4 ms·

Yeah, #1 definitely, also just skip outdoor exercise this week. You can build a cheap but effective filter with a box fan, duct tape and a furnace filter.

• channel_t 3y ago
  The only catch there might be is actually being able to find a furnace filter on store shelves during these AQI disasters. They have a tendency to quickly vanish much like toilet paper during the beginning of covid or A/C units during heatwaves.
• gabereiser 3y ago
  You can do the same with regular air filters for your HVAC. Buy 4 that are square, the size of the box fan. Put the 4 filters on end into a box. Put it on the floor or cardboard bottom. Place the fan on top blowing into the box. Obviously, duct tape the filters where they meet to keep the box from collapsing. https://www.digitaltrends.com/home/how-to-make-a-box-fan-air-purifier https://www.digitaltrends.com/home/how-to-make-a-box-fan-air...
• seadan83 3y ago
  Ait is bad enough, skipping indoor exercise is probably best unless running a quality air filter. My learning of that was after taking days and once weeks to recover from smoke exposure. I don't think the gravity of how bad it is really sinks in until the super long recovery is observed
• nerdponx 3y ago
  I tried this once but the fan didn't seem like it was capable of pushing sufficient air through the filter to do anything. I remember I looked up a bunch of articles on this to make sure I was getting the right kind of filter, and it still didn't work well.
  • rampant_ai 3y ago
    Most box fans will struggle with a single filter right up against them. The blade design on a typical box fan is designed for velocity, not pressure. Also, I don't know the physics as to why, but you want to be pulling air through the filter rather than pushing. It's why car radiators have the fan on the engine side. The best setup is to use multiple filters arranged in a box shape, since more filter surface area = less restriction on air flow. There's some great examples here: https://cleanaircrew.org/box-fan-filters/ https://cleanaircrew.org/box-fan-filters/
    • deleted 3y ago
      [deleted]
    • channel_t 3y ago
      The primitive "filter taped to box fan" model worked fine for me in Portland during the massive fires of 2020. Maybe not the greatest thing for the fan, but my indoor AQI sensor would go from reading like 250+ to under 100 pretty quickly. And of course, the filters basically turned black in a short period of time.
    • Tade0 3y ago
      > Also, I don't know the physics as to why, but you want to be pulling air through the filter rather than pushing I guess pulling seals the gap between the fan and the filter and pushing only widens it.
    • themaninthedark 3y ago
      When you are pushing air, you are building a high pressure zone. When you are pulling, you make a low pressure zone. As the pressure in front of the fan builds up, it starts to push back against the blades of the fan until it reaches an equilibrium.
  • reportgunner 3y ago
    > pushing sufficient air through the filter to do anything Sounds like you built it wrong, it's supposed to pull air through filters, not push it.