Flue chamber/Kiln conversion

[Berserkjibis]

I have a 4x4 insulated room in my garage. It was used in the past to grow medical plants, and now it's just sitting there dormant. I'm looking at trying to convert it into a flue/kiln and need some pointers on what I need to do to make it be able to withstand the heat up to 165°f if that will be possible. It's built with 2x4's with r-13 insulation. For the walls I used 1/2 drywall with the exception of the ceiling and floor. The ceiling and floor are 3/4in subfloor. The floor has linoleum stick on flooring, and the top is just painted white. There are 2 electrical outlets in there ran through the drywall. The door is just a standard interior hollowcore wood door that I could replace if I need to. I have inkbird temperature and humidity controllers in there that I could mount outside of the room if needed. Does this sound like something that could be easily converted or would I need to do a major overhaul? Thanks

 

[deluxestogie]

would I need to do a major overhaul?

I would say, major overhaul. The kiln will experience continual, very high humidity, with cooler areas (like circuit boxes) attracting significant condensation. Drywall won't be for very long, since humidity will promptly saturate it. Any electrical fixtures and connections need to be appropriate for a humid or damp environment. (e.g. a bathroom exhaust fan) All joints and closures will need to be vapor-sealed. The hollow-core door would likely become a site for mold as well. For flue-curing, the temp of the space needs to be capable of sustaining 165°F. The larger the space, and poorer the seal, the higher the energy costs. I would suggest building a purpose-built kiln/flue-cure chamber.

These are just my thoughts.

Bob

 

[Oldfella]

And then there's the Linoleum. It has to go and removing all the glue sounds impossible. Build a new one.
Oldfella

 

[Berserkjibis]

I would say, major overhaul. The kiln will experience continual, very high humidity, with cooler areas (like circuit boxes) attracting significant condensation. Drywall won't be for very long, since humidity will promptly saturate it. Any electrical fixtures and connections need to be appropriate for a humid or damp environment. (e.g. a bathroom exhaust fan) All joints and closures will need to be vapor-sealed. The hollow-core door would likely become a site for mold as well. For flue-curing, the temp of the space needs to be capable of sustaining 165°F. The larger the space, and poorer the seal, the higher the energy costs. I would suggest building a purpose-built kiln/flue-cure chamber.

These are just my thoughts.

Bob

Thank you for your response!

 

[Berserkjibis]

And then there's the Linoleum. It has to go and removing all the glue sounds impossible. Build a new one.
Oldfella

Yep, that I'll do! Thanks for your input

 

[LeftyRighty]

I agree with Bob, but you have a closet space that you could build a kiln inside. - but will require lots of work.
This is what I'd do, if I really wanted to use this space.

First, use only GFCI electrical outlets, switches, lights, fans, heaters, etc, preferably 20 amp circuit with 12 gauge wiring. It would be worth the cost to have an electrician install a 20 amp circuit box. To get to 165 deg in that large space, it'll take at least 2 large crockpots or a ceramic heater. Preferably any switches, outlets be installed outside the space.

You will get lots of condensation, whither using as a kiln or flue-curing, you'll need a floor drain. Suggest that add wood framing around perimeter of space, add exterior grade plywood floor, heavy weight in center of space so floor slopes to a drain, nail all down, install drain with pipe to outside, or hose to drain in garage.

The existing wood framing & drywall will quickly degrade in the hot/wet kiln, so it must be protected (or rebuilt). Thus, paint every inside surface with waterproofing exterior primer paint, and seal all joints, edges, cracks with high-temp silicon caulking. I would install a plastic sheeting vapor barrier, using waterproof glue (or silicon caulking), sealing all joints.

If you want more insulation, glue 1 or 2-inch foam insulation to walls/ceiling. Then cover all walls with exterior grade plywood; need something solid to attach shelves, brackets, hooks, whatever, for hanging or stacking tobacco to kiln or flue-cure. Paint it with exterior-grade paint.

Now, the Door. The only door that won't warp would be a steel door, or maybe an old refrigerator door.
But, to use the existing door, add exterior-grade plywood to inside face of door, thoroughly paint & seal all. The door stops on the frame will need to be moved or rebuilt, adding refrigerator-door-style seal strip all around.
The door will eventually warp some, so, I'd gerry-rig some sort clamping system around the door edges to hold it snug against the seal.

Now, for temp, humidity, ventilation, etc. First, wire a master-switch so all can be turned off during the off season.

For temperature control, I have used a Ranco ETC-111000 for about a decade, never any problems. Wire the Ranco to the crockpot or heater outlets. Crockpot cords are too short, so place outlets very near by. I installed 1 1/2 inch PVC pipe thru thru the wall, sealed with silicon caulk, ran crockpot wire thru to outlet, stuff foam rubber around cord in the pipe.

Wire an interior light with outside switch. Wire a few small fans for continuous operation. I,ve used small computer fans, does not take much to keep air moving.

For ventilation and RH control, normal convection currents work great (hot air rising). For fresh-air intake, use 3 or 4-inch PVC pipe thru wall near floor, with wire screen cover for insect/rodent control.
For exhaust, a 1 to 1 1/4-inch PVC pipe thru the wall near top of the space will be adequate. Add a ball valve to control humidity. Add hose also to drain. Doesn't seem like much but it's amazing how little it takes to work well.

so, this is what I'd do with your space.