DaveInSukhumvit

On 2/27/2020 at 12:43 PM, WalkingOrders said:

Air conditioned 

Meaning gym membership places have same AQI like outside.  I've only found 2 coffee shops in dozens of meter tests that appear to be semi purified air.  In general, nobody sells air conditioning filters here in Thailand (AFIK), especially not HEPA filters.  That means no filters for Wall-hang units, no for Cassette units (ceiling square design), no for central ducted split units.   I did see a customizable HEPA shop online one time, I think this is it: https://www.facebook.com/SRPFRESH/)   Corrections always welcome.

About humidity influence on Sndway unit...  I tested this the other day putting meter in bathroom during my shower - not much change even with fog on the mirror.  So I put meter in shower with me - then it got rather exciting.  In short, I noticed non-liner behavior when it went from humid to very humid.  Thanks to Max's PDF we can see that when humidity gets above RH 80% the PM count gets a boost from water particles.

I like this RH information on Sndway because I have noticed that the air in Au Bon Pain at Emporium Tower (M level) is usually pretty good (different from outside) suggesting filtered air.  I've tested it many times with 3 different meters.  I don't think it is RH because everything in Emporium buildings is air conditioned and relatively low RH compared to outside. Also Starbucks at Century Onnut has better air.  I'm trying to figure out why.  By contrast, Emporium food court 4th floor glass seating area is exceptionally high AQI around 200-250 at lunch.  Just FYI. Ideas welcome.

20 hours ago, Misty said:

Thanks very much for your thoughts.  Thanks to all the upgrades I've made over the last two years, most rooms in our place measure low on my Sndway meter.  Even the big room usually measures low, unless we turn on the old central air conditioners that still exist in that room. I did ask our Thai building manager about installing filters on the intake side for those units, but they said the units are too old and not the same as the US.  So we're left with either no air, or paying to replace those old units ourselves.  Will have to study this some more to see what is most cost effective.  Just getting a small portable a/c is appealing since its cheap.

Thanks for your kind words.  I'm happy that you generally get good air in your home.  About the Central AC making air worse, I've seen a lot of leaky AC Plenums (Ductwork) in the US, and I'm 1/1 (one out of one) with a simple inspection here.  They don't seal the joints.  In the case with the Thai example near Phrakhanong BTS, I just took the outlet cover off and it was quite clear that air was coming from inside the rather-large crawl space between units.

On 2/24/2020 at 8:15 AM, mtls2005 said:

AQI forecast for this week looks dismal...no clue how accurate that forecast is though.

Has anyone looked at the accuracy of these pollution forecasts, and could share an opinion?  They seem suspect to me.  As Max wrote, wind blowing East fire areas mixes with low velocity clean air from the South ocean .... and AQI suffers.   If Thursday and Friday hit Purple (~250 AQI), almost everybody starts getting sick.

I have not found a great wind forecast site yet.  I think wind forecast (velocity and direction) is key to a good pollution forecast.

On 2/24/2020 at 10:01 AM, Misty said:

Dave, been able to replace central air conditioning in most rooms in our apartment with wall units and purifiers. This works quite well for the rooms so equipped. But the last room is a large living/dining area, which still has 3 old central air conditioners which our landlord will not replace.  As soon as any of these units are turned on, the PM2.5 levels in that room immediately start to rise - so we limit their use and focus on electric fans.  Still, it can get hot. My options, as I see it, are to either replace one more more of the central units with a wall unit myself. Alternatively just get a small portable air conditioner that sits near where ever the people in that room are located.  Any thoughts on these ideas (or any others)?

Sounds like you have a big place with a lot going on.  I know the answer in the USA - air handlers usually come equipped with filters on the intake (suction) side cleaning the air before it goes into the fan aka blower.  In the US, you just put a filter in there.  If you want 4" HEPA filter, you can have AC guy rework the sheetmetal to include that larger filter.

Sorry, but I don't know much about Thai installations.  Many condos/apartments/homes I have seen are leaky.  I would start with a inexpensive meter to see how the inside air is compared with outside (with purifier running).  Sndway meter is fine, but not shipping from China right now AFIK.

On 2/17/2020 at 12:41 PM, seb2015 said:

That's a very nice app , I wonder how future predictions can be accurate ?

I can see that the next date at which wind should blow from the gulf onto the capital is next monday , too bad , I really enjoyed the weekend .

