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Build a do-it-yourself home air purifier for about $25

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Re: Build a do-it-yourself home air purifier for about $25

#141

Important tip: if you set up an air purifier in your home, make sure to plug all drafts around your house: windows, doors, etc. Even a DIY purifier with small airflow can make your indoor air excellent if given enough time to do so and no leaks to fight against. If you want to get some fresh air in your home, do not leave a window half-open all day long—instead, open all your windows at once to cycle the air as fast…

This is great! Thanks for sharing :)

Re: Build a do-it-yourself home air purifier for about $25

#142
post #25

I was looking up air quality monitors but can't seem to find any on amazon with a calibration certificate that will accurately measure 0.3 micro particles. Am I the only one who thinks this is a great opportunity for a smart product with an app that has the features of a professional air quality monitor and simple UI / UX? If such product exists, does anyone know where I can find it?

With the recent California fires, I've been looking for a decent option. Unfortunately the Elgato Eve sensor is no longer sold, and the few other consumer products still hover in the $100+ range with poor reviews. PurpleAir sells an indoor sensor, but it appears to be limited release and somewhat 3D printed. https://www.purpleair.com/

The new version of the Eve Room sensor seems to be out: https://www.amazon.com/Elgato-10EAM9901-Generation-Technolog...

Re: Build a do-it-yourself home air purifier for about $25

#143

Important tip: if you set up an air purifier in your home, make sure to plug all drafts around your house: windows, doors, etc. Even a DIY purifier with small airflow can make your indoor air excellent if given enough time to do so and no leaks to fight against. If you want to get some fresh air in your home, do not leave a window half-open all day long—instead, open all your windows at once to cycle the air as fast…

Very interesting!

How does the Dylos 1100 Pro compare to, for example, the Nova SDS011 sensor? By my cursory review, the SDS011 is much cheaper and appears to offer a more native Raspberry Pi-compatibility experience.

Is the Dylos more precise? Can it produce readings the SDS011 can't? Are the two sensors measuring fundamentally different things?

Finally, if you had to do it all over again, would you choose a different sensor or stick with the Dylos?

Thanks for sharing your project and for your insights!

Re: Build a do-it-yourself home air purifier for about $25

#144
So I did this with a cheap $15 box fan and a MERV 13 filter. It performs very poorly, the filter impedes the airflow too much and the fan actually will intake most of the airflow from the front corners of the output side because it's less resistance. Axial flow fans only operate efficiently at low static pressures. This is why your home forced air system uses a centrifugal blower, which is more efficient at high static pressures.

tl;dr I'd use a MERV 11 or less on a cheap box fan. You aren't going to make a Class 100 clean room out of your house with this kind of setup.

Re: Build a do-it-yourself home air purifier for about $25

#145

Huh! I independently "invented" this myself a couple of days ago when the Camp Fire blanketed the bay area in smoke. I got a 20x20 filter and some duct tape from Home Depot and a box fan from Target. (After discovering that Home Depot only sells fans in the summer.) I don't think I was the only one, though. HD was doing a brisk trade in 20x20 filters, and I think I bought the last box fan at any Target in the entire…

When you can't get house parts, try auto and computer parts. Get some 120mm fans (or an array of 80mm, etc), and some engine air filters. Don't change the filters too often: "It is common, however, for servicing to occur when the filter appears dirty. Engine air filters are designed to actually increase their efficiency by using this initial layer of dust as an added filter layer. Initial filter efficiency is usually…

I did this a couple years back. 2x 120mm fans and a rolled up filter in between with a cardboard box as the frame. I never thought it could do much, but also never left it running very long.

I've been begging for a good use of old computer fans...

Re: Build a do-it-yourself home air purifier for about $25

#146
I worry about air pollution especially when I'm in Jakarta or Singapore so I bought the Dylos DC1700 air quality monitor. It is great to know exactly how bad the pollution is and how effective my air purifier is - I feel like I'm walking around with x-ray vision.

Re: Build a do-it-yourself home air purifier for about $25

#147

Generally there are two classes of objects that you want to filter for. Particulates and VOC (Volatile Organic Compounds). Think of particulates as specs of dust with varying size and VOC's as random chemical compounds such as spray paint, smoke, oders. The general go-to clean room/industrial filter stack is Prefilter(F5 Bag)->HEPA->Activated Carbon. The pre-filter catches all the big particulates to prevents cloggin…

> “The general go-to clean room/industrial filter stack is Prefilter(F5 Bag)->HEPA->Activated Carbon.” yup, i bought a blueair 211+ ( https://www.blueair.com/us/blue/blue-pure-211/1695.html ), that has exactly those filter elements in a nice (if bigger than expected) package. this model was recommended by both consumer reports and the wirecutter (until recently, cynically thinking they didn’t pay wirecutter’s “endors…

I have a pair of Vornados with the same setup. They're life-changers (no exaggeration).

Re: Build a do-it-yourself home air purifier for about $25

#148

I built my own air purifier in 2016, living in London, I was living in a basement and was having breathing problems due to mould. My landlady was gaslighting me at the time, so I built the air purifier. It worked for a while but mould spores cling to the paper filter and eventually grow into the filter material. I think Dyson uses glass fiber filter to stop this problem. My filter helped a lot, but eventually I had s…

Woah, this is pretty scary. Thank you for sharing. How did you know it was mold that was in the air? Is there some sort of test kit that you can buy to test for this. Mold is pretty hard to detect because you can't really see it because it typically hides between the walls. Any advice appreciated.

Mold needs lack of ventilation /dampness. You see the dark spots (maybe that's too late?) and IMO nothing substitutes air flow, when possible. Even in winter, one needs to open windows and let the air flow freely at least for a while.

Re: Build a do-it-yourself home air purifier for about $25

#149

Earlier quoted context omitted.

> health impact of its cheap plastics Do you mean the health impact of when the device is thrown away?

I think they mean of small plastic particles coming off the cheap device and polluting the air.

Never heard of this. Also, how would it differ from any cheap plastics coming off any cheap fan made partly or wholly out of plastic?

Re: Build a do-it-yourself home air purifier for about $25

#150

Generally there are two classes of objects that you want to filter for. Particulates and VOC (Volatile Organic Compounds). Think of particulates as specs of dust with varying size and VOC's as random chemical compounds such as spray paint, smoke, oders. The general go-to clean room/industrial filter stack is Prefilter(F5 Bag)->HEPA->Activated Carbon. The pre-filter catches all the big particulates to prevents cloggin…

> “The general go-to clean room/industrial filter stack is Prefilter(F5 Bag)->HEPA->Activated Carbon.” yup, i bought a blueair 211+ ( https://www.blueair.com/us/blue/blue-pure-211/1695.html ), that has exactly those filter elements in a nice (if bigger than expected) package. this model was recommended by both consumer reports and the wirecutter (until recently, cynically thinking they didn’t pay wirecutter’s “endors…

I just bought the same model. What makes it so effective is that it has a filter on four large sides so it can process a large volume of air very quickly.
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