Hi all, just wanted to share an observation I made this week. I installed a HEPA filter in my Leicester office which required me to take ambient particle count measurements for a few weeks, to make sure the filter works. I found that the ambient (unfiltered) particle counts in the 0.5 micron range increase 10-fold when the sun goes down. I do not see an increase in my local PM2.5 forecast on the BBC. I wonder if the BBC sampling stations are in the countryside with not many wood-burning houses nearby. In Leicester, I can now smell wood burning every night. I wonder if this is some of us trying to save on gas (admittedly, very costly) and choosing to make themselves sick instead (in the long run) by burning wood to stay warm. At any rate, I wear a mask whenever I smell smoke, so I will be OK.
Particulate pollution at night, wood ... - Asthma Community ...
Particulate pollution at night, wood burning
interesting! I hate this time of year anyway with so many bonfires, the smoke affects my breathing very badly and people seem to spread their firework parties out over a whole month now
I hate to tell people what to do, but when one's fun/pleasure make others sick, something needs to be done (like it was done with smoking indoors). But legislation moves slowly. Probably it will move faster when we get more wildfires due to climate change (e.g. in California, fireworks are illegal). In the meantime, I always have my mask and my inhaler at hand.
Update: the IQAir PM2.5 data appear to be more trustworthy.
"PM2.5 concentration in Leicester is currently 3.4 times the WHO annual air quality guideline value"
iqair.com/uk/england/leicester
that’s not good is it - it’s 2 x in central London
The fact that the govt services cannot even measure the air pollution reliably is concerning. My particle counter, as of 9 pm on Nov 5, 2022, reads 30 times the daytime levels, there is smoke, the explosions go off non-stop, and the IQair site now reports PM2.5 as "unhealthy for sensitive groups". While the govt report shows that it's all good. Incredible.
iqair.com/uk/england/leicester
uk-air.defra.gov.uk/forecas...
I’ve bookmarked that site as it’s a new one to me. I’ve always gone by defra in the past! Thanks for that 😊 I always have a mask on me too, and an inhaler in my pocket
Hi, I am interested in whether you find having a HEPA filter makes a measurable difference to your breathing. Thanks
CallysMom -- I apologize for the long text below
yes, a HEPA can make a huge difference, but only if it's a proper setup that allows ducting dirty air in and/or clean air out, and if you do your own testing of the efficiency. Most Allergy companies sell filters that are questionable in the HEPA standard, and these consumer filters cannot be ducted. When I was new to HEPAs 15 years ago (living through CA fires) my first "HEPA" filter (by "Austin air") was non-ductable, and it was only 50% efficient when I tested it, while the company claimed 99.93%. The company still exists and sells their filters, so, clearly most users never test their filters (and rely of the placebo effect, probably).
If one's budget is limited (under 1K), one can hope to only control the air in a small space, this needs to be engineered to work. No fluffy mattresses, carpets, etc in that space. I control the air in my bedroom and in my office at work (where I spend 80% of my life, sigh). For that, I place the Hepa box intake in an adjacent room or hallway ("buffer room") and duct the clean filtered air through a 200mm hole in the door to the room being controlled. This creates positive pressure in the target room, and also ensures supply of fresh air (I crack the window in the "buffer room" slightly). My office has an HVAC air supply (they implemented it after COVID), so that is easier to engineer with (I direct the incoming air into a 200mm duct and direct that into my HEPA, the hepa then blows the clean air into my face at my desk).
The only commonly available HEPAs that can be ducted in input and output are by IQAir. There are professional units, too (search "ducted hepa filter"), but they cost several K. IQair is relatively "cheap" at <1K. The issue with IQAiris that their HEPA membranes have an odor, so, if you are sensitive to odors, you would have to filter its output through an additional charcoal filter. Charcoal filters are available at horticulture (i.e. pot-growers' :)), suppliers; I use Dutch Touch filters.
Another issue with HEPA is the supply chain. There were major issues a year ago. So I found a Turkish supplier who sells their HEPA membranes to the nuclear industry, ordered 1 filter for £100, tested it, then ordered 10 more just in case. I am set for 10 years for now.
Particle counters are used to test if your setup works, and to debug if it does not. W/o a particle counter (or an access to one, e.g. from a colleague), I would not even bother. These counters used to be very costly (I have a 3K and a 6K unit), "Recently" (10 years ago) Dylos monitors became available ($300 is a bargain), and Amazon now sells numerous particle counters from China for even less. I do not have any experience with the latter, but I do own a Dylos, it has worked flawlessly for 10 years. This is the unit I took the measurements in my original post -- it sits on my office desk at all times.
dylosproducts.com/ornodcpro...
I posted a few of my HEPA setups on this forum; if you are curious, they should be searchable here
Every time I open the window to gulp in some fresh air all I get lately is a lungful of smoke- asthma no likely! So many round here have opted for log burners re energy costs but at others expense - of their health and well-being . Not to mention them bleating on about climate change whilst adding to pollution. We all have to breathe the same air so it should not be made toxic to us or the planet.
I live near the sea! Why can’t they use tidal power to fuel homes etc.?? It’s clean,free,carbon neutral,endless,can be timed to the minute twice a day every day regardless of weather.I am exasperated at how short sighted the governments are,especially here- we’re a bloody island with an unlimited supply of free and endless natural energy- use it!
