Combat Mold Issues With HEPA: The Inexpensive DIY Solution

Douglas.Curtis

Autistic Diplomat in Training
Why HEPA?

HEPA filtration is the number one defense against molds and fungal issues with cannabis. Harvest molding while it dries? Trimmed flowers molding in your jars? Packed a bunch of cannabis away, and come back to find it's ruined with mold? In a well ventilated flowering room (3 complete exchanges of air per minute), over the 2-3 month cycle, the trichomes of your plants can pick up an amazing number of mold spores.

When moisture levels and temperatures levels are high enough, those mold spores will cause enough mold to ruin a harvest in only a few days.

HEPA filtration stops fungal spores, stray pollen, bear and beaver dander, feces dust from all kinds of animals, pet hair, human hair, carpet and clothing fibers, bugs and more.Once you've smoked HEPA grown cannabis for a while, everything else starts feeling harsh in comparison.

HEPA filters are so cheap to build, everyone with DIY skills should be using them. I recently built one for the LED cab I'm building, and figured everyone here could benefit from a separate thread.

Here's the completed filter, attached to a fan.


The 'Plenum' before installing the filter. This can be as simple as 1x4 and thin plywood, screwed together and sealed with caulking. With larger sized filters, you'll want to cut multiple square holes, leaving cross braces. This filter size '14x20' will filter up to an 8" fan, and a 25x25 filter will work for 10-12" fans.

Drywall channel for corners is used to create a frame for the filter. The frame is secured and sealed to the plenum, and the filter is taped into the frame. When the filter needs to be replaced, simply cut the tape and exchange dirty with new, then re-tape.

The drywall corner channeling cut, bent and sealed to the plenum.


Closeup of a cut, secured and sealed corner.


The HEPA filters I typically use.


Filter installed to plenum, and is now all taped up and ready to go.


Hope a great many of you try this and enjoy it. I've been doing it for 15+ years and love the difference. Be good to yourselves.
 

THC123

Active member
Excellent thread!!! Professional ops always use Hepa filtration but it is very nice to see a affordable version for the homegrower!
 

I'mback

Comfortably numb!
Both my veg & bloom tents have passive intakes via a HEPA filter. I have been doing it since day one :)
 

Bobby Boucher

Active member
I've taken to putting carbon pads over the hepa filter to help keep house smells out of the intakes.

In the dry box intake, it goes carbon/hepa/carbon/damp wicking filter.

The water in the wicking filter still picks up a lot of crap!
 

Douglas.Curtis

Autistic Diplomat in Training
Carbon is one I've considered a few times. I've taken a half-toke of fabric-softener cannabis before. Gack. Tents are not something you want in a fabric-softener laundry room. lol
 

Chunkypigs

U can tell by the smell I'm living near the creek
wood is a poor choice for plenum making, going to grab then release the things you are trying to eliminate..

there are cheap solutions for high MERV filters.

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and less cheap but properly engineered.

fam1165_1.jpg


https://www.hvacquick.com/products/...CQuick-CFB-Series-MERV-13-Inline-Filter-Boxes

once you get the particles filtered from the air UVC is the best way to kill molds and viruses and if you don't include some type of photocatalytic uvc in your system downstream from your filter you are missing the boat.

81IqX5FbYyL._AC_SX355_.jpg



https://www.amazon.com/D200-PCO-photocatalytic-Conditioning-Germicidal/dp/B0754C889Z

this is a $90 model you can grab at Amazon, I have one, but I built a more powerful one with 2 36watt bulbs using replacement screens from commercial filters.

picture.php


my unit starts with a big carbon filter then fan then MERV then UVC and runs 24/7 scrubbing the sealed room.


this is a fancy weed model unit

AirSniper.jpg
 

Douglas.Curtis

Autistic Diplomat in Training
Cute. ;) As for wood, I'm not building microchips so it's ok. Appreciate the suggestions for when I have a budget. :)
 

Mars Hydro Led

Grow on Earth Grow with Mars
Vendor
Great idea. Douglas. :tiphat:

The mask pictures about wuhan are funny. Lol. But we never see that from news. Maybe they are made by PS.
 

Douglas.Curtis

Autistic Diplomat in Training
Great idea. Douglas. :tiphat:

The mask pictures about wuhan are funny. Lol. But we never see that from news. Maybe they are made by PS.
It's some scary stuff, and I definitely wouldn't want to be there right now. If I had a weaker lung or immune function and no budget, I'd most likely be doing similar things. lol You know my room would be hepa filtered, probably triple filtered. :)

More than a few times, people have called me crazy for years over one thing or another, only to apologize later when the truth becomes fully known.

Lots of reasons to build yourself a workhorse HEPA, with replaceable filters. :)
 

Mars Hydro Led

Grow on Earth Grow with Mars
Vendor
It's some scary stuff, and I definitely wouldn't want to be there right now. If I had a weaker lung or immune function and no budget, I'd most likely be doing similar things. lol You know my room would be hepa filtered, probably triple filtered. :)

More than a few times, people have called me crazy for years over one thing or another, only to apologize later when the truth becomes fully known.

Lots of reasons to build yourself a workhorse HEPA, with replaceable filters. :)

Yeah, we wear mask everyday to keep safe.

crazy people can always reach some crazy goal. I think it is not a bad word. lol. We will wait for your crazy harvest. :biggrin:
 

teide

Well-known member
could one diy hepa filter contraption be placed separately in the room where my cabinet is, filtering some of the ambient air before it enters the passive intake, or would that be redundant/ineffective?
I bet it would be better to have it inside the stealth cab or having the very intake being a filter, but my stealth setup doesn't allow that. A separate filter box just cleaning the ambient air in the room I could explain, but some filter attached to my specific intake would give it away..
 

f-e

Well-known member
It's so bloody expensive. We had a carpet roll of the stuff when I worked at an R&D center for respiratory medicine. The blue&white one sometimes seen in hoovers, or sewn into bag filters. But no... I don't take from work
 

flylowgethigh

grassyhopper
ICMag Supporter
ICMag Donor
20x20 room box fan with a 20x20 filter duct-taped on one side, to clean air inside the room already? House? Idea just popped in, sorry.
 
Here's how I was doing it.

picture.php


Just tape it up and tape the open end to the intake tube. Works pretty good. Check tape periodically.
 

Douglas.Curtis

Autistic Diplomat in Training
Yes, running a fan/filter combo in the room will help clean the air. It'll definitely work better than no filtering. :)

The filter material is crazy expensive, yeah. A 14x20 from Wallyworld (3m ultra-allergy) is $20. Fortunately, the larger filters are only a few dollars more, so nice for cutting up and using with smaller filters. :)
 

flylowgethigh

grassyhopper
ICMag Supporter
ICMag Donor
I see you have 1500 filters. There are finer ones... 1900, and higher. Lowes, Home Depot. I use 1900 in the house cause the dawgs and I track in a lot of dirt, mold.
 

Douglas.Curtis

Autistic Diplomat in Training
I see you have 1500 filters. There are finer ones... 1900, and higher. Lowes, Home Depot. I use 1900 in the house cause the dawgs and I track in a lot of dirt, mold.
You're quite correct. :)

I've always used the 1500 - 1700 filters from 3M as they're the least expensive anti-pollen filter I know works. My main concern is the pollen, which the 1500's are fine enough to stop. Though I've used them for 15 years without issues, the only reason I still don't buy the 1900's are because of budget. lol So lame. :)
 
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