Of course. I think I got the last Merv 13 in LA. :)
Yep. The best Ideas I've seen use a V shaped configuration to double the surface area and air flow.
I've used a lot of portable air filters, but the total air flow is limited, and yes, they are pretty noisy.
Regarding this DIY box fan, if I understand you correctly: duct tape a high quality filer to the back of the box fan, insuring all air must go through the filter. Then turn the fan on and let the MERV13+ do its thing.
Yep. The best Ideas I've seen use a V shaped configuration to double the surface area and air flow.
I've used a lot of portable air filters, but the total air flow is limited, and yes, they are pretty noisy.