Filter Your Air Intakes - Photos of < 2 Weeks of Buildup Will Convince You

Lately I've been seeing a lot of information out there about intakes without paying attention to filtering the intakes. No, not for smell; for the quality of air that your plants grow and live in. This is not something that you should overlook.

If you want proof: please continue reading. Before the pics though:

PLEASE FILTER YOUR AIR INTAKES

Growing indoors allows you to have an incredible control over the environment of your plants. This can be especially true for us micro growers. Especially those of us growing in a negative pressure environment (where your doors suck closed).

This part is important so pay attention:
When air enters a negative pressure environment, it will drop the heavier particles out of the stream of air as the air is moving from the intake to the exhaust. For most of us, the path from the intake to the exhaust is where our plants lie. Envision, if you will, a flock of birds, flying from your intake to your exhaust. Now, imagine all of those birds had a healthy dose of laxatives. Take that image and multiple it my hundreds of thousands, now millions. Wouldn't you like to do something to prevent that from happening to your plants? Especially delicate clones and seedlings?

I have read that you want air filters that are rated at least 1200 to catch all the nasties that could possibly hinder or even kill your plants. It's easy, cheap, and completely worth the peace of mind.

You can purchase a large sheet that is in the accordion-style with the metal meshing and cardboard frame. The metal meshing and frame come off easily enough, and you can cut pieces that will be suitable for your needs. Here's the one that I purchased:


Although there are other filtering mediums available for the intake, you want to be sure you're getting something that will be small enough to catch the mold spores and other small critters (and their eggs) which may cause harm to your lovelies. You should be sure that you have adequate ventilation to pull through these filters. I have a blower for my cabinet and it handles the filters without any problem. I cannot, however, speak for the ventilation setup of your situation so be smart and do a bit of investigation before you go slapping filters on your intakes. Please don't come back to this thread complaining that your cabinet temperature jumped since you added filters.

Even if you think your cabinet is in a clean environment, there are always factors that you cannot see which can (and probably will at some point) affect your growing experience.


Now then, with a happier face.

If that rant didn't convince you: it's time for the pictures.

I casually installed the air filters (thinking that it wouldn't really make an incredible impact) on my cabinet after it had gotten started and they were white and beautiful:


This was less than two weeks ago. Today, I went to take a closer photo of the intakes for another thread. As I got closer, I noticed there was a decent amount of buildup showing around the outside:


I removed the filter and it didn't look too bad...


...until I turned it over:


I'm no HVAC expert, so I can't tell you whether there's actually nasty stuff caught in there or if it's just dead skin cells. I can tell you, with confidence, that I'm glad that my plants weren't exposed to it so I could find out.

$15.00 for a sheet of air filter that will last you for months and some change for rubber bands...
...OR...
...take a closer look at what your plants will be exposed to in under two weeks:


If you haven't already, I would strongly urge you to consider filtering your intakes in your micro grow.

Just a little friendly advice to help you along in your travels.

-Q

Nice post Quazi... I know what builds up on the filters of my PC intakes and I'm 100% down with what you're saying. If you start with a sterile environment, and you control the quality of air coming into your cab, you are way ahead of the game in terms of mold/fungus/pests.

I knew I forgot something when I fired up the cab again. Thanks for the reminder.

Nice post... I need something like this.

This is a great idea. Yesterday I fired up my flower cab again and I sat inside of it with the doors shut playing with different fan speeds. When I put the exhaust fan on full speed both of my darkroom louvers started spitting all kinds of nasties into my cab. It was unbelievable.

Great post, thank you.

I filter my intakes with carbon impregnated pre-filter material, like what the odorsok thing is made with.

Keeps out pests and dust. Lots of dust. Every time I clean my filters I'm amazed at how much crap I've saved from getting caught up in the buds and carbon scrubbers.

But yeah, rarely ever a mention of filtering intakes. Deserves some emphasis, for sure.

Sweet idea!! I will get to work on my intakes ASAP!

Regardless of what material you use, I think it is important to understand how effective that material is at filtering.

Filter efficiency is usually measured by its ability to filter particles measured in microns. A micron is one thousandth of a millimeter. A human hair measures about 70 microns wide. Reference the following graph for the size of various contaminants.



Mold spores run between 1-30 microns, pollen 10-100 microns, spider mites 400-500 microns, and spider mite eggs 100-150 microns. The standard measurement used to measure filter efficiency is the Minimum Efficiency Reporting Value (MERV.)



Unless you are trying to filter out viruses and bacteria, then I don't think we need to be concerned with Microparticles that run 0.3-1.0 microns. A MERV of 12 seems to be what we want. If you are only concerned with insects then a MERV of 9 could be adequate. The better the filter is at capturing smaller particles, the more pressure will be needed to pull air through it. Therefore the better the filter, the stronger and noisier a fan you will need.

The Microparticle Performance Rating (MPR) is used by 3M to measure how well their filters perform in the 0.3-1.0 micron range.
1250 MPR = MERV 12
1000 MPR = MERV 11
600 MPR = MERV 8

Thanks Quazi. I enjoy your threads.

Glad everyone has found the thread useful.

If I can convince at least one person to filter their intakes then it was worth it.

I completely agree with what was said above. I read that at least 1200 is what you need to go with if you're really trying to keep the place clean of nasties.

-Q

I had this thought when i was designing my cab. The filters not only keep out dust, bedbugs, etc but also should help to keep out mites, pests, bugs.

I had further thought about it and it may be desirable to be able to keep out pollen too. So i was thinking back to my days as a mechanic, and early to mid 90s GM cars here in the UK had a pollen filter for the cabin blower/ac which was a flat element stretched out across the top of the bulkhead. Most modern cars now have a more engine air filter-esque accordion filter, which will be more difficult to work with.

So look for a vehicle pollen filter, one that is flat like a cooker hood filter. I got one from my local motor factor (carspares) for a few £ that will cut down and make me enough filters to last veg and flower cabs for several years - consider that these filters are designed to be replaced once a year in an environment that is a LOT dirtier than inside a typical house. I had thought about using carbon foam but it would be kinda wasteful for an intake.

Just an update on the intake filters.

I recently replaced the ones that you saw in the original post and you can see they caught quite a bit:


In fact, one on my veg side caught a gnat (which I found a couple of in my flowering chamber but not veg) making the intake filtering every bit worth while:


-Q

If you think about it a filter is a must. For the most part everyones intakes are on the ground and placed more towards the back of your cab/grow space. Dust and all sorts of nasty stuff can build up quickly behind just about anything let alone a cab with air sucking everything back there. Hopefully this will prove to people that spending the few extra dollars on filter is worth it. I know in the cab I built I had a 3m filter for the intake and then I used more in between each chamber, just in case. I've grown up with allergies though, so I may have an above average knowledge of what a difference clean air can make. I look at it this way: If I don't want to breath it in, I doubt my plants want to. Great example Quazi

-Also I found that vacuuming the room your cab is in can make a difference in how dirty your filter get as well.

i hardly think this stuff can get into or block the plants stomata. on the odd chance it gets something blocks it even a slight breeze will unlodge it.

No one said this was a good idea for pieces of dust that may block the stomata of your plant. What it is good for is all the other things that may introduce themselves to your plants such as mold, insect eggs, etc.

Besides, as you said:

on the odd chance it gets something blocks it

Click to expand...

I'd rather not have it occur in the first place.

-Q

I'd rather not have it occur in the first place.

-Q

Click to expand...

Yes, seconded. Thanks Quazi

I'll be ckecking in on that in the am.. thanks!

what filters the air outdoors?

stihgnobevoli said:

what filters the air outdoors?

Click to expand...

exactly