Quote:
Originally Posted by GLOW
if you're having trouble sourcing and you don't mind, you can bojang one on the cheap
http://www.youtube.com/watch?v=kH5APw_SLUU
this is essentially what one is. you can add charcoal filter for smells, etc in addition to HEPA. personally i prefer a tunnel fan that can suck/push air in a direction vs a regular box fan but i know someone that did this and seems to work for them.
*edit*
my fav is the top comment about a lab coat and wall of books so you know it's legit  |
That is not a HEPA filter. Nowhere on the packaging does it say HEPA, for one. It's a MERV 13 pleated filter, certainly much better than your standard MERV 7/8 pleated filters, but not HEPA. It's also installed incorrectly as the pleats are supposed to be vertical, not horizontal. In humid environments, this could cause the filter media to sag over time, reducing effectiveness. Installing the filter on the upstream side of the fan and sealing around the outside of the filter would improve the effectiveness of the filter as well. What about fan selection? Does the fan chosen generate enough static pressure to adequately overcome the pressure drop across the filter, especially once it's loaded? With the filter installed, how much flow is getting through? How many air changes per hour for your room (aka how large of a room will it reasonably filter)?
His test is also terrible as it's only measuring what's coming directly off the filter, which unless your face is directly in front of the filter the whole time, means nothing. What matters is how effectively it can reduce the ambient particle count within the space.
When we're doing HEPA testing at work, the way he does it is fine because we know we're pushing 12-30 air changes per hour, so any ambient particles are going to get pushed out of the space in 2-5 minutes and replaced with 100% HEPA-filtered outside air. He's testing a system that is 100% recirculation with an unadvertised amount of flow.