Hot Box Build w/pictures -- DIY


Cant Re-Member
Old Timer
Nov 1, 2006
hi everyone. sorry in advance for the lengthy thread here. just trying to be thorough and helpful.
total cost to build this not including the rack, hole saws, drill, etc will be about $150.
i have been reading about different ways that people keep inverts in quantity. i thought that i would share my way of doing it in hopes that it helps someone else. i have a few of these and they work great. they fit on a 48" wire shelving unit (45" inside length) perfectly. ill do my best to illustrate what i have done but bare with me on the fine details. i am open to any questions if you have any.

first you will want to ensure that you have a location that is able to handle a box of this size. if you have a rack, ensure that the shelving has a inside clearance of at least 45" wide and 18" tall at a minimum. anything less and this will not fit (unless you modify the size of the box prior to building it).

for the box shell, you can choose any type of wood you desire as long as it is 1/2" thick. anything thicker will increase the overall size and it will not fit on your rack.

you will need the following pieces:
--2x 17"x18"D (this is the sides of your box).
--2x 18"x44"L (this is the top and bottom).
--1x 44"x17"T (this is the back).
--2x 18"x22.5"W (these are the doors).

the wood i chose to use was from home depot and comes precut 24x48". i chose medium density fiberboard that cost $10 a sheet. i then ask home depot to cut these pieces to the above dimensions for me (they do it free). just ensure that they cut them accurately and allow for the saw blade thickness. i tell them I'm building a precision made box so accurate cuts are important to me. if i remember right, it tales 5 pieces of the 24x48 precut wood to get the pieces you need. you will have a lot of scrap left over. save it or throw it away...your choice.

you will also need one sheet of foam insulation board. this comes in 4'x8' sheets for like $10. i use the 1/2" thickness.

you will also need a few door hinges. i like the continuous hinges from home depot. they are 1-1/16"x12". you will need 1 for each door.

i would also highly encourage you to purchase a usb wired computer fan. i use coolerguys usb fan with grill from amazon for $11. this will circulate the air inside the box for a consistent, even temperature distribution.

i also recommend a thermostat. you can spend big bucks if you want but i use, and have lots of, the zilla 1000W thermostats. i also use 2 thermometers with probe for temps and humidity readings. i put one on each end.

8"-11" zip ties will help you a lot too. also some double sided 3m tape is very handy for cable management.

i get my led lights from amazon as well. you can get whatever brand or color you would like but i would recommend white/daylight. these lights come in a little box with 16' of light. just cut the length you need and stick it to the inside of your box. DONT FORGET to get the DC power supply cable for the light strip. the lights are $8 and the power cable is another $8.

i chose a power strip/surge protector that also had usb plugs. makes it a lot easier to get your computer fan plugged in.

you also need a 4 pack of 4" round plastic louver insect screen vents. these are amazon purchases as well and cost $11 for the 4 pack. i only use 1 on each side (at the top) of each box i build. fresh airflow is very important.

a 4" hole saw, drill, and a 1" hole saw will be needed as well.

you will need the appropriate screws. i use #6 1-5/8" interior wood screws. i would get a box of 50 or so. i get mine at Walmart.

also needed is a heat source. i use heat tape from reptile basics. i get a 4-5 foot section prewired and a roll of aluminum tape. pay the extra $1 and have them wire it for you...its worth it.

while you're at Walmart, grab some Loctite spray foam adhesive (maybe 2 cans), a cheap wall timer for your led lights, and a bulldog hardware 3.5" swivel hasp. door handles are up to you if you want those too.

so to build the box is pretty easy actually. just put the pieces together before you drill to ensure they line up and the correct piece overlaps the correct piece. for example.....your top and bottom pieces will go the full length of 45" and the sides will sit flush with the edges of the top and bottom. makes sense?

once you have figured out the positioning of the pieces, carefully screw them together being sure not to go in crooked or too close to either edge. i would recommend you drill pilot holes first but you can get away with not doing that if you are super careful. for the doors, i attach the hinge to the door first and then square up both doors before screwing the hinge to the box itself.

once the entire box i screwed together, measure the inside dimensions of the box, one side at a time. cut your foam board to fit snug against the walls. you want the metallic shiny side facing out and spray foam adhesive on the other side. also spray adhesive on the wall of the box, let it set for a minute, then stick the foam board on the wall and press firmly to get a good bond all around. do all sides.

the doors will require you to crawl half way inside the box, close one door, and use a marker to mark lines where the foam needs to go (this will be inset so the door will close flush). repeat on other door.

once the foam is in place, use dap or silicone to fill in any gaps or cracks. this helps insulate and prevents escapes. **personal preference...i spray paint over the silicone.**

once that is fully dry, i drill 4" holes for the vents, a 1 inch hole in the top right corner of the back and two 1/8" holes on both sides of the 1" hole. obviously the 4" holes are for your vents. the 1" hole on top will be for your fan cable, any other cable you need to poke through.

to mount the fan, I drill 2 small holes in the top corners of the fan and run a zip tie through and then through the smaller drilled holes on top. this will allow your fan to hang down from the top still allowing airflow on all sides.

get your heat tape mounted on the inside walls (I normally mount all the way across the back wall and any left over is either cut off or continued on one of the side walls. use your aluminum tape to secure it to the foam board. leave gaps in the tape every so often so heat doesn't build up behind the heat tape and cause an issue. I usually mount the heat tape in the middle of the box or slightly more towards the top of center.

place your thermostat probe inside and secure it to the top of the box, in the middle but away from the led light strip you may or may not choose to install.

**you will need to "play" with the thermostat to get the correct temps you desire and depending on the placement for the thermos/hygro probe, the readings may be different. I recommend a infrared laser temp gun to determine the actual temps inside of each invert enclosure within the hot box.

you can install a bit of weather stripping on the inside of one door. this way, when you close both doors it, more or less, seals the door gap preventing escape and heat loss.

install your 3.5" swivel hasp (or any other form of hardware you can come up with that will secure the doors shut in a good tight manner with some tension). I use the larger part of the hasp on top of the hot box so the lever hangs down. on ONE of the doors, I place the locking twist hasp so that it covers both doors. you may have to install it in a diamond pattern rather than a square pattern to ensure it holds the other door shut when locked.

next you can either paint or stain the exterior of the box. that's up to you. if you paint or stain, ensure it is fully dry before you place any inverts in or around it. I chose flat black spray paint that was fully dry within 24 hours.

following these plans will create a little micro climate that you can control down to the half a degree. the heat tape will get REALLY hot in a insulated box so a thermostat is a must have!! for can go from 70F to 95F in about 3 minutes so please pay attention.

I hope this helps some of you. if you have any questions, I would be more than happy to hear from you. ENJOY!!!!

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Old Timer
Dec 8, 2006
What's in the black box? What's growing on the bottom shelf w/the lamps?

Much appreciated the details! More details are better than fewer.;)

@Ceymann might be interested?