Hawkeye0001
Member
Sooo, I did something... silly and unneccessary?
Many years ago, long before the Sys Air came out, I wanted to build an air scrubber because I wasn't happy with what was available on the market back then. Unfortunately a T-Loc systainer was just about 5mm shy of enough internal width to accomodate standard 287 x 287mm HVAC filter elements and for the life of it I couldn't figure out how to cram all the components into a small enough package to make it work. I eventually settled for two Record Power AC 400 units that have done an okayish job since then and forgot about the whole idea all together (bar a lonely pocket filter in the basement).
Fast forward to a few months ago when I took some measurements for a Sys³ insert I wanted to make and lo and behold those ribs (in the bulges to the left and right of the pull handle) are gone with the 3rd gen and the internal width is now... 287mm! That's when I had a sudden lightbulb moment and ran to the basement to get this old filter element I had lying around - and would you believe it? It's an absolutely snug fit all around - as in: sealed! And the icing on the cake: the bulges now also offer the exact space needed to fit a standard 25mm and 48mm frame element back to back! I don't know if Festool ever intended to do something with that or if it's just part of a larger conspiracy, but I was majorly chuffed with my discovery!
So I went on a months long deep dive into HVAC theory, different fan types, interpreting fan curves, and electronics and ran a bunch of tests. I eventually found a guy on Ebay who sold a huge stack of ultra low profile 210W EBM Papst 225mm backward curved (important!) radial impellers for pennies to the dollar (like: 25€ instead of 170€ a pop) and boy, do they move air!!! I also managed to source a local company that produces ultra compact F9 pocket filters with only 200mm depth and that was the breakthrough to make it all come together; finally I managed to shrink the form factor far enough to make a M-size systainer feasible.
So it was tinker time! I picked up a used Sys 437, build a frame from 2020 and 2040 T-type aluminium extrusion to create the filter chamber and hold the impeller inlet ring, built the seperator wall and lid from 6mm Aluminium Dibond composite sheet (with some camper van pull-locks I had left over) and repurposed a 250mm x 100mm Sys Org inset box for the electronics bay. Add some EDPM foam tape for any air gaps and some spray paint for looks et voilà! It's a silly ADHD hyperfocus pipe dream come to live!
Would it have been faster to purchase a Sys Air? Yep, absolutely! By about 3 months R&D - minus the shipping...
Was it fun? You bet!
Does it perform? Yep, I can conveniently place my newspaper against the inlet grill while I sip my coffee, meanwhile the outlet side is enough to dry your hair after a shower. I added some sealant strips to the extrusion grooves and now it's also surprisingly quiet.
Total cost for the unit came to about 240€ (which conincidentally is about 20€ less than just the replacement filter set for the Sys Air), the filter system consists of a pleated 48mm G4 filter (9€) and a 200mm F9 pocket filter (12€). While the overall filter surface is admittedly less than the sys air for what they cost I can replace both filters 12 times over for the same money, so I'd say that is not too shabby.
Many years ago, long before the Sys Air came out, I wanted to build an air scrubber because I wasn't happy with what was available on the market back then. Unfortunately a T-Loc systainer was just about 5mm shy of enough internal width to accomodate standard 287 x 287mm HVAC filter elements and for the life of it I couldn't figure out how to cram all the components into a small enough package to make it work. I eventually settled for two Record Power AC 400 units that have done an okayish job since then and forgot about the whole idea all together (bar a lonely pocket filter in the basement).
Fast forward to a few months ago when I took some measurements for a Sys³ insert I wanted to make and lo and behold those ribs (in the bulges to the left and right of the pull handle) are gone with the 3rd gen and the internal width is now... 287mm! That's when I had a sudden lightbulb moment and ran to the basement to get this old filter element I had lying around - and would you believe it? It's an absolutely snug fit all around - as in: sealed! And the icing on the cake: the bulges now also offer the exact space needed to fit a standard 25mm and 48mm frame element back to back! I don't know if Festool ever intended to do something with that or if it's just part of a larger conspiracy, but I was majorly chuffed with my discovery!
So I went on a months long deep dive into HVAC theory, different fan types, interpreting fan curves, and electronics and ran a bunch of tests. I eventually found a guy on Ebay who sold a huge stack of ultra low profile 210W EBM Papst 225mm backward curved (important!) radial impellers for pennies to the dollar (like: 25€ instead of 170€ a pop) and boy, do they move air!!! I also managed to source a local company that produces ultra compact F9 pocket filters with only 200mm depth and that was the breakthrough to make it all come together; finally I managed to shrink the form factor far enough to make a M-size systainer feasible.
So it was tinker time! I picked up a used Sys 437, build a frame from 2020 and 2040 T-type aluminium extrusion to create the filter chamber and hold the impeller inlet ring, built the seperator wall and lid from 6mm Aluminium Dibond composite sheet (with some camper van pull-locks I had left over) and repurposed a 250mm x 100mm Sys Org inset box for the electronics bay. Add some EDPM foam tape for any air gaps and some spray paint for looks et voilà! It's a silly ADHD hyperfocus pipe dream come to live!
Would it have been faster to purchase a Sys Air? Yep, absolutely! By about 3 months R&D - minus the shipping...
Was it fun? You bet!
Does it perform? Yep, I can conveniently place my newspaper against the inlet grill while I sip my coffee, meanwhile the outlet side is enough to dry your hair after a shower. I added some sealant strips to the extrusion grooves and now it's also surprisingly quiet.
Total cost for the unit came to about 240€ (which conincidentally is about 20€ less than just the replacement filter set for the Sys Air), the filter system consists of a pleated 48mm G4 filter (9€) and a 200mm F9 pocket filter (12€). While the overall filter surface is admittedly less than the sys air for what they cost I can replace both filters 12 times over for the same money, so I'd say that is not too shabby.
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