I love our #corsirosenthalbox (all 4 of them) but Filtrete MERV 12-13 prices increased so much that it doesn't seem like a cost-effective option anymore. It was cheaper for us to buy new HEPA air purifiers (recs via guide from @cleanairstars) than to buy replacement filters for the CR boxes--even with differences in clean air delivery rate (CADR) and HEPA filter cost considerations included.
@crosscutanne @ywlebo correct, which is why $/CADR under required noise levels is so important eg US under 45dBA https://docs.google.com/spreadsheets/d/17j6FZwvqHRFkGoH5996u5JdR7tk4_7fNuTxAK7kc4Fk/edit#gid=1662890714&fvid=1567673968
(Google filterviews must be veiwed on a non-mobile browser)
3m Filtrete have always been unusually expensive for Merv 13. Lot of decent brands that can be had cheaper. Still, I somewhat view Corsi boxes as a temporary crutch earlier in the pandemic. I've replaced all but one of mine with Levoit HEPA units since. So much easier to clean/replace a cylindrical filter than rebuild a box.
Easy maintenance and space saving designs became more important to me over the course of the pandemic.
@Infoseepage @ywlebo to be sustainable you need solutions that have very low noise levels, take up little floor space, and can be scheduled for time and/or fan speed.
@Infoseepage @ywlebo The other thing about the Filtrete 1900 however is that it’s tightly pleated meaning a larger surface area (possibley longer life) and at 0.3um it may have a higher efficiency than the others (possibly 80-90% vs 50%)
@cleanairstars @ywlebo Oh, I'm a fan of the Filtrete line to be sure. I built a 20*30*1" unit using MPR 2800 filters and it was by far the longest lasting Corsi box I've built. Really appreciate the rigidity due to the metal mesh cross-bracing. I just don't know if I'd recommend them to say a PTA looking to outfit their kid's classrooms.
@cleanairstars @ywlebo All my Corsi boxes are quieter and move more air than my HEPA filters, although I wonder at the equivalent CADR. I usually run my HEPA filters one step back from the max speed for noise reasons and bump it down one further for when I'm watching TV/movies.
I like the monitoring/automation aspects of my Levoit 400s/600s units but it is not a deal breaker for me as I run them 24/7.
@Infoseepage @ywlebo @cleanairstars how does cost of filter replacements *compare*
@mackayim2022 @Infoseepage @cleanairstars Currently (U.S.), a HEPA filter for a TaoTronics device ($50-$70 for the machine) is $26, so ~$52 per year assuming I replace it every 6 months. The 3M Filtrete 2200 (MERV 13) filters, on the other hand, are ~$85-$92 for a pack of 4 (to make a 20"X20" CR box; 12"x12" size still ~$90 for x4). It took a whole year for the Filtrete filters to look gross on the CR boxes, but it would still cost more to redo a CR box than replace HEPA filters more frequently. While the large CR box (20") has greater CADR than the TaoTronics, I think it is comparable to my smaller 12" CR boxes.
@mackayim2022 @ywlebo @Infoseepage @cleanairstars In Australia we can’t get the Taotronics device mentioned-no one is selling it despite it being small, affordable, & v effective. CR boxes (at least ‘North American’ 20 inch style) also carry significant cost (with sourcing MERV-13 filters being expensive/non-trivial). Overseas the Taotronics seems a clear winner, here in 🇦🇺 the trade-offs are tricky (cleanairstars.com the best reference to compare options)
@thoughtsofawho @mackayim2022 @ywlebo @Infoseepage There may be better box fan style options in Australia using fans that move more air with less noise, but haven’t come across one yet that has been adequately assessed with either a flow capture hood or chamber test. Will have to add some computer fan options since we know they have been assessed by people like @robwiss
@mackayim2022 @cleanairstars @thoughtsofawho @ywlebo @Infoseepage @robwiss I can probably do a better job of making it clearer that @cleanairstars is me 🥸. The Twitter profile never had enough space, but thankfully Mastodon profiles do.
@mackayim2022 @cleanairstars @thoughtsofawho @ywlebo @Infoseepage @robwiss Don’t want to barrage people following me on my main account with endless air cleaning content.
@mackayim2022 @Infoseepage @ywlebo Here are total cost of ownership comparisons with three
Samsung devices (including electricity costs assuming 40hrs/week) over 1 and 3 years and 12 or 6 mthly replacement schedules for one Australian CRBox (only one 50cm box fan available and it's noisy and low performance). https://docs.google.com/spreadsheets/d/12KCvNVdZCfjwt92bVS0pFiNt4pJmtAzskSnJj_5rnNc/edit?usp=sharing
@cleanairstars @mackayim2022 @Infoseepage @ywlebo
This spreadsheet has fitters being replaced monthly for the #CorsiRosenthalBox while the recommendations are to run until the filters are visibly blackened & dirty.
I have filter boxes needing replacement at 9 months, and others over a year and still okay. This will dramatically change your estimated costs, and waste.
@BkPhilanthropy @cleanairstars @mackayim2022 @ywlebo @corsirosenthal
I haven't personally seen a need to replace Merv 13 filters sooner than about every 6 months and some of the better ones in excess of a year.
@Infoseepage @BkPhilanthropy @mackayim2022 @ywlebo @corsirosenthal It entirely depends on the type of environment they are used in (open vs closed windows), hours of use per week, and the nature of the air quality that may rapidly impact electrostatic filtration capacity (eg bushfires, cigarettes etc)
@BkPhilanthropy @mackayim2022 @Infoseepage @ywlebo @corsirosenthal
The two options are 12 Monthly (once per year) and 6 Monthly (Twice per year). Have changed the subheading to be less confusing.
@ywlebo @cleanairstars It seems to me that prices of commercial and DIY purifiers are getting closer. But as you know it is not just price but the intersection of CADR and dB and price.