When should ventilation testing be booked?

The system should be installed, powered, accessible, clean and set up for commissioning before final airflow readings are taken.

Does ventilation testing replace the installer commissioning work?

No. The installer remains responsible for the installed system and its setup. The required evidence and responsibilities should be agreed for the project before testing.

Part F · measured airflow

Ventilation Testing Across England

Airflow measurement for extract fans, MEV and MVHR systems, helping builders, installers and property teams assemble clear ventilation evidence.

Request a quote Call 0161 710 5778

Why measure airflow?

Confirm that installed ventilation is delivering the intended flow

Good ventilation depends on the installed system, the fan settings, ductwork, terminals and the route air takes through the property. Testing provides measured values that can be compared with the project design and applicable requirements.

Extract fans

Measure airflow at kitchen, bathroom, utility and WC terminals where intermittent or continuous extract is installed.

MEV systems

Check continuous extract terminals and system settings across the dwelling, subject to the installed design and access.

MVHR systems

Record supply and extract airflow at accessible terminals so system balancing and commissioning evidence can be reviewed.

Testing route

From system details to measured results

Review the design

Confirm the ventilation type, intended flow rates, dwelling information and evidence needed.

Make it ready

The system should be installed, powered, accessible, clean and set to the correct operating mode.

Measure terminals

Suitable airflow equipment is used at the relevant supply or extract terminals.

Record evidence

Results are set out clearly so the installer and project team can complete their records.

Before the visit

Ventilation testing preparation

Incomplete installation and blocked access are common causes of delays. Before the appointment:

Make sure fans, control switches and central units have permanent power.
Fit grilles, valves, terminals and external vents in their final positions.
Clean construction dust from filters, terminals and accessible ductwork.
Set background ventilators and internal doors as required by the agreed procedure.
Provide the ventilation design, target flow rates and installer commissioning information.
Leave access to loft-mounted or cupboard-mounted equipment where inspection is required.

Airflow readings do not correct an installation fault on their own. The installer may need to adjust controls, terminals or ductwork before final evidence is complete.

Common questions

Ventilation testing FAQs

Which ventilation systems can be measured?

The scope can include intermittent extract fans, continuous mechanical extract ventilation and mechanical ventilation with heat recovery, subject to the design, access and evidence required.

When should testing be booked?

Book once the system is installed, powered, accessible and ready for commissioning. Allow time before handover in case the installer needs to make adjustments.

Do I need the design flow rates?

Yes, where available. The intended rates and ventilation strategy help the tester understand what the installed system is meant to achieve.

Does testing replace installer commissioning?

No. The installer remains responsible for the system and its setup. Agree the required records and responsibilities before the visit.

Can air tightness and ventilation testing be booked together?

Often, yes, if both systems and the building envelope are ready. Send the project programme so the most practical order can be discussed.

Related services

Complete the wider project evidence

Ready to check the airflow?

Send the property address, system type and target completion date.

Request a project quote