Filtrete air con filters -- I've been doing it wrong?

[wpcoe]

In another section someone posted a video about how to install Filtrete air con material:

 

 

Is it really better to leave that much of the filter screen free of the Filtrete material?  i.e. How much air flow reduction is caused by covering the entire surface?  For years I've been covering the entire surface of the air con filter screen.

 

I've been gluing the filter material to the front of the air con filter screen.  Is there any benefit to looping it behind to glue it to the back on the top?

 

I do understand and like the idea of looping the filter under and behind the bottom and letting the filter retaining tabs hold the whole thing in place.

[Crossy]

It does seem counter-intuitive, air, like any fluid, will take the path of least resistance, i.e. around the filtrete.

 

What do the instructions say?

 

 

 

[perthperson]

8 minutes ago, Crossy said:

It does seem counter-intuitive, air, like any fluid, will take the path of least resistance, i

 

You Sir are very polite!  

 

The truth is that filter is never going to effectively filter very much ! 

[Crossy]

17 minutes ago, perthperson said:

You Sir are very polite!  

The truth is that filter is never going to effectively filter very much ! 

 

I have an ulterior reason.

 

Comment on the YouTube video allegedly from 3M India;-

 

Quote

Our lab test data shows that when the AC filter is used as recommended, i.e. covering about 70% of the air inlet area, the airflow reduction is small (10 – 15%).

As the airflow decreases, the exit air temperature would infact further decrease slightly, which would help cooling, not reduce it.

Overall, if the AC filter is used as recommended and replaced frequently, its impact on cooling is minimal. Do let us know if we can help you in any other way.

 

There will be some flow through the denser filtrete, I suppose the idea is that it removes the ultra-fine particles a bit at a time as the air circulates multiple times through the aircon.

 

Or it could be complete carp.

 

If the airflow is fine with a complete covering of filtrete then it will work best like that.

 

[perthperson]

Just now, Crossy said:

Comment on the YouTube video allegedly from 3M India;-

 

I know a scientist who works for 3M    I am sure she will happily assist my understanding of how her Companies filter works !!

 

I am going to enjoy this especially when she be forced to buy the beers !  

[Kinnock]

39 minutes ago, Crossy said:

It does seem counter-intuitive, air, like any fluid, will take the path of least resistance, i.e. around the filtrete.

 

What do the instructions say?

 

 

 

Agree - most the air will go around the filter.  The electro-static effect may help a little by attracting dust - but for this to work without obstructing the airflow, I think it would need a mesh-design for the filter.

[RichCor]

...then why don't they just punch micro-holes in the center but cover the entire surface?

 

Luckily the reduced air flow from a filter only affects the fan, and not the rest of the cooling system. 

[sfokevin]

3 hours ago, perthperson said:

 

You Sir are very polite!  

 

The truth is that filter is never going to effectively filter very much ! 

They must filter something as they turn dark gray after a couple weeks use...

[perthperson]

1 minute ago, sfokevin said:

They must filter something as they turn dark gray after a couple weeks use...

 

Guess that reduces their efficiency !  How often do you replace these choked filters? 

[sfokevin]

11 minutes ago, perthperson said:

 

Guess that reduces their efficiency !  How often do you replace these choked filters? 

I'm in Chiang Mai and during the burning season I change weekly and also run stand alone air filters that are cleaned weekly as well... the rest of the year I don't use either..

 

I also so have all the AC power cleaned inside & outside twice a year - once being after the burning season

Edited July 5, 2017 by sfokevin

[eyecatcher]

Fitrates on air cons are very popular up here in Chaing Mai/Chaing Rai in March every year.

and yes they can turn black with particle matter in days.

 

Many people feel bound to suffer and remain in their accomodation for this very bad month of smog so try many things to reduce the effects.

 

I shouldn't think there is a need for people living in other parts of Thailand to take such measures.

[perthperson]

40 minutes ago, sfokevin said:

I'm in Chiang Mai and during the burning season I change weekly and also run stand alone air filters that are cleaned weekly as well... the rest of the year I don't use either..

 

I also so have all the AC power cleaned inside & outside twice a year - once being after the burning season

Wonderful ! Good for you but what a pity you missed out on the humour at the head of this thread. 

 

Are humour transplants available in CM ? 

[eyecatcher]

16 minutes ago, perthperson said:

Wonderful ! Good for you but what a pity you missed out on the humour at the head of this thread. 

 

Are humour transplants available in CM ? 

Only British humoUr is permitted on here.....no one else  has that ability; hence me  also missing out on the humour; good try tho

[sfokevin]

Filtrete is serious business in Chiang Mai... 

[trd]

The other option is not to move to CM and live in a smoke zone.

 

 

[wpcoe]

12 hours ago, Crossy said:

It does seem counter-intuitive, air, like any fluid, will take the path of least resistance, i.e. around the filtrete.

 

What do the instructions say?

 

You got me.  Anybody care to translate?

 

 

The photo in the instructions for step 2 seem to indicate I've been doing it correctly.  I notice that the YouTube video seems to be produced by 3M/Filtrete in India.  Maybe the laws of physics are different over there?

