coronavirus guidance webinar · webinar programme wednesday 6 th may – change to programme •...
TRANSCRIPT
Coronavirus Guidance Webinar5th May, 2020
Agenda
• Poll
• CBI Update
• Poll Result
• Ventilation & air conditioning: prevention of recirculation and optimisation of air movement
• Q&A
POLL
What is your experience of opportunities to tender at present?
• Tenders are significantly reduced• Tenders are somewhat reduced• There is no real change from pre COVID-19• Tenders are somewhat increased• Tenders are significantly increased
Ventilation & Air Conditioning:
Avoiding the risk of COVID19 propagation
Graeme FoxHead of REFCOM
Recent reports: does AC spread COVID19?
• Recent press reports
• Recirculation of Air Conditioning: what does it mean?
• Types of Air Conditioning
• CDC publication from April 2nd
• CDC follow up investigation April 16th
• Conclusions
Press reports
BESA response & guidance
• BESA responded initially on 11th March with TB048 “COVID19 & Air Conditioning Systems”
• Quickly adapted guidance as new evidence emerged
• TB048 Version 4 was published on 8th April• In line with industry consensus: REHVA &
ASHRAE guidance included
• Addresses inflammatory language used by mainstream media
• Later versions include practical measures for contractors to observe
Types of air conditioning
The term air conditioning broadly covers cooling & heating; humidification/dehumidification; air movement, ventilation; and filtration/air cleaning…
It can be a large rooftop mounted AHU with or without cooling or heating coils, chillers (including heat pumps) feeding wet system fan coil units, large multi-split heat pumps (including VRF/VRV), or single split heat pump direct expansion (DX) fan coils
Guangdong restaurant reports
Initial report included a basic sketch that suggested there were 5 tables in the restaurant, and that an extract fan was situated in the far wall opposite an AC high wall unit.
It concluded that “droplet transmission was prompted by air-conditioned ventilation”, although they did also admit their study was limited and that no modelling simulation was carried out an the air pattern within the zone.
Guangdong restaurant reports
The 5 tables in the original sketch were in fact at one end of a larger zone;
The AC unit was one of 5 in the restaurant;
The extract fans were switched off, as were the fresh air supply fans on the day in question;
No other patrons were infected from other tables;
None of the waiting or kitchen staff became infected;
The only fresh air supply was via infiltration with the limited negative pressure only being created by the toilet
extract fans at the far end of the restaurant!
Guangdong restaurant reports
A stagnant recirculating zone at one end of the restaurant was created.
The lack of air movement and, crucially, dilution of infected air allowed the exhaled droplets of infected particles to be
transmitted over a further range than the normal expected short-range transmission.
This concurs with previous studies of the WHO and others in previous pandemic outbreaks of airborne viruses.
The study concluded that over crowding and poor ventilation increases risks of transmission:
which concurs with the guidance already issued by ASHRAE, REHVA and The BESA
Maximise fresh air volumes to dilute any contaminated air.
Panel Q&A
Graeme Fox Head of REFCOM, IOR Board, ACRIB Director
Pete TutaloHVAC & Gas Technical LeadRoyal Mail Property & Facilities
Peter Rogers Ventilation Consultant, Author DW144 & DW172
Webinar Programme
Wednesday 6th May – Change to programme • H&S Site Guidance notes plus • Gokhan Hassan, MD of GHCS
Thursday 7th May • Dame Judith Hackitt
BESA Training - Lockdown Learning
Thursday 7th MayDr Chris Owen, Manager, Customer Technical Services at Tata Steel Tubes.
Reducing risk when specifying building and industrial services pipework.
Sign up on www.theBESA.com/COVID19
State of Trade Survey
SUPPORT FROM BESA
www.thebesa.com/covid19• Access lots of guidance• Latest news• Slides and recording available on the website• Daily webinar – forward programme and signup• Facebook page for furloughed workers • New Lockdown learning
[email protected]• Email to send queries to• If you want to join the WhatsApp group email us your mobile
