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Kels316 / DIY-Air-Purifier

A small DIY air purifier using off-the-shelf components for under $100
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Instructions needed for filter maintenance #4

Open alfredosola opened 4 years ago

alfredosola commented 4 years ago

When the device has been running for a while, it is reasonable to expect that the filter will become increasingly clogged, efficiency will drop, and eventually perhaps particles would become afloat when the fan stops.

I think instructions should be added regarding:

  1. The expected lifetime of a filter
  2. Whether the filter can be cleaned or not, and how to do it safely (water immersion?)
  3. How to assess the status of a filter
  4. Handling of a filter that ended its life

I regret that I can provide questions but not answers. Hoping someone can chime in.

Nospamas commented 4 years ago

From experience running an off the shelf air filter for the last couple of years, this one specifically:

https://www.homedepot.com/p/Winix-FresHome-Model-P300-True-HEPA-Air-Cleaner-with-PlasmaWave-Technology-113100/205445246

Slightly out of order as it makes more sense to answer the questions this way:

  1. HEPA filter is changed out once per year. This obviously will vary depending on flow rate, environmental conditions and whether you can add a pre filter. What you're looking for is good air flow such that the air filter continues to exchange a large portion of the air in any space, once the flow rate is reduced over time this will no longer happen. I'm not sure that this duration can be assessed without testing the filter in operation.
  2. Over time the filter will become noticeably browner with small particulates. As the filter becomes more clogged with dust you'll see a reduction in flow rate.
  3. Washable HEPA filters do exist, though I can't find any information from the specific one chosen in this guide suggesting that this is so.
  4. Carefully bagging the used filter so as to not knock too many particulates back into the air and simply throwing it out seems to be the standard method for non reusable filters. Again, no suggestion that the chosen filter is reusable or recyclable, though I'd be happy to be corrected.

Finally: As noted in part 1 extension of the filters life might be achieved by adding a larger non-HEPA filter. In the commercial model we use this is achieved by a much larger mesh filter in front of the HEPA, does a good job of filtering out large particulates such as pet hair or dust bunnies.