DIY your own HEPA Air Purifier 

I like that design and I already have a duct fan to spare. If you wanted too you could cover the filter with some type of mesh. Flexible plastic, metal, or porous fabric.

The fan uses less power because it HAS less power which also makes it more quiet. Without measuring the air flow per anything (power/noise/...) it is impossible to judge how good this idea is. The provided link has a warning: "Please note this booster fan cannot be used standalone in high static pressure applications". And the filter, being H13 probably needs some 240Pa to work. I'd say for most axial compressors that is too much, especially when they operate below their max RPM which further decreases their maximum pressure, often below 100Pa. So in summary it might kinda work but probably not better than other solutions. In general it is lacking numbers.

I made a previous post to recommend that you not use this set up because it causes the motor to slow up and than makes the motor overheat when using a HEPA filter. Also, the info regarding the booster fan states that it cannot be used in stand alone high static pressure applications; which is what this setup is with the HEPA filter. I could not find a round non-HEPA filter so I returned the products in this setup. I purchased a Levoit Core 300 air purifier listed for $99.99. The filter is smaller than the one used in this setup, but the motor is the appropriate size to pull the air through the HEPA filter without it heating up. I like this idea and that is why I tried it, but the motor sizing is not appropriate for the HEPA filter which could be a potential fire hazard.

Awesome idea! Does it still work? Can you a do a test? With it on max setting, hold a piece of printer paper by the corner above it and measure how far above the fan the paper will stay horizontal from the air blowing up under it. Then we can get an idea of how much air it outputs compared to our purifier. And for suction, cover half the filter with a bag or paper, and then hold the paper from the top so it's hanging down parallel to the filter, and slowly move it towards the filter and measure how far before it begins to suck towards the filter, and how far before it sucks right onto the filter.

ive been looking for something like this! thank you for posting and providing links

Awesome

Pretty girl. Going to use the same setup but with carbon filters on top and bottom. You could use a hepa on intake side and carbon on the exhaust to remove odors and very fine particles.

I thought that this was a great idea and I purchased these products. I found that the blower motor slows down and overheats because it is not strong enough to pull the air through the HEPA filter. I fear that the overheating will start the motor on fire; for this reason I do not recommend using this set-up with a HEPA filter. I will look for a filter that is not a HEPA filter or return the products.

Thanks Emily I have asthma and am very sensitive

Great idea Emily. I would like to build something similar. Since the fan isn't really attached or sealed against the filter, do you think all of the air drawn by the fan is travelling through the filter? Or is it possible that you're getting air drawn in from around the filter / fan seal ?

How loud are duct fans?