Go Back  PPRuNe Forums > PPRuNe Worldwide > Australia, New Zealand & the Pacific
Reload this Page >

Well that should take care of the HEPA filter myth

Wikiposts
Search
Australia, New Zealand & the Pacific Airline and RPT Rumours & News in Australia, enZed and the Pacific

Well that should take care of the HEPA filter myth

Thread Tools
 
Search this Thread
 
Old 30th Sep 2020, 10:49
  #1 (permalink)  
Thread Starter
 
Join Date: Dec 2000
Location: Australia
Posts: 941
Received 26 Likes on 10 Posts
Well that should take care of the HEPA filter myth

https://www.abc.net.au/news/2020-09-...virus/12718748

My thoughts are it probably is a hostile environment for Covid...but it has to get there first. Trying to con people into thinking HEPA filters made an aircraft cabin safer always was a dodgy call.
ozbiggles is offline  
Old 30th Sep 2020, 11:01
  #2 (permalink)  
 
Join Date: Feb 2000
Location: 500 miles from Chaikhosi, Yogistan
Posts: 4,295
Received 139 Likes on 63 Posts
HEPA filters won’t stop COVID going from person to adjacent person. No one has ever seriouslyclaimed that.
What they do stop is COVID recirculating throughout the cabin.

One thing that Airbus’s cabin airflow studies recommend - and I have yet to see on 4 airlines I have paxed on in the last few months (including QF) - is closing the overhead air vents prior to pax boarding. Open they will both 1. Spread particles further and 2. Suck any particles into the airflow down onto the pax.
compressor stall is offline  
Old 30th Sep 2020, 11:04
  #3 (permalink)  
Thread Starter
 
Join Date: Dec 2000
Location: Australia
Posts: 941
Received 26 Likes on 10 Posts
Didn't they?

https://www.abc.net.au/radio/program...puted/12366380

They were very careful in their wording, trying to create an impression that didn't tell the whole story
ozbiggles is offline  
Old 30th Sep 2020, 12:04
  #4 (permalink)  
 
Join Date: Jul 2014
Location: England
Posts: 400
Received 1 Like on 1 Post
Originally Posted by compressor stall
One thing that Airbus’s cabin airflow studies recommend - and I have yet to see on 4 airlines I have paxed on in the last few months (including QF) - is closing the overhead air vents prior to pax boarding.
My experience as SLF in Europe pre-Covid (I haven't flown since March) was that all overhead air vents were routinely closed before boarding, presumably by the cleaners. I noticed that because I always wanted them open! YMMV wherever you are.
OldLurker is offline  
Old 30th Sep 2020, 12:24
  #5 (permalink)  
 
Join Date: Feb 2000
Location: 500 miles from Chaikhosi, Yogistan
Posts: 4,295
Received 139 Likes on 63 Posts

They were very careful in their wording, trying to create an impression that didn't tell the whole story
yes. Careful words.

However a plane will be safer than a bus or train for the same cabin volume per person. Those forms of mass transit (modern ones not red rattlers!) don’t have the same rate of clean HEPA filtered air coming in.

Last edited by compressor stall; 30th Sep 2020 at 23:22.
compressor stall is offline  
Old 30th Sep 2020, 12:36
  #6 (permalink)  
 
Join Date: Jul 2008
Location: Australia
Posts: 1,253
Received 195 Likes on 90 Posts
11 people infected with a pax load of 243. If the aircraft environment was conducive to the spread of the virus I would have expected a higher number. I would suggest that the 11 infected possibly got it by being seated close to the infected people plus face masks were not being worn by all pax at that stage.
Lookleft is offline  
Old 30th Sep 2020, 18:54
  #7 (permalink)  
 
Join Date: Aug 2004
Location: moon
Posts: 3,564
Received 89 Likes on 32 Posts
Lookleft, I haven’t kept up with what the airflow models are inside the cabin these days, all I seem to remember is that bleed air cost money, smokers were at the rear and the state of the cabin outflow valves at overhaul was just disgusting. Is it possible that the covid infected cruise passengers were sitting in a spot where there was not much recirculation? Maybe if they were in 1A and B they might have infected a plane load?
Sunfish is offline  
Old 30th Sep 2020, 21:36
  #8 (permalink)  
 
Join Date: May 2005
Location: QLD - where drivers are yet to realise that the left lane goes to their destination too.
Posts: 3,337
Received 182 Likes on 75 Posts
Trying to con people into thinking HEPA filters made an aircraft cabin safer always was a dodgy call.
Yet no cabin crew contracted COVID? Do they not breathe the same air? Do they not move throughout the cabin, thus being much more exposed to multiple zones?
Perhaps the HEPA filters were doing more than you think. I would say the infections were more likely caused by contact transmission, given the number of cruise ship passengers on board, and the small number of non-cruise passengers infected.
Traffic_Is_Er_Was is offline  
Old 30th Sep 2020, 22:46
  #9 (permalink)  
 
