Air Tightness Testing for Air and Smoke Control

Air pressure testing to understand air leakage, air changes and/or air paths.

Understanding air permeability and/or air changes has a wider application than energy efficiency, for example in ensuring certain types of ventilation perform their functions as required or for tracing the path of air/smoke/smells.

Testing for air and smoke control


To meet the requirements of HTM-03 for isolation suites, operating theatres, etc in relation to infection control.

As part of recent changes to Health Technical Memorandum (HTM)-03, isolation suites, operating theatres, pharmacy septic preparation, containment and similar facilities are required to be air tightness tested to BTS 3/2018.

The whole suite is tested to confirm air tightness limits movement of air and allows the pressurisation system to work efficiently, individual rooms within the suite are tested in varying configurations to measure air permeability and understand specific leakage rates through doors and transfer grilles.

The recommended air tightness is 2.5 m3.h-1.m-2@50Pa

To confirm that builders shafts are sufficiently air test for smoke ventilation systems to operate effectively.

Air testing is conducted on shafts that have been created in a stair/lift core to ensure they are sufficiently air tight to allow Mechanical Automatic Opening Ventilation to extract smoke from escape/access routes in the event of a fire.

The testing is to ATTMA Technical Standards or CIBSE TM23 based on a target of less than 3.8 m3.h-1.m-2@50Pa

To confirm that plenums formed by raised access floors are sufficiently air tight for ventilation air supply rates to be achieved.

Air tightness testing is carried out on Raised Access Flooring and the Plenum created below to BG 65/2016 to confirm that they are sufficiently airtight for the ventilation system to operate as required.

Testing is conducted on the Raised Access Floor and Plenums separately with recommended targets of <1.5 l/s/m2 of floor area at 50Pa and <0.7 l/s/m2 of floor area at 50Pa respectively.

To identify the route by which a smell is passing from one property to another.

Pressure testing can be used to trace the path of smells/smoke between flats, houses or units. Air or smoke can be moved under negative or positive pressure to show the likely path by which smells are travelling between properties.

Room integrity testing is the testing of enclosures that are protected by a gaseous fire suppression system. In the event of a fire, these systems release a gaseous agent designed to put out the fire without damaging any equipment/documents. These fire suppression systems are commonly used in document/equipment archives and data/server rooms.


The main standards in the UK for room integrity testing are BS EN 15004 & ISO 14520. It is advised that the enclosures are tested at the installation/commissioning stage and then annually/whenever changes are made in the enclosure thereafter, to ensure and maintain fire safety. Not regularly testing an enclosure protected by a gas suppression system could risk the fire safety of the enclosure, as well as the building the enclosure is in. This may also invalidate your building insurance.  

Our Air Testing Process

Our air test engineers are home-based and well-placed to cover Greater London and the City, Kent, Essex, Surrey, Sussex, Hampshire, Berkshire, Buckinghamshire, Oxfordshire, Hertfordshire, Bedfordshire and Cambridgeshire, we are able to test all over the UK.

Our process is as follows:

1. Answer any queries

We are happy to talk through what is involved, what to watch out for and when to test. We can provide guidance and checklists.

2. Price & Date

We provide an indicative price based on the size of the building and location, ahead of issuing a formal quote based on PDF drawings. We can look at pencilling in dates to suit your programme, our lead times are typically 1-2 weeks but we can often fit in single tests at shorter notice.

3. Preparation

We confirm a date. Our engineer will call you ahead of the test date to talk you through the preparation and process plus agree the timings. We would also look to confirm the air permeability that has been targeted.

4. On the day of testing

We conduct the test. Testing is done through a pressure test whereby fans are installed into a doorway of the building and used to create a measurable difference between the pressure inside and outside of the building. The amount of air needed to maintain this difference can be used to indicate the volume of air escaping through the fabric (what would be draughts in the building’s day-to-day life).

A negative pressure difference can be used to detect air flows from inside or a positive pressure difference can be used to push smoke through leakage paths to highlight them.

5. Paperwork

We issue certificates for each test within 24hrs of the test but we can issue them on the same day (when requested).

What our clients say about us

“ALT were extremely helpful and knowledgeable. They worked with the site team to identify and resolve issues during construction.”
“I have used Air Leakage Testing Ltd on two separate occasions at my property and found them to be extremely thorough and professional at all times. The turnaround between site visit and subsequent reports was quick and efficient - making my life a whole lot easier! Would highly recommend to anyone!”

Established in 2002



Helpful Engineers

We work with you to achieve the best result, identifying potential issues and repeating the testing once these have been addressed. We are on hand to answer any questions before, during and after the testing.

Flexible & Responsive

We try to fit in with the dates and times you need the test, we try to work around other trades to minimise disruption on site. We issue quotes and certificates within 1 working day, our lead-times are typically around a week but we will try and fit you in sooner if required.


We have been air testing since 2002 and all our test engineers have a vast amount of experience.

Great value

Our prices are very competitive but we can also undertake air and sound testing on the same visit to save you more money. If you do manage to find the testing cheaper, we will beat any quote.

Get a quote

Complete a few details about your project and we will provide an estimated cost. Provide more information and we will issue a formal quotation.