4 ms·

It is me! I'll note that I've also done experiments comparing the effects of taping and not taping around the filters, which you can see here: https://dynomigh

by dynm 4y ago

It is me! I'll note that I've also done experiments comparing the effects of taping and not taping around the filters, which you can see here: https://dynomight.net/2020/12/15/some-real-data-on-a-DIY-box-fan-air-purifier/#taping https://dynomight.net/2020/12/15/some-real-data-on-a-DIY-box...

hcurtiss 4y ago
It's awesome that you've done all this work. I have to say, though, that this could just as well be evidence that your experiment is not designed terribly well. One would never build a home furnace with a filter that has gaps all the way around it.
- dynm 4y ago
  Certainly you wouldn't, but keep in mind the blower in a home furnace is designed to push air through a filter. This is not the case with box fans, where (at least with the filters I used) the fan throughput vastly decreases when you add the tape. I'm pretty confident in my experiments, but I wouldn't claim this as a general result: It's just a sort of coincidence that the two factors (pushing more air overall and funneling a larger fraction of that air through the filters) happen to almost exactly cancel out. If you have a more powerful fan or you have filter media that creates less of a pressure barrier, then I'm pretty sure you will see a benefit from taping. But I was just worried about the box fan motor so I decided to remove them.
- amluto 4y ago
  The purpose of these filters is entirely different. A furnace filter needs to prevent large particles from passing it, as such particles can deposit on the coil. Its utility is essentially -(particles missed). A room air purifier exists to remove particles. Its utility is (particles removed). Blowing additional air around that bypass the filter in an air purifier is harmless, whereas it can destroy your furnace or especially your A/C. This is why the IKEA air purifier is a better design than a HEPA purifier. Also people most certainly do build furnaces with gaps around the filter.
  - hcurtiss 4y ago
    This is all wrong. Our furnace filters (and all furnace filters) filter particles specifically to clean the air. And with a MERV 13 or higher rating, they even filter Pm 2.5. And, no, I’ve never seen a single furnace filter with intentional gaps around the filter.

by dynm 4y ago

hcurtiss 4y ago

It's awesome that you've done all this work. I have to say, though, that this could just as well be evidence that your experiment is not designed terribly well. One would never build a home furnace with a filter that has gaps all the way around it.

dynm 4y ago
Certainly you wouldn't, but keep in mind the blower in a home furnace is designed to push air through a filter. This is not the case with box fans, where (at least with the filters I used) the fan throughput vastly decreases when you add the tape. I'm pretty confident in my experiments, but I wouldn't claim this as a general result: It's just a sort of coincidence that the two factors (pushing more air overall and funneling a larger fraction of that air through the filters) happen to almost exactly cancel out. If you have a more powerful fan or you have filter media that creates less of a pressure barrier, then I'm pretty sure you will see a benefit from taping. But I was just worried about the box fan motor so I decided to remove them.
amluto 4y ago
The purpose of these filters is entirely different. A furnace filter needs to prevent large particles from passing it, as such particles can deposit on the coil. Its utility is essentially -(particles missed). A room air purifier exists to remove particles. Its utility is (particles removed). Blowing additional air around that bypass the filter in an air purifier is harmless, whereas it can destroy your furnace or especially your A/C. This is why the IKEA air purifier is a better design than a HEPA purifier. Also people most certainly do build furnaces with gaps around the filter.
- hcurtiss 4y ago
  This is all wrong. Our furnace filters (and all furnace filters) filter particles specifically to clean the air. And with a MERV 13 or higher rating, they even filter Pm 2.5. And, no, I’ve never seen a single furnace filter with intentional gaps around the filter.