Air Flow / Maintenance of Ventilation Systems at Heathrow
Request ID: FOI-2630-2223 Date published: 13 February 2023
1. The cleaning plan/schedule for the ventilation system at Heathrow Terminals 123 and Terminal 4
2. How many times the system has been cleaned and the dates.
3. The air quality readings from 2015 to present
4. How often the filters are cleaned/changed and the dates.
5. How many stations on the underground have not had their ventilations cleaned for over 6 months
TfL Ref: FOI-2630-2223
Thank you for your request which we received on 18 January 2023.
Your request has been considered in accordance with the requirements of the Environmental Information Regulations and our information access policy. I can confirm that we hold some of the information you require. You asked:
The cleaning plan/schedule for the ventilation system at Heathrow Terminals 123 and Terminal 4
Ventilation assets have been maintained as per SFG20 guidelines (standard for building maintenance specifications), with planned preventative maintenance (PPM) - which includes the cleaning of key components - occurring every six months. We have recently revised the intervention frequency to three monthly PPM regime for the pre panel / bag filters. The pre panel /bag filters ensure that the ventilation provided is “filtered” ensuring it’s clean from external contaminates. We have also undertaken Supply Ventilation ductwork cleaning - the ductwork carries the fresh air to the occupants’ offices / space and we are monitoring these systems.
How many times the system has been cleaned and the dates.
While we are unclear which system you are referring to here, cleaning frequency is as per the SFG20 intervention described above.