I Need to Filter a Lotta Air

July 22, 2011 4:10 PM

How can I clean the air in my open plan loft?

I have a 1500 sq ft. loft with two closed off bedrooms, so the main room is about 1100 sq ft. I'm contemplating buying a HEPA air filter of some sort, especially because there's ongoing construction in the building, and my lungs hurt when I cough.

Most of the HEPA air filters I see recommended in this old AskMe are for rooms up to 300 sq ft. Do I buy four of these suckers and keep them going all the time? Or is there something larger, yet still quiet, and ideally not too expensive to run?

Do I need to buy a HEPA vacuum while I'm at it?

Other relevant info: no pets, four humans, hardwood floors, not a smoggy city (Montreal).

posted by musofire to Home & Garden (2 answers total)

Best answer: 1) If you leave it running 24/7 and don't have a lot of external air exchange (read: leaky windows/doors/central-forced-hot-air-heat), a single large filter should do the whole space over time. Otherwise, consider just keeping one in the bedroom (with the door kept closed) and an extra one to do what it can for the rest of the house - 99% of the benefit for half the cost.

2) Make your own "pre-pre-filters" - Take a two-ply sheet of paper towels, separate the two halves of the ply(?), and drape them over the outside of the actual filter but inside its cover. Replace this every month (or more often, as reduced air-flow necessitates), and the HEPA-proper filter (the expensive part) will last easily 10x as long.

3) Consider a unit with a UV-C lamp in it. It kills everything that passes through, for only a small amount of additional electricity used.

4) Yes, buy a HEPA vacuum. Whether you need it or not, you won't regret it.


Biggest costs to consider - Large HEPA filters draw on the order of 200W, and replacing just the filter will cost about half of replacing the whole unit.
posted by pla at 4:31 PM on July 22, 2011 [1 favorite]

I have this oneand I love it. 4 speed, a timer, and it can go flat against the wall (or the end of my couch) and you can turn it so the air is directed up or to the side. It's rated for 418 sq feet, but if you run it for 24 hours and you don't have drafts anywhere it will filter the area. You could also get two and put one at each end. Holmes makes smaller ones too...I have a smaller one for my bedroom and when I shut the door and let it run a couple of hours I can tell a difference. I don't know how much electricity it uses and Holmes may not be top of the line, so that might be a concern for you. For me, I'd rather spend some extra money so I can filter the neighbors smoke, cat dander, and mold out of the air.
posted by MultiFaceted at 7:20 PM on July 22, 2011 [1 favorite]