Installation of extract fans for extracting stale air out of properties is a basic requirement as per the Building Regulations 2010 Approved Document F. Adequacy of extractor fans installed in a property as per the Approved Building Regulations ensures healthy indoor environment. Adequate ventilation by extract fans not only provides suitable indoor environment by extracting stale air but also prevents moulds growth and condensation from coming back. Hence saves occupants from deteriorating their health.
Adequacy of extract fan ventilation is important and can only be verified through proper air flow testing. Post installation flow rate testing of mechanical extract fans is now a requirement of Approved Document F. Relevant building control bodies require proof of adequate extract fans with minimum flow rates. Properties that have undergone major retrofitting works for improvement in energy efficiency by installing energy efficiency measures are required to undertake extract fans air flow rate testing by a qualified and certified domestic ventilation assessor.
Testing air flow rate of extract fans involves updated knowledge and relevant expertise. Air flow rate testing of installed extract fans can be undertaken by any of the following methods.
Unconditional Method: A power flow hood is used in this method of extract fan air flow rate testing which involves elimination of back pressure without putting any additional restrictions on existing fans under testing. Correct performance of extract fans is then verified in light of results obtained on equipment.
Conditional Method: Variety of equipment for testing extract fan flow rates is usually used in this method. Conversion factor is used for adjusting reading that is provided by manufacturer and is usually based on testing by a UKAS accredited body. Record sheets requiring information related to fan make, its model, test equipment, required output, adjusted output and conversion factor is provided as part of testing.
Minimum Benchmark Method: Minimum benchmark method is widely used method for conducting extract fans air flow rate testing. Vane anemometer is fitted with a hood which is placed over extract fans that are to be tested. Flow rates of extract fans is then measured and compared with benchmark values mentioned in Approved Document F of the Building Regulations 2010. If values of extract fans exceeds the benchmark then it is considered reasonable and is acceptable for Building Control Bodies.
Minimum Flow Rates Required – Approved Document F
Fans installed in a property become less efficient and compromise extraction over time. Installation of extract fans in existing properties does not necessarily mean that it complies with the requirements of Building Regulations Approved Document F. Proper testing of extract fans is conducted in order to verify adequacy of extract fans to fulfil requirements of the Building Control Bodies. Extract fans installed in domestic properties must meet following minimum flow rates.
Room | Minimum flow rate |
Kitchen (adjacent to hob) | 30 l/s |
Kitchen (elsewhere) | 60 l/s |
Utility room | 30 l/s |
Bathroom | 15 l/s |
Sanitary accommodation | 6 l/s |
Required ventilation rates are usually measured in litres per second (l/s). Vane anemometer fitted with a hood is placed over extract fan of which air flow rate to be measured. Vane anemometer displays real-time output that subject extract fan is extracting. At start reading kept on changing and then stabilises. Readings once stabilise is then considered final and recorded for issuing a pass or fail status.
We the KCS Electrics strongly believe in professionalism, quality and commitment. Our client’s satisfaction and loyalty make us dominate in Extract Fans Air Flow Rate Testing services. KCS Electrics outstanding record, effective responsiveness, efficient scheduling, prompt attendance and swift delivery helps our clients in getting their domestic ventilation requirements fulfilled as per the Building Regulations 2010 Approved Document F without any inconvenience. Our prices are market competitive so as our responsiveness which makes us standout in the ventilation industry.
KCS Electrics qualified, accredited and experienced air flow rate assessors offer exceptional extract fan air flow rate testing services at your doorstep. We ensure that our domestic ventilation assessors keep themselves updated with requirements The Building Regulations 2010 Approved Document F guidelines.
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