PAS 2035 - Checking for Air Leakage Points

PAS 2035 is the new specification document that covers the 'whole-house' or 'whole building' retrofitting of domestic buildings and includes identifying key air leakage locations.

Checking air leakage paths using Leak Checker under PAS 2035

Under Section 8.5: Assessment of the PAS 2035 retrofit standard, an airtightness test may be required to test the air permeability of the building envelope, using an approved method, including identification of key leakage locations.

It is only mandatory for Path C risk levels, however, PAS 2035 additionally states that testing of the air permeability of the building envelope may be useful irrespective of the assessed level of risk, and should be carried out at the discretion of the Retrofit Coordinator.

Air leaks can occur anywhere but are most commonly found around windows openings, door frames, loft ceiling hatches, the top of basement walls, chimneys, wiring holes, recessed lights and plumbing vents. But just how can you identify the exact location of any such key leakage locations as per the PAS 2035 specification?

Find PAS 2035 air leakage points using Leak Checker

The Leak Checker diagnostics fan aims to complement our low-pressure Pulse air permeability measurement system by helping users to locate and address key or unwanted air leakage paths.

The kit consists of a highly portable fan that is hook mounted onto an extendable rod. This bar is then telescopically fixed across any window opening. The opening around the fan mounting and the window are then sealed up using the sheet and clamps provided in the kit.

The fan is then connected to an electricity supply via a standard 3 pin plug and to any mobile device from which it can be controlled via an App.

When switched on the fan provides an airflow of up to 2042m³/h which creates a pressure difference (either negative or positive) within the room. This pressure difference is great enough to enable air leakage paths to be very easily felt with your hand or visualised with a basic smoke pen or thermal imaging camera.

The fan itself measures just 295x300x81mm and the whole kit weighs less than 4kg making it highly portable. The operation is incredibly simple and the mounting rod easily extends to fit virtually any standard sized window.

It’s not intended as a measurement instrument in its own right but, instead is designed to complement any airtightness test by identifying the key leakage points as stipulated under PAS 2035 Section 8.5.1. This makes it an ideal piece of kit to keep in your PAS 2035 compliance armoury.


Richard England

Richard England

Head of Digital

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Leak Checker Diagnostics Fan

Leak Checker Diagnostics Fan

A portable diagnostics fan that can help identify air leakage paths within buildings, helping to minimise infiltration, improve airtightness and reduce remedial work required to pass compliance testing.

Learn more about Leak Checker Diagnostics Fan