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Orla Hegarty Profile picture
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17 Jun, 7 tweets, 3 min read
#Covid19 “Flying is safe”? ✈️
CO2 measurement on flight between Bilbao & Barcelona

.. recommended CO2 is below 800ppm... at 3,000ppm you’re breathing too much of other people’s exhaled air & at risk of inhaling the virus & becoming infected
USA flight (again highest risks of poor ventilation seem at boarding/disembarkation & taxiing)
CO2 monitors do not measure filtration of air, so don’t show that HEPA filters reduce risk ~when air is being circulated through filters~

IATA say modern aircraft have 50% fresh air /50% filtered air

Risk varies by aircraft, operation & maintenance..& number of people on board
another reading
& from Australia
scientific advice
Physics tells us that air ~does not~ move in straight lines (aerodynamics is the study of the motion of air).. airflow will also be affected by open doors, people moving around, passengers adjusting their own overhead airflow, etc
iata.org/en/youandiata/…

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More from @Orla_Hegarty

Orla Hegarty Profile picture
12 Jun
Why SupplySupplySupply won’t solve the #housing affordability problem

#1 ‘we are doomed to failure if we see it purely as a game of numbers.. lowering the bar to get developers to build tiny, dim, carbon-intensive, socially-isolating, unaffordable boxes’ alastairparvin.medium.com/if-the-uk-buil…
Why SupplySupplySupply won’t solve the #housing affordability problem

#2 most claiming that supply will meet demand (at a hypothetical equilibrium) expect it to take until 2025... which suggests 4 more years of rising house prices
extra.ie/2021/05/04/fea…
Why SupplySupplySupply won’t solve the #housing affordability problem

#3 Speculative developers now have high sales prices baked-in to financing.. if market prices drop they may lose funding, they can’t build & sell at a loss

*this from current apartment proposal in Dublin 7
Read 11 tweets
Orla Hegarty Profile picture
11 Jun
‘the space coloured red represents pure air under the most favourable circumstances of strong wind.. the blue indicates impure atmosphere’ (1854)

..#crossventilation keeps the air moving, so that stale air & viral particles are diluted & removed
Upper: ‘the state of the atmosphere in a non-ventilated church, the windows & doors being closed & lamps lighted’

Lower: ‘the tower or spire is made to act as well for the introduction of fresh air as for removal of impure air, & for both purposes it affords superior facilities’
‘a sectional view of one of the largest & most modern of ‘Ward Schools’ in New York which will convey some idea of the child-packing followed in some of them.. originally intended for 1,000 into which 1,400 are suffered to be crammed without an attempt at systemic ventilation...
Read 4 tweets
Orla Hegarty Profile picture
1 May
[Thread] Solving the #housing crisis means facing facts

#1 Planning Permission is not a barrier to housing in Dublin, there are over 40,000 ‘ready-to-go’ permissions for houses & apartments in Dublin Q2 2020

Just 2,000 homes were built in 2019, about 5% of available permissions
#2 Increasing supply alone won’t make housing affordable

‘additional 1% housing stock expected to lower house prices by 1.5% to 2%, all else equal’ -Economist @ianmulheirn

So by supply alone, Dublin would need 150,000+ new homes to become affordable housingevidence.ac.uk/wp-content/upl…
Housing is an asset, the value of that asset can rise & fall in the market. The amount of housing supply is a small part of pricing

Economist @DrCameronMurray calls this asset pricing ‘not supply mountain’
Read 17 tweets
Orla Hegarty Profile picture
29 Apr
‘1 in 1,000 cases traced to outdoor transmission’ has now been reported around the world as research from Ireland

To correct record: this isn’t a research study & isn’t valid

Here’s why... 1/
npr.org/sections/healt…
basis of ‘1 in 1,000’ is 262 cases in 42 outbreaks
*only from outbreaks where >2 infected, & not all cases
*only from places that ~may~ be outdoors (21 construction, 20 sport & 1 in community)

& this 262 is compared to ~total~ 232,164 cases recorded in Ireland (to 24 Mar 21) 2/
Meanwhile this ~research~ has flown around the world, & risks influencing people’s behaviour & public policy 3/ ImageImageImageImage
Read 4 tweets
Orla Hegarty Profile picture
24 Apr
[Thread] 🇮🇳 #India Prevention

#Covid19 is mostly caught by breathing infected air, not from hands

😷 Wear well-fitting masks everywhere indoors

🍽 Eat & drink outside & at a distance

🪟💨 ventilate rooms/vehicles, keep airflow moving at all times, open doors & windows 1/
🌀turn off or limit use of air-con units that recirculate cool, dry air

💦 avoid low humidity in air-con rooms (showers & cooking add moisture)

🛏 avoid shared bedrooms, partly open windows & doors for night airflow

🚙 🚌 open windows, turn fans to full fresh air & mask 2/
Why is air-conditioning higher risk for #Covid19?

🥶 virus survives longer in cool, dry air
🐪 nose mucus dries out & people are less protected
💨 less fresh air is brought in (to save energy)
📦 rooms/cars are sealed, & so virus is trapped & builds up like invisible smoke 3/
Read 10 tweets
Orla Hegarty Profile picture
10 Apr
Yet again, #Covid19 in #construction misreported @TheBusinessRTE

35 construction outbreaks in last 4 months (while sector mostly closed) of which 18 are currently ongoing & 4 are new construction outbreaks w/e 3 April

Let’s be open about the risks so that we can eliminate them
As with many other sectors, #Covid19 ‘risk’ to construction companies & employers ≠ #COVID19 risk to Ireland from that sector

When sectoral employers say they are “safe” they mean within their specific legal H&S obligations as employers, & this is small part of the full picture
employer H&S responsibilities stop at the gate & generally only extend to their own employees.. not sub-contractors, service providers, ‘bogus’ self employed etc.. or to transport, commuting, shopping, lodgings & other risks to a community that arise from activity in that sector
Read 5 tweets

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