Join Date: Feb 2000
Location: 500 miles from Chaikhosi, Yogistan
Posts: 4,295
Received 139 Likes on 63 Posts
Sunfish, your first sentence is correct. The rest is highly improbable and not borne out by any evidence - papers or anecdotal - to date.
compressor stall is offline  
Old 30th Sep 2020, 23:43
  #10 (permalink)  
 
Join Date: Oct 2017
Location: Tent
Posts: 916
Received 19 Likes on 12 Posts
Originally Posted by Traffic_Is_Er_Was
Yet no cabin crew contracted COVID? Do they not breathe the same air? Do they not move throughout the cabin, thus being much more exposed to multiple zones?
Perhaps the HEPA filters were doing more than you think. I would say the infections were more likely caused by contact transmission, given the number of cruise ship passengers on board, and the small number of non-cruise passengers infected.
But cabin crew have contracted COVID 19 on at least 1 other flight.

Most cruise ships had pretty low numbers of COVID 19 on a % & time basis - 2 or 3 notable exceptions.
Bend alot is offline  
Old 30th Sep 2020, 23:54
  #11 (permalink)  
 
Join Date: Oct 1999
Location: ex EGNM, now NZRO
Posts: 551
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by Traffic_Is_Er_Was
Yet no cabin crew contracted COVID? Do they not breathe the same air? Do they not move throughout the cabin, thus being much more exposed to multiple zones?
Perhaps the HEPA filters were doing more than you think. I would say the infections were more likely caused by contact transmission, given the number of cruise ship passengers on board, and the small number of non-cruise passengers infected.
Routine practice in hospitals is for rooms to have a positive pressure; the clean air comes from the top, the dirty air sucked out at the bottom. I am guessing that is why CC are less likely to be infected, as they will routinely be above the faces of pax.
Anti Skid On is offline  
Old 1st Oct 2020, 03:01
  #12 (permalink)  
 
Join Date: Mar 2012
Location: Dark Side of the Moon
Posts: 1,433
Received 207 Likes on 69 Posts
I thought this was good news, you take a bunch of highly infectious symptomatic passengers and put them on a 5 hour flight with 200 plus other people with NO precautions and only 11 other people pick up the virus, they may have picked it up at the airport in the departure lounge, during boarding or disembarking etc, what it shows is that aircraft are not the incubators in the sky many claimed and with extra cleaning, hand washing, lack of service and mask wearing they probably are extremely low risk environments. That long haul study showed after an 8 hour flight a highly infectious person only infected those sat directly around him, once again this was before precautions were being taken.
Ollie Onion is online now  
Old 1st Oct 2020, 04:26
  #13 (permalink)  
 
Join Date: Feb 2004
Location: Aus
Age: 42
Posts: 381
Received 4 Likes on 3 Posts
Originally Posted by Ollie Onion
I thought this was good news, you take a bunch of highly infectious symptomatic passengers and put them on a 5 hour flight with 200 plus other people with NO precautions and only 11 other people pick up the virus, they may have picked it up at the airport in the departure lounge, during boarding or disembarking etc, what it shows is that aircraft are not the incubators in the sky many claimed and with extra cleaning, hand washing, lack of service and mask wearing they probably are extremely low risk environments. That long haul study showed after an 8 hour flight a highly infectious person only infected those sat directly around him, once again this was before precautions were being taken.
Precisely what I was thinking. 11 highly infectious pax got on, infected another 11. That could have happened anywhere inside the terminal at both ends rather than the aircraft itself. How does this compare to clusters that appear from pubs/clubs/restaurants? Very favourably I'd imagine. Another thing that get overlooked is that the air is a mix of 50% fresh and 50% re-circulated on an aircraft which equates to all the air being replaced every 2-3 minutes on a narrowbody. How fresh is the air at a gym or while seated indoor at a cafe/restaurant?

Make your own conclusions, those who choose to live in fear will never live.
turbantime is online now  
Old 3rd Oct 2020, 08:54
  #14 (permalink)  
 
Join Date: Oct 2020
Location: England
Posts: 26
Likes: 0
Received 10 Likes on 1 Post
With the increase look at HEPA filters it would be good for the regulators to mandate and regulate their use as opposed to just manufacturer recommended guidelines.
TLoraine is offline  

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.