 

Something that has always made me curious, too:  There is that small "indicator" piece which has a circle of filter material a couple cm in diameter.  You're supposed to put it on the front of the air con case front, like in picture #3 to let you know when the filter material inside the unit is dirty enough to be replaced.  i.e. When you see the circle of filter material turn gray/black, the filter material inside is the same.  How likely is it that the relatively tiny area of filter material on the indicator will match the condition of the inside which is covered 100%?  Again, wouldn't the vast majority of the dirty air enter the air con unit *around* the indicator, leaving it relatively white/clean?  

[VocalNeal]

I'm thinking as they don't know exactly the pre-filter size of every AC unit they make a standard size product that sort of fits all. 

 

The rest is simply. 

[carlyai]

I know I'm Australian, so this maybe a wrong thought.
If the air is moving faster round the outside of the filter, couldn't this have a venturi type effect on the air moving through the filter, and pulling most air through the filter?
This would explain the dot in the middle as well as not covering all the filter.

Sent from my SM-J700F using Tapatalk

[impulse]

The partial coverage advice makes sense for an add-on filter material.  

 

If your A/C airflow is high enough to cycle the air several times an hour, even if only 10% of the air goes through the Filtrete, you're still filtering all the air several times a day, while not impeding airflow and cooling.

 

The A/C would operate close the design CFM, and even if the Filtrete plugs up completely, the A/C is still going to work properly.  At 100% Filtrete coverage, the air flow would go very low when the Filtrete plugs up completely- definitely diminishing the cooling efficiency and possibly damaging the works due to low air flow.

 

[wpcoe]

23 hours ago, carlyai said:

I know I'm Australian, so this maybe a wrong thought.
If the air is moving faster round the outside of the filter, couldn't this have a venturi type effect on the air moving through the filter, and pulling most air through the filter?
This would explain the dot in the middle as well as not covering all the filter.

Sent from my SM-J700F using Tapatalk
 

 

21 hours ago, impulse said:

The partial coverage advice makes sense for an add-on filter material.  

 

If your A/C airflow is high enough to cycle the air several times an hour, even if only 10% of the air goes through the Filtrete, you're still filtering all the air several times a day, while not impeding airflow and cooling.

 

The A/C would operate close the design CFM, and even if the Filtrete plugs up completely, the A/C is still going to work properly.  At 100% Filtrete coverage, the air flow would go very low when the Filtrete plugs up completely- definitely diminishing the cooling efficiency and possibly damaging the works due to low air flow.

 

Interesting points.  (Carlyai:  why would being an Aussie be a factor??)

 

My use, and this may not be typical of many (most?) Filtrete users, is to not only filter the air in the room, but to keep airborne "junk" from entering the bowels of the air con evaporator.  Having a moderate amount of air not being filtered means that a moderate amount of dirt, dander, pet hair, whatever is being lodged in the evaporator coils and fins, no?

 

At my last condo, I used Filtrete in the air cons from the day they were new and several of the air con service guys sent out over the years said there really was no need to power spray the wall unit as it was so clean inside.  (I still made them do it.  I was paying them to, so why not?)

[weary]

On 7/6/2017 at 2:49 AM, wpcoe said:

You got me.  Anybody care to translate?

 

 

The photo in the instructions for step 2 seem to indicate I've been doing it correctly.  I notice that the YouTube video seems to be produced by 3M/Filtrete in India.  Maybe the laws of physics are different over there?

 

Something that has always made me curious, too:  There is that small "indicator" piece which has a circle of filter material a couple cm in diameter.  You're supposed to put it on the front of the air con case front, like in picture #3 to let you know when the filter material inside the unit is dirty enough to be replaced.  i.e. When you see the circle of filter material turn gray/black, the filter material inside is the same.  How likely is it that the relatively tiny area of filter material on the indicator will match the condition of the inside which is covered 100%?  Again, wouldn't the vast majority of the dirty air enter the air con unit *around* the indicator, leaving it relatively white/clean?  

In the middle section, the lower bullet point in the right hand column is relevant to the discussion, but offers no in-depth explanation:
"In case the air conditioning unit is small, or designed for low air circulation, we recommend trying to install Filtrete on approx. 50-60% of the dust filter surface."

Edited March 27, 2018 by weary

[wpcoe]

@weary:  Thanks for the interpretation.  I think I'll stick with covering 100% of the surface, since I don't consider my aircon unit to be small, and don't think it's designed for low air circulation.

[mitebbots]

where can I buy 3M Filtrete in Bangkok? seems most are out of it. 

[sometimewoodworker]

3 hours ago, mitebbots said:

where can I buy 3M Filtrete in Bangkok? seems most are out of it. 

I got mine from Lazada 

[wpcoe]

Not sure about Bangkok, but in Pattaya the Home Pro stores sell it.  Some Tesco Lotus stores, too.

[Lorry]

Neither 3M official store in shopee or Lazada nor the 3M website list Filtrete aircon filter.

You can find many knock-offs in shopee/Lazada, and 3M website shows some aircon filter which doesn't carry the name Filtrete.

 

Is there a substitute?