Bangkok Air Pollution

[TallGuyJohninBKK]

11 minutes ago, edwardandtubs said:

Bizarre mindset. "Low-end" price masks from 3M have been shown in fit tests to remove 97% of pm2.5 so on an extremely polluted day like today with pm2.5 at 100 you would be breathing in 3 micrograms per cubic metre - well within the healthy range. More expensive masks from other manufacturers have been shown to be inferior. And it keeps my face cooler and more comfortable than valved varieties. Your haughty mentality is getting in the way of you finding the best mask.

 

The most troubling thing of all this is, now a year later from the last smog season, it remains surprisingly difficult here to find legitimate N95 masks for sale here to the average consumer. Lots of retail stores don't stock them, or if they do, in limited stocks and often out of stock. And not much better from the various online sources....

 

That's probably ONE reason, among others, that you see a lot of the typical Thais wearing the useless paper facemasks, along with plain ignorance.

 

[edwardandtubs]

To be fair, I was quite impressed with how Big C and 7-11 started stocking 3M N95 masks so they're very easy to get now. Let's see if they run out this year.

[JimShorts]

49 minutes ago, TallGuyJohninBKK said:

 

The Blueair site points to Central.co.th as their official dealer in Thailand. When I went to the Central website over the weekend just out of curiosity, they listed a number of BlueAir purifiers for sale at exalted prices... but not a single Blueair filter I could find offered on their website.

 

Now, the website is not necessarily the same as the various stores. But when I've shopped for instance at Central Chidlom in the past and looked at their air purifiers there, likewise, they stocked a variety of purifier models, but carried in store few in any replacement air filters for those models. And had the same experience looking in PowerBuy in the past.

 

Last time I went to Emporium mall, Phrom Phong, they had the authentic Blueair filters in stock. 

[TallGuyJohninBKK]

7 minutes ago, edwardandtubs said:

To be fair, I was quite impressed with how Big C and 7-11 started stocking 3M N95 masks so they're very easy to get now. Let's see if they run out this year.

 

I haven't looked in Big C lately, since I have my own stocks at home. What section/department of the Big C stores is stocking them?

 

[wreckingcountry]

Fact is up until last week it has been raining in bkk every day for few weeks. And that was great despite Thais who moan about rain ! It clears the air ! Now no rain and it’s poisonous

 

 

Sent from my iPhone using Thaivisa Connect

 

[edwardandtubs]

4 minutes ago, TallGuyJohninBKK said:

 

I haven't looked in Big C lately, since I have my own stocks at home. What section/department of the Big C stores is stocking them?

 

My local Big C mini has 3M 9501 masks.

[TallGuyJohninBKK]

27 minutes ago, edwardandtubs said:

My local Big C mini has 3M 9501 masks.

 

OK... I was thinking of the larger Big C hypermarkets when you mentioned Big C... At least for the Big C hypermarkets I'm familiar with in BKK, they sometimes have some masks in their hardware section near the tools and such. But whether what they have on the aisles is N95 compliant seems pretty hit or miss.

 

[ExpatOilWorker]

14 hours ago, MaxYakov said:

NASA's Fire Information Management System (FIRMS) indicates many fires in a long and wide corridor to the north of Bangkok. Air Visual's current (0230) wind direction is from the Northeast @ 4.9 k/hr. Is this the "smoking gun". RTAQ's wind measurement/display appears to be not working:

 

Pesky farmers are destroying the pristine Bangkok air. 

What kine of indoor PM2.5 can you achieve at the moment?

I am am struggling to keep my 80 m2 place below 30 micro g/m3 with my old Hatari running flat out.

[TallGuyJohninBKK]

13 minutes ago, ExpatOilWorker said:

Pesky farmers are destroying the pristine Bangkok air. 

What kine of indoor PM2.5 can you achieve at the moment?

I am am struggling to keep my 80 m2 place below 30 micro g/m3 with my old Hatari running flat out.

 

My Sharp unit with a 1-1/2 year old HEPA filter has been keeping my enclosed, mostly sealed bedroom in the 6-9 micrograms level for most of the day. The comparable reading from another sensor in a different, unfiltered indoor room at home has been 55-60 mcg.

 

I'm trying to see how much more mileage I can get out of my current HEPA filter before I made the decision to toss it and replace with a new one. If I can't keep my indoor levels below 12 mcg (the threshold for "good" air), then it will be time to toss it.

