Our paper led by @HenryBurridge on modelling the combined IAQ, infection risk and thermal aspects of nat vent school classrooms with and without HEPA filters is published
A short 🧵 on what we did 1/sciencedirect.com/science/articl… We assume a well mixed space and use a box model together with indoor and outdoor temperatures and assumptions about the building fabric and heating to model the thermal environment and air quality over time. We also model virus 2/

Today it’s #CleanAirDay so here’s a reminder that your indoor air is as important (if not more so) than outdoor air. We spend up to 90% of time indoors so most air pollution exposure happens inside buildings. But there’s lots you can do to reduce this 🧵 1/ We’re exposed to lots of pollutants without realising it. It’s easy to think of traffic fumes and smoke, but we’re exposed to loads of chemicals in our daily lives including personal care, cleaning, furnishing and cooking. We’re even exposed to microplastics in air 2/

On the face of it both boxes of Fairy Snow from @ProcterGamble look pretty much the same. Both XXL and do 65 washes.

But let’s look a little closer 1/ Turns out the pack weight is quite different, with the new box 325g lighter. 2/

A little bit of the history of Victorian school ventilation from a visit to Beamish museum 1/ The classroom has windows on both sides for light and cross ventilation. Those onto the corridor open into upwards pointing hoppers, with the same the opposite side of the corridor. Safe and avoiding low level drafts 2/

Fabulous session today to wrap up research from theme 2 of the @PROTECT_NCS programme. So much research into measuring and modelling transmission and mitigation from a huge number of talented people. Lots still in write up, but here’s a sample of what’s already published 🧵 1/ Work led by @H_S_E and @dstlmod developed a CFD model of exhaled microbes and validated against human data from @UKHSA experiments. This helps understand how different size aerosols deposit and remain airborne, and how they evaporate onlinelibrary.wiley.com/doi/full/10.11… 2/

New paper from the @PROTECT_NCS study measuring the performance of five air cleaners in a small room scale chamber. Study shows some interesting complexities - a little 🧵 1/
liebertpub.com/doi/full/10.10… The study was in an unventilated room and tested devices using a bacteriophage, MS2. The MS2 was aerosolised in the room and decay measured over time with and without a device present. The authors also used an OPC at the same time to measure particles. 2/

We’ve put together a video from the @PROTECT_NCS project as a reminder of factors that increase risk and measures to mitigate covid and other respiratory diseases in workplaces, backed up by some of the research from the programme 1/

https://twitter.com/protect_ncs/status/1604771019583111169

Some measures remain easy - though surfaces probably pose a low risk, washing your hands and keeping things clean is just good basic hygiene. It’s still a good idea to think about reducing occupancy and using hybrid interactions to reduce numbers of people exposed 2/

The video from the @theNASEM workshop on respiratory transmission on transport is now available. Check out session 1 for an overview of our @epsrc TRACK research by Susan Grant Muller from @ITSLeeds 1/ nationalacademies.org/event/11-16-20… Our TRACK project has been running for around 2 years and has developed understanding around transmission and mitigation to support policy makers and operators. You can find out an overview and the team at track-project.org.uk 2/

Some thoughts on extremes of humidity. A couple of weeks ago we were stuck in rain and fog, and everything felt damp. Now it’s crisp and chilly with some very cold temperatures. Anyone got dry, itchy skin at the moment? A little🧵on humidity and temperature - and a few tips 1/ In designing ventilation, air con and heating systems in buildings, we have to think about these relationships all the time. It’s called psychrometrics (with an r) and is all about how temperatures, humidity and energy in air are related. 2/

Our new paper on modelling respiratory aerosols from the @PROTECT_NCS project with @dstlmod and @H_S_E is out onlinelibrary.wiley.com/doi/10.1111/in…. A short🧵 on the key findings 1/ We carried out CFD modelling to look at the fate of different sizes of aerosols emitted from a person coughing in a mechanically ventilated room. We consider how evaporation of aerosols affects the virus carried 2/

