Domestic Ventilation Testing/Comissioning

A Ventilation Test makes sure you correctly configure the ventilation systems in your building and that the air flow is of a good standard. This is in order to maintain a high standard of indoor air quality.

Furthermore, Ventilation Tests make sure designers follow The Building Regulations. This is so every component of the ventilation system – whether it’s a single fan or a full extraction system – complies with rules set out by the government.

Why Do I Need Ventilation Testing/Commissioning?

Part F (England & Wales) of The Building Regulations requires Ventilation Testing. This part of The Building Regulations is concerned with indoor air quality. Click here for PART F

By measuring the ventilation flow rates you can be assured of the very best air quality within your home, poor indoor air quality will affect both the occupants and building. By testing/commissioning your ventilation system is working effectively you can control the following which may contribute to a unhealthy environment/property damage -

Removal of stale air
Moisture levels, if not properly ventilated can lead to mould growth
Removal of pollutants/odours from cooking and washing
Removal of harmful VOCs contained within many household products
Proper ventilation can improve your cognitive function
Reduce the spread of airborne pathogens
Can help to maintain a balanced temperature (alongside other measures)
Manage the 'fresh air' entering a building which may contain pollen, dust etc (MVHR systems only)
Over ventilating will affect heating costs
Condensation forming on or within the building fabric
Maintain optimal healthy humidity levels between 40-60%

It is not unusual to find that a fan when fitted actually extracts the full amount claimed. All new build dwellings and some conversions will need ventilation testing/commissioning.

Types of ventilation we test/commission

SYSTEM 1 - Natural ventilation (intermittent extract fans with background/trickle ventilators). This is the most common with intermittent extract fans to all wet rooms and supply air being provided by trickle vents on windows.
SYSTEM 3 - MEV (Mechanical Extract Ventilation). MEV systems run continuously slowly removing air from all wet rooms with a boost function when cooking/washing, supply air is provided by trickle vents on windows. MEV systems are usually a single centrally located unit with duct runs to extract terminals.
SYSTEM 4 - MVHR (Mechanical Ventilation Heat Recovery). MVHR systems are similar to MEV extract, but the 'fresh air' is provided by continuous supply to all habitable rooms with the supply air being warmed by the extract air via a heat exchanger within the unit. MVHR systems are usually a single centrally located unit with duct runs to both supply and extract terminals.
DMEV (Decentralised Mechanical Extract Ventilation) - As system 3 without the need for duct runs, individual extract fans are used instead of one central unit.
DMVHR (Decentralised Mechanical Ventilation Heat Recovery) - As system 4 without the need for duct runs, The central MVHR unit and all ducting is replaced with individual supply/extract terminals.

Ventilation Testing Equipment, Automatic air volume flow meter

How Is Ventilation Testing/Commissioning Done?

Once the full details of your ventilation system and plans are received prior to attending site. We work out your ventilation requirements using 3D modelling if necessary. On site we will adjust/balance the supply/extract terminals on MVHR systems, adjust extract terminals on MEV systems and measure the flow rates of your ventilation system using a UKAS calibrated automatic air volume flow meter which is the only method to properly commission/balance MVHR systems, this allows us to accurately measure your chosen ventilation system as installed within the property, which then enables us to make sure your ventilation system complies with these requirements:

All kitchen intermittent extractor fans must extract at least 30 litres of air per second. If an intermittent extractor fan in the kitchen is not adjacent to a hob, it must extract at least 60L p/s. All continuous extraction units in the kitchen must extract at least 13L p/s.
For bathrooms, the extraction rate of an intermittent extraction unit must extract at least 15L p/s, or 8L p/s for continuous extraction units.
Intermittent extraction units in utility rooms must extract at least 30L p/s, or at least 8L p/s for continuous extraction units.
The dwelling must have an adequate overall ventilation standard rate. This will depend on the number of bedrooms. For example, in one bedroom properties the overall standard ventilation rate must be 19L p/s. However, in five bedroom properties this rate must be 43L p/s (or 0.3L p/s x useful floor area).

When Should Ventilation Testing/Commissioning Be Carried Out?

You should carry out Ventilation Testing/Commissioning once power is available and you have fully installed the ventilation systems. We recommend carrying out Ventilation Testing at the same time as your final Air Tightness Test. Combined tests are offered at discounted rates.

How long will Ventilation Testing/Commissioning take?

Once we have worked out your ventilation requirements off site, a typical MVHR unit should be around 2-3 hours to commission/balance, and a typical property with upto 5 intermittent extract fans should be completed in about 1 hour.

What do I get?

Once the Ventilation Testing/Commissioning is complete you will be provided with a certificate (within 24hrs of payment) showing the results. This certificate will be lodged with ATTMA which if compliant will also satisfy the conditions of the Building Regulations part F. Passiv/low energy properties will also receive 3D modelled drawings and calculations for their files.

Tips to help your ventilation system comply

At least 10mm undercuts to internal doors.
Check for restrictions at supply/exhaust grilles.
Keep intermittent fan duct runs as short as possible.
Make sure duct runs are straight - not kinked/sagging.
Check connections are tight between fan and duct.
Use the right fan and configure it correctly.
Make sure MVHR/MEV units are installed to allow for servicing.
Make sure MVHR/MEV duct runs are accessible for cleaning.
Use of semi rigid radial ducting for MVHR/MEV duct runs.