Hopefullly we're nearing the end of the burning season 

 

 

Side question : does anyone have experience with centrally distributed aircon systems (i.e. VRV) and how easy it is to insert PM2.5 / HEPA filter pads in the main air pipe ?

We're building a house in the city and this looks like a more expensive setting vs individual aircon units in all rooms, but if it allows me to worry less about purifying the air in every room , I'm down with this option..

 

Re "end of burning season" - AFIK, the waste-to-energy plants around BKK don't have a season. The coal power plant in the South doesn't either.  Also garbage burning, plastics burning, and electronics recycle/burning are a problem only abated by wind direction or govt order.  If you believe the news, then contracts for importing containers of plastic from other countries expire at the end of 2020, so that should help with dioxins, etc..

Re: central air systems and filters - I did a central system installation in Florida as a hobby for an add-on.  So I'm no expert, but more than a little hands-on.  In US it is easy to find the 4" thick hepa filters of all shapes and sizes at home depot, lowes, etc.  Do a google image search on "20 in. x 25in x 4.375 in. Pleated Hepa filter" to see.  Here in BKK, Home Pro does not stock any comparable hepa filters (only Hatari Rap 1201, or Filtrete).  The lack of availability is a concern.  I suspect, in time, there will be options - but unless someone knows better, they are few and far between at the moment.

If you did have a HEPA source for large filters, then a 2000 - 3000 sq ft home with 2-4 BR could be cooled with one central AC unit - they do it all the time in Florida.  But those spit systems require a large pad outside and air handler inside.  I think it is far less expensive to go with Purifiers in every room.

.. Improvements welcome ????

On 1/20/2020 at 9:15 AM, Fore Man said:

 

21 hours ago, TallGuyJohninBKK said:

 

Wonder if you can elaborate on your above comments a bit?

 

In particular, I'm not aware of any true HEPA filtration that can be added to an existing split unit air con system that didn't come with its own manufacturer provided HEPA filtration filters, as some of the newest air cons have.

 

If you mean adding 3M Filtrete sheets, those don't provide HEPA filtration, though they would be better than just the standard plastic screen type filters that most AC units come with. Plus, 3M advises against covering the entire filter surface area with their Filtrete sheets, and leaving open surface area as recommended reduces the filtering capability even further.

 

Thanks for a couple of great posts

On 1/20/2020 at 9:15 AM, Fore Man said:

PM2.5 and larger particles can easily enter into a home unless it has been hermetically sealed. Here in Chiang Mai we went as far as to stop using our leaky front door entrance, taping over all the seams abutting the jambs, and started using a side door from the garage. That door led into an anteroom which we could use as a barrier of sorts from the rest of the home. I added flexible silicone strips to the bottom of all doors to seal off that small gap that allowed air to flow into rooms. We taped over all window casings too and I found that these measures did improve our AQ somewhat.  The plain truth is that even after we took the extreme steps as I did, our home still leaks like sieves and the only really useful preventative measure we can take us to run air purifiers 24/7. We added HEPA filters to our ACs or learned how to correctly set our units already equipped with such filters. By doing all these things, the PM2.5 readings in our home were reduced from the 80s+ down to single digits. We employed Xiaomi purifiers, but their displays only show PM2.5 concentrations and not total contaminants in the air. But I can assume that by greatly lowering PM2.5, we are also lowering the total contamination as well.

 

Thailand refuses to get its act together and enforce laws already enacted.  People here will continue to pollute and burn everything they can with no regard for the impact on their own health, much less that of their families, neighbors and fellow citizens. We came to the difficult realization that the only meaningful action we could take was to pack up and leave for a more wholesome place to live.  It is not hard to predict the future for the Thai populace, one in which hundreds of thousands, if not millions, will suffer from lung and heart diseases, early onset of emphysema, cancer and cardiovascular problems. Mortality rates will reflect this extreme shortsightedness of the government and its people to prevent the inevitable tragedy that will befall this kingdom. When you see medical doctors leaving their jobs and take up positions in cleaner locales, then you realize just how bad things are. I bid you all good luck and for those of you who chose to, or are forced by circumstances to stay, I encourage you to take every preventative measure that you can.  If you can leave then do it and don’t procrastinate. Don’t be put off by wearing a mask when nobody else will.  It’s your life and your health at stake.  The Thai government could care less for whatever medical dangers they are forcing on its people and its guests through their ineptitude and apathy. But you can act on your own behalf...and you must. 

Thanks for a great post.