How quickly do microorganisms deposit from air? How does ventilation affect surface contamination? We looked at this in a new study led by @waseemhiwar 1/

https://twitter.com/waseemhiwar/status/1593885316360081411

The study used a controlled 32m3 chamber with nebulised staph aureus bacteria - the aerosols were typically 2-3 micron diameter. We looked at air concentrations and surface deposition at different ventilation rates 2/

The more I think about this winter, the more I worry that damp and mould are going to become big problems in far more housing and create a long lasting health problem. 1/ A small amount of damp or little bits of mould around a window seal or shower tray can usually be easily remedied. But if lack of heating creates more damp and leads to mould to become widespread it’s much harder to tackle 2/

If you’re heating your house less watch out for signs of damp. Colder surfaces are more likely to have condensation and buildings with lower insulation levels or issues with thermal bridging may show damp more readily with less heat. 1/ Solving damp quickly is not always easy but there’s some things you can do. Look out for and fix any obvious leaks indoors in water/waste pipes or outdoors in guttering that runs down the wall and creates a moisture source 2/

I know it’s going colder, but covid is on the way up again and pretty fast so please don’t abandon ventilation. It’s still important if you’re mixing indoors. There’s a few things you can do to improve indoor air without a massive energy bill 1/ First think about when and where you need to ventilate. It’s always good to have some fresh air, but it’s most important when you’re with other people outside your household. 2/

If your school, work, library, community centre is naturally ventilated, seriously consider investing in air cleaners for this autumn and winter. Even with higher elec prices they’re likely to be cheaper to run than opening windows and also trying to heat the place. 1/ With higher energy prices occupancy of many office and social spaces may be higher with people wanting warmth without spending money at home. At the same time many of these places will also be trying to reduce heating costs by keeping windows closed 2/

With extreme heat forecast next week its going to be hard to stay cool. There's no easy answer, but here's a few thoughts about what you can do in your home, school or office to try to keep the building a bit more comfort 1/ Before going into buildings there's some basics - drink plenty of water, wear light clothing, stay out of the peak of the sun, limit exercise, watch out for vulnerable people and if you are feeling unwell seek health advice - there's more info here gov.uk/government/new… 2/

Lots of infections around at the moment so here’s a reminder of the steps to manage risk in schools, workplaces and social settings as we get towards the peak of another wave. Not everything works everywhere, but lots of this can be applied with a bit of thought 1/ 1. Manage the source. The most effective way of reducing risk is to not have someone infected present. This isn’t easy as many people are infectious before symptoms, but there’s things you can do to reduce the chance 2/

Ventilation is one of the best approaches we have for reducing respiratory disease and it’s time to pay attention again as cases of COVID are so high. Here’s some Saturday morning thoughts on what to do now and in the future 1/ In the summer the most obvious way to get good ventilation is to spend time outdoors - transmission risk is not zero but it is much reduced by the significant dilution from outdoor air 2/

Goodbye Kuopio,goodbye #IndoorAir2022. Thank you @isiaq and all the organisers for a wonderful conference with great venues, great science, great food and lots of conversations 1/ After 2 years of working under enormous pressure, this week has been the biggest mental reset I’ve had in a very long time. Being able to share experiences and have time to reflect on the future research has been amazing 2/

Our buildings matter for health and it’s time for a major upgrade to be resilient to disease including future pandemics. Today we announce a new report from @RAEngNews and @CIBSE on what is needed and why. A 🧵 on what we did: 1/ The new report raeng.org.uk/news/news-rele… takes a systems look at infection resilience in buildings to consider across design stages and operations on how we can make them healthy alongside being safe and sustainable. 2/

Our paper on far UV (222nm) with @EwanEadie @waseemhiwar @FletchLou, @DJBrennerCRR was finally published this week. A little 🧵 on what we did 1/nature.com/articles/s4159… Firstly what is 222nm UVC? It’s a germicidal wavelength of UV light that can inactivate microbes in air or on surfaces. Tests show it is much safer for human exposure than conventional UVC at 254 nm. That means it may be possible to apply it in a room more easily 2/