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I have two purifiers currently. A Honeywell 50250 HEPA. And a 12x12 inch MERV 13 filter I taped to an Amazon Basics fan for DIY. I didn't expect the latter to be great, but I thought it was doing something. Now, I have my doubts.
A few days ago, office measured PM 7, I ran my DIY. After 45 minutes PM was 2, woo? But then it stayed for the next couple hours, so I'm not sure that wasn't just air variability.
Today, PM was 6+; with the Honeywell, it was 0-1 within 15 minutes. (I'm not sure my QingPing can measure <1 without wobbling.) Later I paid more attention, and even on low mode, PM was under 1 in 10 minutes.
Then I wondered how my DIY would do against high load. I fried one strip of bacon... and overshot; PM went to 999, which as high as my monitor goes. Oops. I moved the DIY in, closed the door, and waited. After 20 minutes, it was down to 893, and I wasn't sure if that wasn't just leakage/escape. Thing is, the kitchen area isn't that big (though that's complicated by literal holes in the interior walls.) 1000 cubic feet and 40 cfm should still cycle most of the air in 25 minutes, and hopefully reduce PM by like half (MERV 13).
Then I tried the HEPA. After just 1.5 minutes PM was 750. 9 minutes, 200. Whoosh.
I wondered if maybe DIY had done the hard work of getting under 999. Switched. 6 minutes, PM maybe went from 155 to 148. What if I ran nothing? 10.5 minutes, 148 to 140. So the DIY is maybe doing something, but just 2x natural leakage.
I then worried if the HEPA was biased: it blows straight up, and my monitor was on top of the fridge, near the stream. So I moved the monitor, and numbers stalled for a bit, but still, 140 to 48 in 5 minutes.
Honestly, given the volume and CFM, the Honeywell seems maybe too slow: it should be cycling the air every 4 minutes, and through a HEPA filter! But it's undeniably faster than this DIY.
A well made DIY, like a Corsi-Rosenthal box fan, is said to be very powerful, like 250 or even 400 CFM, for cheap. Maybe, but I sure didn't touch that. And if I ever do build another one, I'll want to test it, just as you should fit-test respirators. I wonder if I can get a particle source other than frying something or making popcorn.
Relatedly, I ordered a Levoit Core 300, for use in another room, and future travel. _Then_ I signed up for Consumer Reports, to read their air purifier reviews. They gave it low numbers... but also, I was not impressed with their reviews. They give high ratings to big purifiers with low CFM/$. They don't give precise numbers of their own, like CFM ACH or CADR. The more detailed Levoit reviews actually seemed great -- bunch of pro, no cons. So why the mid ratings? Totally unclear Also one of the reviews said "rated for 0 square feet" which uhhhh.
Where's the site that will tell me if CR has gone downhill?
A few days ago, office measured PM 7, I ran my DIY. After 45 minutes PM was 2, woo? But then it stayed for the next couple hours, so I'm not sure that wasn't just air variability.
Today, PM was 6+; with the Honeywell, it was 0-1 within 15 minutes. (I'm not sure my QingPing can measure <1 without wobbling.) Later I paid more attention, and even on low mode, PM was under 1 in 10 minutes.
Then I wondered how my DIY would do against high load. I fried one strip of bacon... and overshot; PM went to 999, which as high as my monitor goes. Oops. I moved the DIY in, closed the door, and waited. After 20 minutes, it was down to 893, and I wasn't sure if that wasn't just leakage/escape. Thing is, the kitchen area isn't that big (though that's complicated by literal holes in the interior walls.) 1000 cubic feet and 40 cfm should still cycle most of the air in 25 minutes, and hopefully reduce PM by like half (MERV 13).
Then I tried the HEPA. After just 1.5 minutes PM was 750. 9 minutes, 200. Whoosh.
I wondered if maybe DIY had done the hard work of getting under 999. Switched. 6 minutes, PM maybe went from 155 to 148. What if I ran nothing? 10.5 minutes, 148 to 140. So the DIY is maybe doing something, but just 2x natural leakage.
I then worried if the HEPA was biased: it blows straight up, and my monitor was on top of the fridge, near the stream. So I moved the monitor, and numbers stalled for a bit, but still, 140 to 48 in 5 minutes.
Honestly, given the volume and CFM, the Honeywell seems maybe too slow: it should be cycling the air every 4 minutes, and through a HEPA filter! But it's undeniably faster than this DIY.
A well made DIY, like a Corsi-Rosenthal box fan, is said to be very powerful, like 250 or even 400 CFM, for cheap. Maybe, but I sure didn't touch that. And if I ever do build another one, I'll want to test it, just as you should fit-test respirators. I wonder if I can get a particle source other than frying something or making popcorn.
Relatedly, I ordered a Levoit Core 300, for use in another room, and future travel. _Then_ I signed up for Consumer Reports, to read their air purifier reviews. They gave it low numbers... but also, I was not impressed with their reviews. They give high ratings to big purifiers with low CFM/$. They don't give precise numbers of their own, like CFM ACH or CADR. The more detailed Levoit reviews actually seemed great -- bunch of pro, no cons. So why the mid ratings? Totally unclear Also one of the reviews said "rated for 0 square feet" which uhhhh.
Where's the site that will tell me if CR has gone downhill?