Bangkok Air Pollution

[xylophone]

On ‎6‎/‎10‎/‎2018 at 4:46 AM, balo said:

When it's really bad , I can also smell it

I can smell it too and the air doesn't have to be that bad either, so on the one hand I'm happy that the air pollution isn't bad, but on the other get fed up with the constant smell!

[phycokiller]

On 4/6/2018 at 6:27 PM, mommysboy said:

Good posting.  It seems like Pattaya is fairly polluted too, which surprises me as it is coastal.  Building dust is lethal imo.  Great work!

its coastal, but during the dry season the wind comes down the chinese coast, pretty much from the big chinese cities, and overland from vietnam, and because its dry likely theres a lot more dust. in the wet season it comes off the indian ocean and just crosses a narrow part of thailand to get there so presumably its a lot cleaner. pretty much the same in bangkok too. heres a good site to see the winds. another thing to keep in mind is the Map Ta Phut Industrial Estate, altho I doubt the wind comes from that direction much https://www.windy.com/ . 

[DaveInSukhumvit]

On 4/8/2018 at 11:30 AM, SooKee said:

I binned the instructions that came with the 3M box that I bought but IIRC that only made reference to trimming the sheet to size, not undersize, could be wrong though.  But if it had looked in the diagram that they were trimming to 70% size I'm pretty sure I'd have noticed.  Since the post above mentioning covering only 70% of the filter was made I've searched and found quite a lot of videos and instructions recommending the same.  I'm currently trying the sheet trimmed to 70% and so far the performance is OK, no need to increase the fan or reduce temperature to achieve the desired cooling.  Will see how it goes.  Doubtless the sheet will be less effective than a full covering (can't see how it wouldn't be) but at full covering it's a non-starter for me. 

Probably works same as DIY filter.  Not every particle goes through the filter first time, but eventually, many circulate through and get caught in filter.

[DaveInSukhumvit]

On 4/13/2018 at 1:08 PM, TallGuyJohninBKK said:

The one other thing I do know for certain, because I tested it, is the Filtrete sheets alone DO help reduce PM2.5 in a room even in the absence of a purifier. So if anyone here is NOT running a purifier, they should at least be using Filtrete sheets instead, and changing them regularly.

It seems a great idea for traveling to bring Filtrete sheets.  For example, I was in Hanoi last week and the air was exceptionally bad.  I can't bring an air cleaning machine (DIY or Air Purifier).  But bringing a roll of paper, and paying a little more for electricity (not) could work.
 

Also, many thanks for TallGuy for your many contributions on this thread. I've read up to this point and John and others have been very helpful and informative.

 

On 4/13/2018 at 12:11 PM, xylophone said:

I have a theory on it and it goes like this – – the cooling fan is powered by a little induction motor and these little things can go on forever, and if there is an increased load on them, they can slow up and not suffer any ill effects, and of course because they are so small they don't really affect the power consumption. BUT what can happen is (I believe) because the airflow is diminished and so is the cooling effect, the Aircon has to work a lot harder for a lot longer to get down to the 23° that I want

I think you are exactly correct.  Thanks for posting Xy...

[TallGuyJohninBKK]

8 hours ago, DaveInSukhumvit said:

It seems a great idea for traveling to bring Filtrete sheets.  For example, I was in Hanoi last week and the air was exceptionally bad.  I can't bring an air cleaning machine (DIY or Air Purifier).  But bringing a roll of paper, and paying a little more for electricity (not) could work.

 

 

The 3M Filtrete sheets may be a more practical, and longer lasting alternate solution, than I had originally thought in prior posts here.

 

Because, at that time when my Filtrete sheets in the bedroom were getting clogged up in a week or more of routine bedroom use, I happened to have a habit back in that time of putting on shower powder in the adjoining bathroom, and then getting dressed in the bedroom every morning. And I didn't realize it at the time, but that minor powder every morning was playing havoc with my bedroom AC filters.

 

Once I stopped using the shower powder in the mornings, I found my bedroom AC filters weren't getting clogged up nearly as fast, and my Filtrete sheets likewise were lasting a whole lot longer -- consistent with what some other users here in the thread were reporting earlier.  And I couldn't figure out why mine weren't lasting nearly as long. But, now from trial and experiment, I know the powder was making the difference.

 

So, when the bad pollution season arrives toward the end of this calendar year, I'll probably go back to putting Filtrete sheets on my bedroom AC unit and then see how those perform with and without the bedroom HEPA air purifier. My experience last season was, the Filtrete sheets brought down the PM2.5 levels quite a bit all by themselves, and of course worked even better with the purifier added.

 

At least in BKK, the packages of Filtrete sheets are typically available at HomePro stores, but I've been buying mine also from the official 3M store on the Lazada site, where they often have two-for-one promotions and similar sales that bring their prices down below those of HomePro.

