DIY Air Purifier for just 30$

[Goetz1965 1,071]

I just stumbled upon this DIY video to make a cheap but efficient Air Purifier
I just wonder has anyone seen larger boxfans and HEPA filters like this available in Cebu-City ?

Because I plan to move back to Inayawan (as its much cheaper) but air quality is worse.
That said I would like to add a little better air indoors to bedroom and office then.
 

 

[Jester 3,618]

Interesting, however the air in an average house is exchanged every 3 hours with outside air.   So it appears it would take a very large or even multiple units to do a house.   Set up in a bedroom with the door closed while sleeping would be an idea.

What kind of box fan is that, never heard one that quiet?

[lamoe 14,557]

10 hours ago, Jester said:

Interesting, however the air in an average house is exchanged every 3 hours with outside air.   So it appears it would take a very large or even multiple units to do a house.   Set up in a bedroom with the door closed while sleeping would be an idea.

What kind of box fan is that, never heard one that quiet?

The filter causes reduced air flow and noise. https://blog.directenergy.com/check-air-filters-right-home/

Shutting the door doesn't let the cooler night air in. For us, 19th floor,  can be as much as 15  / 20 compared to street level.

Will look at getting a simple box L channel aluminum frame made - could hold up to 5 filters / blank panels and box fan for Bohol BR (2nd floor) - already have screens and grates on windows / balcony door so no problem mounting outside under 2 M overhang.

This is  neat design to reduce the effect a single filter has on air flow.

 

Quote

 

https://tombuildsstuff.blogspot.com/2013/06/better-box-fan-air-purifier.html

Air purifiers can be expensive and you've probably seen articles recommending to just put a 20" x 20" x 1" furnace filter on a cheap 20" box fan and POOF! instant cleaner air for not a lot of money. It really does clean the air pretty cheap.

There's a problem with this though. These fans weren't designed to be run with a filter. The filter will restrict air flow which will put a higher strain on the motor causing it to use more electricity and in worse cases could be a fire hazard. The higher the MERV rating (cleaning efficiency) of the filter the more stress it will put on the fan.

Don't worry! You can still have your cheap air purifier as long as the filter area is increased to decrease the effect of air resistance. Instead of using one 20x20x1 filter we'll use two 20x25x1 filters which increases the filter surface area over 250%. It's a little more expensive because you're using two filters instead of one but the increased filter surface area also helps the filter last longer before it gets clogged up and we're saving on energy use compared to a single filter.

 

 

Edited May 25, 2020 by lamoe

[+Dafey 15,247]

$39 from Lazada and much prettier. Also has negative ion generator. Will take care of a room up to 20 Sq M

or for twice the price get one that does 80 sq M

[HongKongPhooey 397]

12 hours ago, lamoe said:

This is  neat design to reduce the effect a single filter has on air flow.

If you are going to DIY, I would recommend you design it so the filters are easily removable for replacement, not all taped up like your example. HEPA filters will filter out mold spores, which you want; but with the tropical humidity, eventually that mold will start growing on the filter fibers. You are then blowing that out into the room. HEPA filters shouldn’t be washed or vacuumed because that effects their efficiency. If yours is a longer term solution, I would make it easier to switch out because then you are more likely to replace those filters frequently, as you should.

[lamoe 14,557]

10 hours ago, HongKongPhooey said:

If you are going to DIY, I would recommend you design it so the filters are easily removable for replacement, not all taped up like your example. HEPA filters will filter out mold spores, which you want; but with the tropical humidity, eventually that mold will start growing on the filter fibers. You are then blowing that out into the room. HEPA filters shouldn’t be washed or vacuumed because that effects their efficiency. If yours is a longer term solution, I would make it easier to switch out because then you are more likely to replace those filters frequently, as you should.

Air in Inabanga is relatively clean - especially in compound - just noise / odor pollution - grow chickens and  and cows and pigs , oh my.

If fan too close to screen, extreamly tiny bugs get blown / sucked through. But far enough away greatly reduces air coming in.

Agree about no tape / mold - that's why the L channel for the frame with interior corner brackets if cheap air filters used - simple wood for washable cloth.