without an air permeability test)

£25 per unit

  • *Plus an attendance fee
  • *Plus a milage fee

Testing Guidence

Testing of fixed fans should be carried out at the terminal point within the room served by the fan. Where the ventilation to a kitchen is provided via a cooker hood it may not be possible to carry out the test at the terminal point in the kitchen. In this case it may be reasonable to carry out the test on the outside of the dwelling. If the kitchen extract point is above ground floor level, it would be reasonable for the BCB to take a view on compliance depending on the performance of the remaining fans in the dwelling.

There are three suitable testing methods for testing fans as described in Approved Documet Part F. We test using one of the methods listed below.Both testing methods utilise a vane anemometer fitted with a hood.

METHOD 2(Conditional Method)

Once the fan is tested, the reading is adjusted using a conversion factor specific to the fan make and model and the type of equipment being used. The conversion factors must be provided by the fan manufacturer and be based on third party testing by a UKAS accredited body.

METHOD 3(Minimum Benchmark Method)

Minimum benchmark levels have been set which factor the impact of the test equipment. If a fan performance exceeds the minimum benchmark value it would be reasonable for BCB to assume that the fan is performing to the required level and accept the test results as showing compliance with Part F of the Building Regulations.

Types of Ventilation (Systems 1 to 4)


Intermittent extract fans

This is the most common system and is found in most new dwellings – Extractor fans are fitted in kitchens utility rooms, toilets and bathrooms and trickle ventilators are fitted on the windows.


Passive Stack Ventilation

Unusual in this country for various reasons. In terms of building control compliance, only a visual inspection of the design and installation is needed.


Mechanical Extract Ventilation (MEV)

Typically these are systems that continually extract air from wet rooms (kitchen, WC, bathroom, utility). When these rooms are in use, the system will increase the volume of air extraction.


Mechanical Ventilation Heat Recovery (MVHR

These systems extract stale air from all rooms within a dwelling but unlike an MEV system, stale air is passed through a heat exchanger, the recycled heat is then reintroduced into the dwelling.

Minimum Extractor Rates


Hood extractors, 30l/s. Other Intemittent extractors 60l/s. Continuous extraction (MEV/MVHR) 13l/s


Intermittent extractor 30l/s Continuous extraction (MEV/MVHR) 13l/s


Intermittent extracton 6l/s Continuous extraction (MEV/MVHR) 13l/s


Intermittent extractor 15l/s. Continuous extraction (MEV/MVHR) 13l/s


OFFICE: 01392 683664          MOBILE: 077968 46047        EMAIL: info@pecairsap.com


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Tips For Success

Manufacturers’ published extract rates are compiled using optimum laboratory conditions. Unfortunately real life installations return very different results.

The primary reason a fan does not achieve the extraction rate specified by the manufactureer can usually be attributed to ducting. To improve your chance of success consider the following:-
Ducting Design

Keep the length of ducting to a minimum.
Where possible use rigid or semi regid ducting.
Avoid verticle lengths of ducting.
If you do use flexible ducting, avoid kinks and pull the ducting tight before cutting.
Keep ducting bends to a minimum, where possible use 45° rather than 90° bends.
Source good quality, high flow rate fans.

The Legislation

Approved Document Part F of the Building Regulations requires builders to provide evidence of the testing of all fixed fans to their Building Control Body within 5 days of the test being carried out.

The Guide

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.