 

 

[DaveInSukhumvit]

Thanks for the update TallGuyJohn.

 

I'm a newbie on this forum with the simple goal to learn more and share information so others can benefit.  I make mistakes, so feel free to correct nicely when appropriate.

In reading the thread up through page 28, I saw several references to the charcoal pre-filter.  I think that is a misnomer - at least with the DIY solution.  Notice the direction of the arrows in the image below on the HomePro filter - and the charcoal on the outside (exhaust).  AFIK, arrows are the universal symbol for intended flow direction in air conditioning systems.

It doesn't really matter on this filter AFIK.  If you hold the charcoal up to the light (eg daytime window) you will notice that the charcoal areas are simply pockets that hold charcoal particles that move around.  You can see right through to the ribbed filter.

[TallGuyJohninBKK]

43 minutes ago, DaveInSukhumvit said:

In reading the thread up through page 28, I saw several references to the charcoal pre-filter.  I think that is a misnomer - at least with the DIY solution.  Notice the direction of the arrows in the image below on the HomePro filter - and the charcoal on the outside (exhaust).  AFIK, arrows are the universal symbol for intended flow direction in air conditioning systems.
 

 

From what I understand, charcoal pre-filters generally serve two purposes:

1. They help capture larger particles and prevent them from getting to your HEPA filter

2. They help capture odors/smells in the air, at least during their first 2-3 months of use.

 

Without a relatively cheap charcoal or other prefilter, the lifespan of one's relatively expensive HEPA filter is likely to be shortened. So in that respect, they're a good expenditure/investment and help maximize the life of one's expensive HEPA filter.

 

Generally, you want the charcoal or other prefilter to be on the air intake/inbound side of the HEPA filter.

[DaveInSukhumvit]

With all due respect - which you certainly earned - I think Hatari uses activated carbon after HEPA filter.  IMO the flow makes sense looking at it by particle size.  The bigger the particle, the earlier it is filtered.  The Hatari carbon chunks in the RAP-1201 filter are large when viewed by eye in light.  Carbon catches some of the ultra-small particles like smoke and gasses that pass by.

 

[TallGuyJohninBKK]

1 hour ago, DaveInSukhumvit said:

With all due respect - which you certainly earned - I think Hatari uses activated carbon after HEPA filter.  IMO the flow makes sense looking at it by particle size.  The bigger the particle, the earlier it is filtered.  The Hatari carbon chunks in the RAP-1201 filter are large when viewed by eye in light.  Carbon catches some of the ultra-small particles like smoke and gasses that pass by.

 

 

 

The example you're showing of the air purifier above appears to show several filters, including a pre-filter on the front side of the HEPA filter. So that pre-filter is performing the larger particle functions I mentioned above.

 

Most purifier units just have a HEPA filter and a carbon pre-filter, and usually it's on the front/incoming air side.

 

As I mentioned above, what you do NOT want to do is have the HEPA filter be the first filter to handle incoming raw room air. You want a prefilter of some kind, charcoal or otherwise, on the front end.

 

 

[balo]

What an amazing day here in Pattaya !   For the first time in a long time I get 0 on my SNDWAY, that's right , both inside my condo and outside on the balcony = 0 .   

I can't remember last time that happened.  

I did some exercise outside tonight , and the air was fresh and cool .  

 

 

 

 

 

[DaveInSukhumvit]

18 hours ago, TallGuyJohninBKK said:

As I mentioned above, what you do NOT want to do is have the HEPA filter be the first filter to handle incoming raw room air. You want a prefilter of some kind, charcoal or otherwise, on the front end.

Thanks John.  I appreciate your insistence on a prefilter.  I posted elsewhere about the proper orientation of RAP-1201 and nobody argued with me.  But I prefer the right answer over my own answer.  This may be the time to eat my words.  I also have a "Cannon" DIY purifier and it has a fiber-mesh pre-filter (and no charcoal).  I know some (most?) of the DIY people put charcoal first.

I'm not sure how to prove one flow orientation over another in a non-standard use environment.  Ideas are welcome.  Or, if you know more, please share.  If not, I will do what only an idiot would try.  I've only been running the filter for about a month so I will  reverse the filter.  Probably reverse outside for a few minutes, then leave the fan/filter running in a small room when I'm away for a few hours.  The thinking is that it will dislodge the bigger particles (outside), then recirculate the smaller particles into the filter.  AFIK, PM2.5 doesn't even wash out of a face mask, so small particles are unlikely dislodge from HEPA filter.

