Issue:

On 31st October 2023, one of our ATSPACE engineers visited a site in Prescot, Merseyside, to conduct a ventilation test on two plots that had extract fans installed in the bathrooms and kitchens. The test involved measuring the airflow rates of the fans using a calibrated anemometer and comparing them with the design specifications. However, the testing results showed that both plots failed to meet the required flow rates for the fans, which were 15 litres per second (l/s) for the bathroom fans and 30 l/s for the kitchen fans. The actual flow rates measured were only 10 l/s and 20 l/s respectively.

Solution:

The ATSPACE engineer suspected that there was a problem with the ducting behind the fans, which could affect the performance of the ventilation system. He used his extensive knowledge of what can affect the flow rates of a ventilation fan and inspected the ducting carefully.

He found that there were several issues with the ducting, such as:

• The ducting was too long and had too many bends, which increased the resistance and reduced the airflow.
• The ducting was not properly sealed at the joints, which caused air leakage and pressure loss.
• The ducting was not insulated, which could lead to condensation and mould growth.
The ATSPACE engineer explained the situation to Keith, who was the client onsite, and suggested some possible solutions to rectify the issues. They agreed to work together to fix the ducting by:
• Shortening and straightening the ducting as much as possible, while ensuring that it met the minimum length requirement of 300 mm from the fan outlet.
• Sealing all the joints with mastic or tape to prevent air leakage.
• Insulating the ducting with suitable material to prevent condensation and heat loss.

Result:

After fixing the ducting, the ATSPACE engineer retested both plots and found that they both fully complied with Part F of the building regulations. The flow rates of the fans increased to 16 l/s for the bathroom fans and 32 l/s for the kitchen fans, which exceeded the design specifications. The client was very satisfied with the outcome and thanked the ATSPACE engineer for his professionalism and expertise. The ATSPACE engineer completed his report and submitted it to the client along with his certificate of compliance.