This project attempts to address a number of challenges that commercial products have a hard time resolving.
Security: tents aren’t lockable, which makes it harder to grow responsibly and safely in one. Commercially available grow boxes all seem overpriced, and few are more discreet than a tent.
IPM: unless the manufacturer applies a sealant to every seam, tent’s really won’t keep out persistent pests.
Modular Design: I don’t expect any version to be perfect, and I want to be able to modify/swap out components with reasonable ease.
I took some inspiration from theatrical flats; these lightweight walls come together and store compact when apart. These panels are 3/4" plywood strips glued to 1/4" marine plywood (painted flat white). Corners are butted together and sealed with a generous bead of black caulk before being screwed with 2" self-drilling construction screws. Each chamber has a “picture frame” flange top and bottom. These get sealed with black sealant, and screwed together. They also create a sturdy mounting point for hardware. The bottom of the crate is a torsion box, which would be overkill but could prove critical if there’s a heavy reservoir or 4 DWC buckets.
The first iteration was about 4’6". There were (2) 24"x24" connected chambers, and a top and bottom. It would work fine enough, but with a heater and humidifier on the bottom the plants would be crowded. It would be acceptable for hand-watered soil pots, but not ideal.
Note: The top is shown hinged up for clarity, but it isn’t meant to be hinged. It can be unscrewed if necessary.
A hinged door allows secure access to the plants. It’s sealed with an epdm foam door weatherstrip, and has a lock.
Electrical: There would be a PVC outlet box mounted in the upper section, containing two 15amp duplex outlets. PVC conduit would run from the box through a panel wall, sealed with fittings and sealant on both sides. The plug tail coming out of that would be firmly secured and sealed to the conduit fitting.
Ventilation: The air intake is a passive 4"x4" HEPA filter mounted in a light trap on the door. The exhaust fan would be a 4" AC Infinity Raxial inline model ducted to a 4" Vanleno carbon filter.
Heating: 1000watt electric forced air heater for New England winters.
Lighting: I’m gonna talk a lot about lighting eventually, but an HLG 100 4k or 3k would perform well. An HLG 135 R-spec would be superb. I’m strongly considering either a Mars TSW 2000 or a FC3000.
Misc Equipment: Various InkBird humidistat and thermostats, a 4" clip-on fan for circulation, a small humidifier, and a mechanical timer for light control.
Revision 1: An additional 20" tall section will be added below the plants to accommodate an electric heater, a humidifier, as well as two reservoirs (one for inflow and one for runoff). The access panel for the lower section will be unlocked, but light-tight. I changed the electrical plan to use a number (2-3) weatherproof outdoor power inlets (available for about $15/per) instead of the earlier conduit solution. It’ll make cable management easier, and should actually be less expensive. I’m also considering a comprehensive environmental controller like the AutoPilot Eclipse F60. The F90 is also in contention, but it’s only necessary if paired with a light like the TSW 2000 or FC3000, where elevated CO2 would actually be useful.
Shown with 5 gallon buckets for scale.
Questions and comments are welcome.