Study finds transmission of aerosol particles in cruise HVAC system 'undetectable'

[LACruiser88]

Another positive sign for cruising to resume...

 

https://www.seatrade-cruise.com/environmental-health/study-finds-transmission-aerosol-particles-cruise-hvac-system-undetectable

[chengkp75]

As I said last March, when everyone was screaming for modifications to cruise ship HVAC systems.  Nothing new here, well known in the HVAC industry.  Not going to change anything as far as restarting cruises, as the CDC recognized this fact back then as well, and did not require any changes to HVAC systems, or even cleaning of HVAC systems, on ships that had outbreaks.

[Astro Flyer]

This is the current Princess statement on their website...would you know if anything is new?

 

“We’re maximizing fresh air and enhancing air filtration by upgrading our ships’ HVAC systems to MERV 13 filters that remove a large portion of airborne particles, following the highest CDC guidance. Air is replaced throughout public spaces and staterooms every five to six minutes. Plus, we’re adding HEPA filtration systems to key areas such as medical centers and isolation rooms”.

Edited February 28, 2021 by Astro Flyer

[chengkp75]

31 minutes ago, Astro Flyer said:

Air is replaced throughout public spaces and staterooms every five to six minutes.

This is a x10 air exchange, about what most systems will do, whether on ships or on land.  New filters, but whether there is any evidence of active viral load at the old filters, has not been shown, so whether the filters will actually do anything, for covid, is questionable, though it will likely upgrade overall air quality.  HEPA filters for medical center is new, but something that land hospitals have had for decades.  Not sure where they are locating "isolation rooms", or how they are separating the HVAC system for those cabins to provide the HEPA filtration, so don't know how effective it will be.

[Astro Flyer]

Thanks...greatly appreciate your insights Chief.

[Thrak]

If it filters the dang cigarette smoke out of the air it will be nice. Not only does it ooze out of the casino but every time someone opens the door to Churchill's a huge cloud of stink surges out.

[West Coast Gal]

Air exchange seems to be the most important factor.  I saw a study that had an air exchange on a commercial aircraft from the floor to the ceiling every 2 min while in a house because we have sealed up our homes so well is every 6 hours.  And I agree with a great side note of getting rid of the cigarette smoke would be lovely.

[chengkp75]

11 minutes ago, West Coast Gal said:

Air exchange seems to be the most important factor.  I saw a study that had an air exchange on a commercial aircraft from the floor to the ceiling every 2 min while in a house because we have sealed up our homes so well is every 6 hours.  And I agree with a great side note of getting rid of the cigarette smoke would be lovely.

Yes, air exchange is a major factor.  This gets the contaminated air out of the space quicker, the more air exchanges there are.  What many folks were/are concerned about is the recirculation of the air, but as this study shows, the virus is not detectable at a viable level (sufficient quantity and in "living" condition) after having traveled through the return ducting, air handler and supply ducting of several hundred feet in many cases.

[vakamalua]

Always look to see who paid for the study...

[GonzoWCS]

Interesting read and discussion.  Thanks for the link.

 

Cheers

[chengkp75]

13 minutes ago, vakamalua said:

Always look to see who paid for the study...

ASHRAE studies have shown the same thing, which is why there is no outcry for revamping or upgrading any land based central HVAC system, which would include virtually every high rise and commercial/industrial building in the world.