The measure of a good or dirty filter in a DIY fan should be revealed by an AQI meter with slower air cleaning.  Now I'm generally running 3-4 mcg AKA ug/m3.  When the filter is plugged, I expect higher numbers.  I ran the last filter backward ? for 3-4 months Feb-May w/o an AQI meter. This time, I should see a difference (in time). 

[TallGuyJohninBKK]

I'm not sure what you mean when you talk above about "reverse" the filter and running the filter backwards.

 

As your photo above illustrated, HEPA filters are meant for one directional air flow, being the direction typically listed on an arrow on the side or top of the filter. There's no reason to deviate from that.

 

Charcoal pre-filters, on the other hand AFAIK, have no directional element. But if someone has been using an existing charcoal filter with the air passing thru in a particular direction, I wouldn't go reversing that midstream.

 

However, in a case where the HEPA and charcoal or prefilters are separate pieces and not part of some integrated/packaged filter unit, there's no reason or need to be changing the direction of the air flow thru those filters, even if one wants to change the orientation to have the charcoal/prefilter come first instead of after the HEPA filter. Just swap the positioning of the two filters, with the airflow direction for both remaining the same.

 

If you're talking about some kind of single unit multi-filter package that combines various filters together, then obviously, I wouldn't be monkeying with that and I'd follow the air flow directional orientation as directed by the filter unit.

 

[DaveInSukhumvit]

6 hours ago, TallGuyJohninBKK said:

If you're talking about some kind of single unit multi-filter package that combines various filters together, then obviously, I wouldn't be monkeying with that and I'd follow the air flow directional orientation as directed by the filter unit.

My Hatari RAP-1201 is a "multi-filter" package.  One side is a standard HEPA pleated filter (below), on the other side is Charcoal filter.  The flow direction arrow goes from HEPA white to Charcoal black.  My blue fan photo above just shows the Charcoal side.

Of course I'm going to monkey with it.  It is DIY.  ? 

I looked closely at both sides, and they both have screens before the filter.  Screen before  charcoal filter on the exhaust side.  Screen before the pleated HEPA filter on the intake side.  Close enough for me.  I'm sticking with the flow direction shown on the blue fan photo above.

Dave

 

[DaveInSukhumvit]

I like AirVisual site.  But I don't understand how a hotspot develops in the middle of the Atlantic.

 

[DaveInSukhumvit]

All of a sudden air in BKK turned unhealthy.  Notice red spike on PM2.5 graph below.  Not sure the cause.  My guess is burning dirty Australian coal in nearby power plant with low ambient wind.  

 

[TallGuyJohninBKK]

Yep, that's a very odd, uncharacteristic spike for this time of year, which shouldn't be seeing those kinds of high levels.

 

But not sure what to make of it. When I woke up this morning, my unfiltered air reading in my living room in Central BKK was still 7 mcg, which would be much higher if the outside air were at the bad levels listed above.

 

Also, as of the 10 am reading, the Chula Hospital measuring site I follow was down to 93 AQI after being at 138 AQI or so as of 8 am.

 

[TallGuyJohninBKK]

For the last couple months, I haven't had to be paying close attention to the PM2.5 readings every day in BKK, because they've been consistently low and nothing to worry about, this having been the off-season for pollution.

 

But the last couple days in BKK that's changed, and I don't know if it means the return of an early air pollution season that doesn't normally come till November, or simply a temporary weather-related situation. At any rate, today, I was wondering why my air purifier was suddenly having a harder time keeping the PM2.5 levels inside my home down at a good levels.

 

So then I checked the outside readings for BKK, and found out why. And this is even after it had a pretty good rain earlier this morning. Not good!!!  Hope it's temporary and not back to the facemasks season already...

 

 

 

 

[SooKee]

Contemplating picking one of these up from Lazada (Xiaomi S2):

 

https://www.lazada.co.th/products/mi-air-purifier-2s-i229298588-s350712230.html?spm=a2o4m.searchlist.list.1.7ab52d64L71Ewm&search=1

 

I know @xylophone uses one, just wondering how they hold up filter wise and how often it needs changing.  Not sure as yet (yet to do some digging) if they only take Xiaomi brand replacements, sure seems to be a few of different types.  Figure it would be more efficient than the filtrate sheet (though I might use that as well at 50% coverage) provided the filters have some life.

[xylophone]

23 minutes ago, SooKee said:

Contemplating picking one of these up from Lazada (Xiaomi S2):

 

https://www.lazada.co.th/products/mi-air-purifier-2s-i229298588-s350712230.html?spm=a2o4m.searchlist.list.1.7ab52d64L71Ewm&search=1

 

I know @xylophone uses one, just wondering how they hold up filter wise and how often it needs changing.  Not sure as yet (yet to do some digging) if they only take Xiaomi brand replacements, sure seems to be a few of different types.  Figure it would be more efficient than the filtrate sheet (though I might use that as well at 50% coverage) provided the filters have some life.