 

[lopburi3]

11 minutes ago, ExpatOilWorker said:

Pesky farmers are destroying the pristine Bangkok air. 

What kine of indoor PM2.5 can you achieve at the moment?

I am am struggling to keep my 80 m2 place below 30 micro g/m3 with my old Hatari running flat out.

That really is too large an area for one unit.  I am having no issue keeping it between 008-010 in my 26sm bedroom today with outside at about 59 using current model Hatari at low speed 2.

[TallGuyJohninBKK]

2 minutes ago, lopburi3 said:

That really is too large an area for one unit.  I am having no issue keeping it between 008-010 in my 26sm bedroom today with outside at about 59 using current model Hatari at low speed 2.

 

The Hatari unit isn't designed to effectively clean the air for an 80 sq mt space or anywhere close to it.  From memory, I'm saying the design spec is closer to a room about half that size.

 

[MaxYakov]

39 minutes ago, ExpatOilWorker said:

Pesky farmers are destroying the pristine Bangkok air. 

What kine of indoor PM2.5 can you achieve at the moment?

I am am struggling to keep my 80 m2 place below 30 micro g/m3 with my old Hatari running flat out.

I'm maintaining 5.0 micro grams or below in a 15 m² bedroom with a second-hand Hitachi AP-E3000 purifier with an Hatari RAP-1201 HEPA filter installed. I have a 3M Filtrete pre-filter layer installed on the input side of the Hatari HEPA filter. 

 

Just measured 0.0 to 1.0 micro grams at the Hitachi's output just after replacing the Filtrete pre-filter. Got about four months use from the Filtrete pre-filter. It did a great job of stopping the big stuff - was pretty dirty. Running the Hitachi in "Purify" mode at the lowest fan speed. Keeping the bedroom door closed except for egress. Not purifying air in any other part of my apartment except the bathroom when showering/bathing. I believe I'm well-within the m² recommended of the Hatachi/Hatari combination AND the room is very well closed-off from outside, dirty air.

 

Maybe the operative word in your case is "old"? What is the state/condition of its filter? What is the specification of your purifier w/r the recommended m² room size?

 

 

[ExpatOilWorker]

5 minutes ago, MaxYakov said:

I'm maintaining 5.0 micro grams or below in a 15 m² bedroom with a second-hand Hitachi AP-E3000 purifier with an Hatari RAP-1201 HEPA filter installed. I have a 3M Filtrete pre-filter layer installed on the input side of the Hatari HEPA filter. Just measured 0.0 to 1.0 micro grams at the Hitachi's output just after replacing the Filtrete pre-filter. Running the Hitachi in "Purify" mode at the lowest fan speed. Keeping the bedroom door closed except for egress. Not purifying air in any other part of my apartment except the bathroom when showering/bathing. I believe I'm well-within the m² recommended of the Hatachi/Hatari combination.

 

Maybe the operative word in your case is "old"? What is the state/condition of its filter? What is the specification of your purifier w/r the recommended m² room size?

I just replaced the HEPA filter and cleaned the pre-filter a couple of days ago. My previous HEPA filter was 2 years old and had gained 5 grams of mass, which means it has filtered 250,000 m3 at 20 micro gram/m3.

[MaxYakov]

23 minutes ago, ExpatOilWorker said:

I just replaced the HEPA filter and cleaned the pre-filter a couple of days ago. My previous HEPA filter was 2 years old and had gained 5 grams of mass, which means it has filtered 250,000 m3 at 20 micro gram/m3.

You actually weighed your HEPA filter? I hadn't thought of that. I find that approach very interesting. I'm sure Lord Kelvin would have as well. ????

 

Anyway, how much outside air leakage into your room do you think you might have? I have an hypothesis: Barring any internal source of pollution, in a well-sealed room any reasonable purifier will EVENTUALLY clean all the air regardless of its m² size. The leakier the room, the more difficult it would be for any purifier to "keep up". It's only an hypothesis.

 

 

[ExpatOilWorker]

4 minutes ago, MaxYakov said:

You actually weighed your HEPA filter? I hadn't thought of that. I find that approach very interesting. I'm sure Lord Kelvin would as well.

 

Anyway, how much outside air leakage into your room do you think you might have? I have an hypothesis: Barring any internal source of pollution, in a well-sealed room any reasonable purifier will EVENTUALLY clean all the air regardless of its m² size. The leakier the room, the more difficult it would be for any purifier to "keep up". It's only an hypothesis.

