squidgygoanna Posted April 24, 2017 (edited) Hey guys, I'm constructing a gourmet mushroom grow chamber/incubation area/lab inside 2 x 20ft insulated shipping containers. I've been working on figuring out my ventilation, air intake, etc and decided the best way to go would be to make a HEPA filtered air mixing box that my fan can suck air through. The filter side of the box will be attached to the side of the container and draw in fresh air from outside the grow room. The box also has a "hinged damper" on the bottom of the box, the position of which can be adjusted and locked into place to get the required mix of fresh and recirculated air. The damper can be either: completely open (allowing only fresh, filtered air to be drawn into the grow room from outside) partially closed (which draws in both fresh air from outside and recirculated air from within the grow chamber) or fully closed (damper covers the HEPA filter, blocking off fresh air intake and recirculating the air within the grow chamber only. I got this idea from one of Stamet's books and decided to have a go at building one. I've made it so the filter is removable so it can be cleaned or replaced. Kind of hard to explain the concept in writing so I've attached some pics. Thought you guys might be interested. Completed box with filter inserted Filter removed Inserting filter Filter end view Side view (holes are to lock hinged damper in place, adjusting the air mix ratio) Fan side, damper half open Filter side, damper half open Damper fully closed, blocking fresh air intake and recirculating air in grow room Edited April 24, 2017 by squidgygoanna 10 Share this post Link to post Share on other sites
SayN Posted April 25, 2017 looks good. one for each shipping container, or are you planning to join the containers? 1 Share this post Link to post Share on other sites
migraineur Posted April 25, 2017 Have you considered adding cheaper pre-filters to the design somewhere so that your expensive HEPA filters last a lot longer? Share this post Link to post Share on other sites
SayN Posted April 25, 2017 Have you considered adding cheaper pre-filters to the design somewhere so that your expensive HEPA filters last a lot longer? Sounds like a good idea, but i'm curious: if you do this, how do you actually know when the HEPA filter passes its use-by-date? Share this post Link to post Share on other sites
squidgygoanna Posted April 25, 2017 looks good. one for each shipping container, or are you planning to join the containers? One container will be used for fruiting, the other will be incubation with a small separate lab attached 1 Share this post Link to post Share on other sites
squidgygoanna Posted April 25, 2017 Have you considered adding cheaper pre-filters to the design somewhere so that your expensive HEPA filters last a lot longer? I was planning on adding a cheap pre-filter to the outside of the container, just something to stop larger debris 1 Share this post Link to post Share on other sites
migraineur Posted April 26, 2017 Look up furnace filters on Amazon. Filtrete makes awesome ones that I've used as pre-filters for my flowhood. Which edibles are you growing? Share this post Link to post Share on other sites
squidgygoanna Posted April 30, 2017 Look up furnace filters on Amazon. Filtrete makes awesome ones that I've used as pre-filters for my flowhood. Which edibles are you growing? Thanks mate I'll check them out. Starting with grey oysters and possibly shiitake. Would like to have a go at king oyster too. 1 Share this post Link to post Share on other sites
migraineur Posted May 5, 2017 Did you take a look at those furnace filters? What do you think? Share this post Link to post Share on other sites