Been very happy with mine SooKee and the filter looks like new...……….but perhaps I was being a bit paranoid in buying it as the reading/air quality in my room is permanently on 001!! 

 

I also have a Philips Vitashield IPS which has had good write-ups.

[SooKee]

1 hour ago, xylophone said:

Been very happy with mine SooKee and the filter looks like new...……….but perhaps I was being a bit paranoid in buying it as the reading/air quality in my room is permanently on 001!! 

 

I also have a Philips Vitashield IPS which has had good write-ups.

Cheers. Ordered from Lazada, seems a good price at 4,599.  Ordered the SNDWAY SW-825 as well at 1,400.  Having had experience of Ali Express buyer protection I only order small value items from official stores and where buyer protection, aside from delivery failure, won't be needed, same price as AE anyway, plus COD.

[JimShorts]

On 8/5/2018 at 10:18 AM, DaveInSukhumvit said:

I like AirVisual site.  But I don't understand how a hotspot develops in the middle of the Atlantic.

 

Most likely the pollution was carried from land into the ocean. 

 

The same thing happened in the Pacific in August. The smoke from the wildfires in Canada blew down the entire west coast, then blew out to sea. I watched it happening day by day. 

[Days Off]

On 8/5/2018 at 10:18 AM, DaveInSukhumvit said:

I like AirVisual site.  But I don't understand how a hotspot develops in the middle of the Atlantic.

 

Dust from the Sahara perhaps?  Very common for that area of the Atlantic.

[edwardandtubs]

I bought a Mi 2s air purifier but it seems there's no way of connecting my Xiaomi mobile phone to it without WiFi. Well, I don't have WiFi at home as I use 4G. Is this thing really so crap that there's no way for me to control it without a WiFi connection?

[edwardandtubs]

The Mi 2s is ok if you can get it at a discount. The power button is also the mode button and if you put it on high it stays on high. Don't need to connect it to a smartphone.

[SooKee]

Well up into the amber today ????

 

[edwardandtubs]

18 minutes ago, SooKee said:

Well up into the amber today ????

 

Most days will be between now and March.

[kekalot]

On 9/10/2018 at 5:03 PM, TallGuyJohninBKK said:

For the last couple months, I haven't had to be paying close attention to the PM2.5 readings every day in BKK, because they've been consistently low and nothing to worry about, this having been the off-season for pollution.

 

But the last couple days in BKK that's changed, and I don't know if it means the return of an early air pollution season that doesn't normally come till November, or simply a temporary weather-related situation. At any rate, today, I was wondering why my air purifier was suddenly having a harder time keeping the PM2.5 levels inside my home down at a good levels.

 

So then I checked the outside readings for BKK, and found out why. And this is even after it had a pretty good rain earlier this morning. Not good!!!  Hope it's temporary and not back to the facemasks season already...

 

 

 

 

my understanding of it (and it might be wrong) is that they are calculating it wrong here

 

it should be a number made out of PM2.5 AND PM10 together somehow (possibly not just added)

I am too lazy to look it up, but I know for a fact that this is how it USED to be calculated up north near chiang mai until one day the meter went from 200+ to about 40 because they took out the PM2.5 from the equation (opposite of what is happening here)

 

149 is exactly the PM2.5, PM10 is 68, if the numbers are to be added it's 217

[edwardandtubs]

18 minutes ago, kekalot said:

my understanding of it (and it might be wrong) is that they are calculating it wrong here

 

it should be a number made out of PM2.5 AND PM10 together somehow (possibly not just added)

I am too lazy to look it up, but I know for a fact that this is how it USED to be calculated up north near chiang mai until one day the meter went from 200+ to about 40 because they took out the PM2.5 from the equation (opposite of what is happening here)

 

149 is exactly the PM2.5, PM10 is 68, if the numbers are to be added it's 217

You are wrong. The overall AQI is whichever number is worst. 

[blackhorse]

Grunluft air purifier on lazada highly recommended with a built-in counter. If I put a drop of oil in the frying pan the counter goes From 5 to 300 and the unit kicks in to highest fan speef

3600 baht with 4 filters

[TallGuyJohninBKK]

11 minutes ago, edwardandtubs said:

You are wrong. The overall AQI is whichever number is worst. 

That's correct. And here in Thailand, whether BKK or CM, that worst/highest number is usually the PM2.5 value, which was VERY BAD (into the red unhealthy for all category) for a couple of afternoons/evenings recently in BKK.

 

And overall, the day to day PM2.5 values have been getting higher in BKK lately, signaling that the peak smog season from November to April (varying some year to year) is soon arriving. There's also some patches of red level PM2.5 readings for BKK forecast for the coming several days.