Yes, I have a pretty accurate digital kitchen scale, so I write the weight and date on the filter as I install it. Happy you like the idea.

The balcony doors and windows are well sealed, so main ingress point are the front door. Standard indoor climate recommend 1/2 room volume replacement/hour through natural ventilation. I am probably in that ball park or about 100 m3/hour.

[MaxYakov]

9 minutes ago, ExpatOilWorker said:

Yes, I have a pretty accurate digital kitchen scale, so I write the weight and date on the filter as I install it. Happy you like the idea.

The balcony doors and windows are well sealed, so main ingress point are the front door. Standard indoor climate recommend 1/2 room volume replacement/hour through natural ventilation. I am probably in that ball park or about 100 m3/hour.

Standard indoor climate recommend 1/2 room volume replacement/hour. Where is this standard stated, if I may ask. And how are you achieving this "Standard"?

 

I'm well below the Standard you stated and am concerned about O₂ and CO₂ levels in my relatively well-sealed bedroom and understand that I have to occasionally "refresh" the room air and then clean the new air.

[ExpatOilWorker]

17 minutes ago, MaxYakov said:

Standard indoor climate recommend 1/2 room volume replacement/hour. Where is this standard stated, if I may ask. And how are you achieving this "Standard"?

 

I'm well below the Standard you stated and am concerned about O₂ and CO₂ levels in my relatively well-sealed bedroom and understand that I have to occasionally "refresh" the room air and then clean the new air.

I am actually a student of P. Ole Fanger and have my fair share of olf and decipol (https://en.wikipedia.org/wiki/Decipol). 1/2 room volume/hour was standard when calculating indoor climate and energy consumption.

During the energy crises in the late '70 early '80, houses were build so air tight and synthetic materials giving off pollutants were common used, that sick building syndromes started to appear. Ventilation was the solution and 1/2 room volume/hour was seen as sufficient.

Air gets mixed up so it is not like you replace all your polluted air in a room ever 2 hours. 

After 1 hour, half your dirty air is still there, after 2 hours 25%, after 3 hours 12.5%, after 4 hours 6.25%, etc.

Keep in mind, this is all based on the fresh air comes from outside and pollutants are generated inside the building. Kind of the opposite we are experiencing today in Bangkok.

 

I doubt you have to worry much about CO2 build up, even a well sealed room will not reach 5000 ppm CO2, which is OSHA's level for a 8 hours working day.

I actually have a Dräger Pac7000 CO2 detector, as the one below (not the H2S detector, but same model), but I haven't used it for years, so I think the calibration is off.

https://www.draeger.com/en-us_us/Applications/Products/Portable-Gas-Detection/Single-Gas-Detectors/Pac-7000

[ExpatOilWorker]

On 9/30/2019 at 6:43 PM, MaxYakov said:

Standard indoor climate recommend 1/2 room volume replacement/hour. Where is this standard stated, if I may ask. And how are you achieving this "Standard"?

 

I'm well below the Standard you stated and am concerned about O₂ and CO₂ levels in my relatively well-sealed bedroom and understand that I have to occasionally "refresh" the room air and then clean the new air.

Below are some guideline for air change rates. They list residence at 1-2 room volume per hour.

 

https://www.engineeringtoolbox.com/air-change-rate-room-d_867.html

[ExpatOilWorker]

On 9/30/2019 at 6:43 PM, MaxYakov said:

Standard indoor climate recommend 1/2 room volume replacement/hour. Where is this standard stated, if I may ask. And how are you achieving this "Standard"?

 

I'm well below the Standard you stated and am concerned about O₂ and CO₂ levels in my relatively well-sealed bedroom and understand that I have to occasionally "refresh" the room air and then clean the new air.

You mentioned earlier that your bedroom is 15 m2 or 36 m3 with a 2.4 m ceiling height.

Assuming you are the only occupant that gives you the following CO2 concentrations:

 

18 m3/hour air replacement = 1,495 ppm

10 m3/hour = 2,367 ppm

5 m3/hour = 4,334 ppm

 

The above assume normal human CO2 exhaust of 36 g/hour and 400 ppm CO2 concentration of outdoor air.

[naboo]

I've just bought some overpriced N95 masks - 270B for 3. My wife laughed at me.

