**Building Regulations Part F Changes are coming to England. Are you ready?**

Brookvent has a full range of ventilation products that can help you meet these new requirements of the building regulations changes. Firstly, let us look at what Part F is and how the changes affect your compliance for future builds.

https://staging.brookvent.co.uk/heat-recovery-ventilation-systems/ https://staging.brookvent.co.uk/continuous-extract/ https://staging.brookvent.co.uk/introduction/

What is Part F of the building regulations?

Part F of the building regulations 2010 provides guidance on building ventilation, including building air quality and preventing condensation in domestic or non-domestic buildings.

Changes to Part F of the building regulations are coming into effect in June 2022. In recent years the move towards improvements to the thermal performance and air tightness has positively improved the thermal comfort and energy consumption of buildings.

Therefore, these improvements can increase the amount of internal air pollutants within a home:

To negate the effect these pollutants have on indoor air quality it is essential that the correct amount of ventilation is provides.

Summary of current Part F

Part F defines four methods of ventilation

Background ventilators & intermittent extract fan
Passive stack ventilation
Continuous mechanical extract
Continuous mechanical supply and extract with heat recovery

Summary of the key changes

Part F will reduce the ventilation strategy to a combination of:

Extract ventilation from wet rooms, be either intermittent or continuously running systems
Whole dwelling ventilation to provide fresh air to dilute pollutants, either mechanically, or via background ventilators
Purge ventilation to remove high concentrations of pollutants and water vapor

This is an effort to simplify the regs and make them easier to design and implement.

Requirement to calculate total equivalent ventilator area on a room-by-room basis
PIV (Positive Input Ventilation) is not passed, unless it it has been BCB certified, with a BBA Certificate.
Buildings which achieve an air tightness score of 3 or less, are considered highly airtight and will require a continuously running mechanical extract system.

Equivalent area ventilators new matrix

Intermittent Extract Flow Rates (System 1)

Continuous Extract Flow Rates (System 3/4)

Dwelling Ventilation Targets (System 4)

https://www.ashbyenergy.co.uk/changes-to-building-regulations-part-f-2021-in-summary

Important Notes on Installation and Testing

Intermittent extracts require only a single reading to gain compliance.
Continuous extracts require two readings.
Mechanical Ventilation with Heat Recovery requires a full set of building calculations plus the testing and commissioning of the installed system.
Only 1.5m of flexible duct is allowed in any duct run from an axial fan, 3m for centrifugal.
Accessible location for testing, and maintenance.
Insulated ducting in lofts.
For intermittent and continuous extract systems to comply you need to be installing background ventilators.
It is not permissible by building regulations to mix intermittent with continuous or MVHR ventilation systems in a single dwelling.

The Testing Process

Notes are made on the number of extracts in the dwelling
A hooded vain anemometer with appropriate hood is placed over the extract
Record the flow rate of the extract in Litres Per Second
Inspect the duct.
A record of the the duct condition
Lastly, issue the certificates

The Reality of Part F

Firstly, a Legal Requirement since 2010
Approximately 70% of buildings fail the extract rate requirements!!!!!!!
It has been difficult to have testing completed at install stage
Extract rates for kitchen hoods nearly always comply if straight through walls
Commonly utility areas sized incorrectly.

Reasons why extracts fail:

Incorrect sizing of extract fan
Poor installation
Long lengths of flexible ducting

If you have any questions or queries in regards to complying with the new requirements for Part F, Please contact us on 02890616505 or at; hello@brookvent.co.uk

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