But they would rather spend billions building more eye sores,taking up valuable farmland that is need for food production for the ever increasing population, nuclear with all its vulnerabilities like war targets (look at Ukraine) leaks,accidents,spent fuel rods that they ‘Hope’ will not leak from their concrete graves,killing everything and polluting the earth forever.
Off my soap box now. But please- think of how you affect others and the planet before you light that fire! Thank you,I’m here all week…..🤪
I don’t get why wave power hasn’t been further researched. It’d be expensive to install but would quickly get cheaper, and has enormous global potential. So why aren’t we investing in this technology 🤔 ? Carbon capture too - not popular with the Just Stop Oil purists but an interim solution which would give us time.
I avoid reading too much about this as it makes me angry and frustrated
Likewise! So frustrating. They can do it as has been proven in Nederlands,now Scotland ,in small areas but still most effective. We can’t tame the whole ocean but can use bits of it .I would definitely rather see a barge on the sea than hideous windmills, which no one can dare estimate the cost to birds and sea life,still use huge amount of lectrickery to run,inefficient,expensive and dependent on weather! Probably coz they don’t wanna know- money you know!
Finally getting their heads round peat extraction though heating climate changes that dynamic. The irony! So slow to adapt- isn’t that why species become extinct? That and man’s poisonous regime I guess.No,I’m not a hippie just a realist. And I’d like to breathe fresh air please! 😱
Tidal power technology is still in its infancy, AFAIK, and requires huge investments. Investors prefer to invest into Tweeter :). Maybe the ... tide!... will shift when 90% of people have severed asthma, not 10%
>>>Just Stop Oil purists
I liked that they made sure to spray paintings that had glass on them. Works for me
Carbon capture is even harder than tidal power, IMHO. The CO2 released in the last 150 years is already spread around the earth atmosphere, and will take 1000 years to get absorbed by the oceans (I am quoting the number by memory, may be off 10-fold :)). For a faster effect, scrubbing the CO2 from the entire atmosphere will prob require an air blower the size of the Himalayan range. I think everyday things can make more difference, and educate the population. Like restoring forests, replacing "parks" (those giant lawns that are used 1 day a year to play football) with trees, insulating homes etc will have more immediate and rewarding effects.
Vandalism is negative and stupid, makes more people anti their antics. We already know the score. There are better ways of educating people, eg the ‘woke’ generation - stop leaving tons of un recyclable rubbish at festivals and bbq etc. on the beach to be washed into the ocean while ‘saving the planet’.Hypocrites all.
Just stop oil is like saying just stop breathing; the whole world runs on it will do until a viable alternative is sourced, a pipe dream filled with something other than oil. Ideals are all very well if you can afford them. Planting trees is all very well but when the Amazon is being torched at the rate of knots,we could never grow them fast enough. Stop destruction at the source,dramatic feeble gestures futile.
Yes,the little things do make a difference- if everyone does them ,like stop burning things!! It’s not just asthmatics that suffer but so many are now affected by poor air quality eg smoke! Whole countries are having to close down for a day or more due to smog but start up the chimneys again the next day.🤷♀️
Anyhoo,stop burning things is my mantra! Have a fresh day tomorrow.😷
There is a "hourly historic data" link available on the IQAir web site. It's too bad it only goes back 48 hrs. If anyone knows a link to a dataset which goes back longer, please share!
The spike in the PM2.5 around 9-10 pm is very obvious. The good news is that by 3 am people are asleep in their cuddly beds, and do not have to heat the whole house/flat with burnt wood to stay cozy. I suppose, putting on a sweater is not an option, better make the neighborhood choke
Defra has information on air quality, but you need quite a bit of time to trawl through the various options to find what data you want and where for.
uk-air.defra.gov.uk/data/da...
DEFRA data on PM2.5 showed "low levels of pollution" for the same time points as the IQAir site showed "hazardous for sensitive groups".
Not surprising I guess as people will be travelling home from work plus as the air cools particulates held in warmer air are more likely to gravitate downwards. Woodburners which don't have filters are a real nuisance. If you need to go out I suggest wearing a warm scarf over nose and mouth - or a mask. There are some available for cyclists which filter out pollutants. Hepa filters are fairly good especially for pollens, dustmites, moulds etc. but there are more expensive models which filter out a range of chemicals as well.
was wondering , reading this if the sun shines into your office. The only reason I ask this is that I thought that if the sun heats up the room maybe the fine particles rise to the ceiling when it is warm and then fall when the room cools down. However, I know where I live that people are in more in the evenings and put their log burners on more then. I live in a small countryside town where many of the holiday lets have log burners. Even on a hot Summer evening people seem to put them on, maybe for the novelty value. I live entirely in the roof of an old church so it gets very warm indeed and yet I can't open the windows on warm Summer evenings because, being high up the stench from the log burners is intolerable 
.
I haven't noticed increases on particle counts when the sun goes up and shines straight into the office. I do wipe the linoleum floor once a week. I am thinking to add another filter that circulates the air inside (with a strong blower), since my own body is a key source of dust particles.
Not what you're looking for?
You may also like...
Discrepancy between DEFRA data and perceived pollution due to wood burning
What causes strange burning feeling if not asthma
burning sensation in lungs post asthma flair?
Asthma attack in woodland - could it be leaf mould?
Lifestyle changes / activities that help Asthma
Asthma related coughing fits through the night
Air Purifier - Helpful?
DofE expedition with asthma 