 

So not to worry, knowing my luck the pollution will be gone in the morning.

[edwardandtubs]

3 hours ago, naboo said:

I've just bought some overpriced N95 masks - 270B for 3. My wife laughed at me.

 

So not to worry, knowing my luck the pollution will be gone in the morning.

Your wife was right to laugh at you. I'm currently staying up late enjoying the fresh air on my balcony.

[ExpatOilWorker]

On 9/30/2019 at 6:43 PM, MaxYakov said:

Standard indoor climate recommend 1/2 room volume replacement/hour. Where is this standard stated, if I may ask. And how are you achieving this "Standard"?

 

I'm well below the Standard you stated and am concerned about O₂ and CO₂ levels in my relatively well-sealed bedroom and understand that I have to occasionally "refresh" the room air and then clean the new air.

If we make the approximation that pm2.5 particles behave like a gas, you can indirectly calculate your ventilation rate and thereby your CO2 concentration as below:

 

Q ventilation (m3/h) = ( pm2.5(indoor) x Q HEPA (m3/min) x 60 )/( pm2.5(outdoor) )

 

The day we had 100 pm2.5 outdoor you mentioned you measured 5 micro g/m3 indoor, so if your HEPA filter were 100% efficient and running at 3 m3/min, your ventilation rate was: 9 m3/h or just 1/4 room volume/hour.

Your CO2 will over time build up to 2,586 ppm at that ventilation rate.

[MaxYakov]

50 minutes ago, ExpatOilWorker said:

If we make the approximation that pm2.5 particles behave like a gas, you can indirectly calculate your ventilation rate and thereby your CO2 concentration as below:

 

Q ventilation (m3/h) = ( pm2.5(indoor) x Q HEPA (m3/min) x 60 )/( pm2.5(outdoor) )

 

The day we had 100 pm2.5 outdoor you mentioned you measured 5 micro g/m3 indoor, so if your HEPA filter were 100% efficient and running at 3 m3/min, your ventilation rate was: 9 m3/h or just 1/4 room volume/hour.

Your CO2 will over time build up to 2,586 ppm at that ventilation rate.

Thanks. Early this morning when AQI was around 60 and the outside air was cool I refreshed my entire apartment for an hour with my bathroom's window-mounted, HEPA-filtered intake fan (cracking my balcony window a wee bit to provide an exhaust path).

 

I took measurements before and after to get a feel of how clean the incoming air was made and the end result. It was very encouraging and confirmed that a total flush could be done in only an hour to extend the life of the bathroom fan's HEPA filter. I'm using a JCG60 PM2.5/TVOC/HCHO measurement device which seems to give a very reliable/reasonable PM2.5 reading after about 20-30 seconds of stabilization. The TVOC and HCHO measurements take 200 seconds and always seem to be at an "alarm" level according to the device. I usually power it down after I get a stabilized PM2.5 reading because its battery-life is not very long.

 

If you can not measure it you can not improve it. - Lord Kelvin

 

Now the question is how much CO did I bring in with the flush? ???? (I don't know if I'm kidding on this point, actually)

 

Funny that you mentioned the behavior of PM2.5 particles because as I flushed I was wondering if that size particle was able to settle in a still-air environment and not behave like a gas (although heavier than air gases do settle, don't they?).

[seb2015]

So I was monitoring PM levels at home this morning and the purifiers were doing their job, but I noticed a spike in the levels of Nitrogen Dioxyde in the air.

 

 

I don’t have any appliance running on gas and I haven’t been cooking either so I’m a little bit puzzled by this.

 

Either way , knowing that the HEPA filters can’t get rid of NO2 gases , what’s the best method to filter that out , should I consider changing my carbon filters?

 

 

 

[MaxYakov]

36 minutes ago, seb2015 said:

So I was monitoring PM levels at home this morning and the purifiers were doing their job, but I noticed a spike in the levels of Nitrogen Dioxyde in the air.



I don’t have any appliance running on gas and I haven’t been cooking either so I’m a little bit puzzled by this.

Either way , knowing that the HEPA filters can’t get rid of NO2 gases , what’s the best method to filter that out ?
 

I guess we can presume that you were not making nitric acid, welding, using explosives or refining crude oil, yes?

 

Seriously, It's a good question. I see the Max in the last 48 hours according to the RTAQI site was 24 (there appears to be a small spike that occurred around 10AM this morning). As far as filtering NO₂ based on a single spike goes - how much time/money you got (meaning it would be time for "Google", doncha think)?

[edwardandtubs]

@seb2015NO2 pollution is a problem in the UK caused by the rise in diesel cars. Maybe someone was idling their 4x4 outside your home. There's no way of filtering it.

[edwardandtubs]

I bought an XPX purifier from Shopee for 1300 baht. It's gone up a bit to 1500 now and is also available from Lazada. It's a Thai product but maybe just a rebrand of some generic product. Anyway, it works surprisingly well. Actually, it's not surprising because we know air purifiers are just fans with HEPA filters. The pm2.5 monitor is inaccurate but I don't care as I've already got 2. Also they were supposed to send 2 free 3M masks but didn't. I didn't want them anyway so I'm not fussed. Overall, I definitely recommend it and the replacement filters are available from XPX's own Lazada and Shopee stores for less than 500 baht.

[MaxYakov]

1 hour ago, edwardandtubs said:

I bought an XPX purifier from Shopee for 1300 baht. It's gone up a bit to 1500 now and is also available from Lazada. It's a Thai product but maybe just a rebrand of some generic product. Anyway, it works surprisingly well. Actually, it's not surprising because we know air purifiers are just fans with HEPA filters. The pm2.5 monitor is inaccurate but I don't care as I've already got 2. Also they were supposed to send 2 free 3M masks but didn't. I didn't want them anyway so I'm not fussed. Overall, I definitely recommend it and the replacement filters are available from XPX's own Lazada and Shopee stores for less than 500 baht.

Wow! Such a deal! Looked at the ads for this and HEPA was not used to describe it nor was PM2.5 mentioned. Cigarette smoke, allergens and dust mites were mentioned, however. What do your PM2.5 measurement devices indicate w/r to PM2.5 at the unit's output when known high-PM2.5 air (outside Bangkok air for example) is being purified?

 

I measure this often when using my HEPA filters by placing my JCG60 PM2.5 detector directly into the filters' airflow near the filter and typically get 0.0 to 1.0 mcg/m³. 

[edwardandtubs]

34 minutes ago, MaxYakov said:

Wow! Such a deal! Looked at the ads for this and HEPA was not used to describe it nor was PM2.5 mentioned. Cigarette smoke, allergens and dust mites were mentioned, however. What do your PM2.5 measurement devices indicate w/r to PM2.5 at the unit's output when known high-PM2.5 air (outside Bangkok air for example) is being purified?

 

I measure this often when using my HEPA filters by placing my JCG60 PM2.5 detector directly into the filters' airflow near the filter and typically get 0.0 to 1.0 mcg/m³. 

It says HEPA and pm2.5 on the side of the box and seems to be just as effective as my Xiaomi 2s but I only got it yesterday so haven't tested it in heavily polluted conditions. I woke up this morning having left it on overnight and got pm2.5 readings of 0 from my Sndway.

[ExpatOilWorker]

8 hours ago, edwardandtubs said:

I bought an XPX purifier from Shopee for 1300 baht. It's gone up a bit to 1500 now and is also available from Lazada. It's a Thai product but maybe just a rebrand of some generic product. Anyway, it works surprisingly well. Actually, it's not surprising because we know air purifiers are just fans with HEPA filters. The pm2.5 monitor is inaccurate but I don't care as I've already got 2. Also they were supposed to send 2 free 3M masks but didn't. I didn't want them anyway so I'm not fussed. Overall, I definitely recommend it and the replacement filters are available from XPX's own Lazada and Shopee stores for less than 500 baht.

This model?

 

https://www.lazada.co.th/products/xpx-32-jd55-i282680782-s460471561.html?ef_id=Cj0KCQjwuNbsBRC-ARIsAAzITuc4DJSBOUfE7R08jHsKTz98NV-s32ximtV4bmcQcpvRHAvCCBN6vxUaApp4EALw_wcB:G:s&s_kwcid=AL!3152!3!286179630377!!!u!814718130886!&exlaz=d_1:mm_150050845_51350205_2010350205::12:1498579383!58089999096!!!pla-814718130886!c!814718130886!460471561!122458844!286179630377&gclid=Cj0KCQjwuNbsBRC-ARIsAAzITuc4DJSBOUfE7R08jHsKTz98NV-s32ximtV4bmcQcpvRHAvCCBN6vxUaApp4EALw_wcB