Getting ready to start big fermentation chamber

I'm getting ready to start a big ferm chamber and have a few questions from those who have built them.
It will be 72" high, 48" wide and 24" deep. Two plastic conicals in the top space and ample room for buckets and bottle conditioning.
My questions.
What material should I line the inside with. I'd like to be able to clean it out easily. I was thinking maybe the pvc sheets you can get from the hardware store. I haven't seem them lately, but remember guys used to put them on their skateboard ramps when I was younger.
Should I put the a/c unit on the top or the bottom of the chamber?
Has anyone put a viewing window on theirs? I was thinking of a double layer of plexiglass in the doors.
Do I need air circulation in the chamber? I've got an extra brand new bathroom vent fan I can place in it.

What are you using for insulation? The rigid foam insulation that I used to line mine wipes down pretty easily. The plastic sheets (like used to line shower stalls) would work well if you don't mind spending the money on them.

The location of the AC unit is mostly personal choice, I'm not sure if it makes a big difference.

You will probably want something to recirculate the air inside the chamber to keep it from developing temperature stratification (especially a chamber that tall). Most people use computer case fans since they are cheap and very light weight. They are also easy to wire to a plug if they don't come with one.

Open cell in 4x10' sheets. 1.5" thick. I've used it to isolate the heating/cooling in a two a/c unit home before (made a false wall) and it worked great. And it's the best price...freeeeeeee.

Yeah, you'll definitely want to cover that with something. You could do a thin plywood cover and seal it well, or you could use the plastic FRP board and caulk the corners. It will add a little cost, but since you got the insulation for freeeeeeeee...

Is FRB board the stuff they line cheap showers out of? That was my other choice. What do you guys do for mold/moisture prevention? Is air circulation enough?

Yeah, thats the FRP board (I'm pretty sure).

HD/Lowes should sell it. Should go on with construction adhesive and seal in the corners with caulk just fine.

I haven't had any issues with moisture buildup, even with 4 fermentation's going on at once in my chamber. I've got a small computer fan that turns on when the compressor does to circulate the air and cool the chamber faster, but it turns off when the compressor does.

IF you're worried about moisture, they sell these rechargeable dehumidifiers on amazon that members here seem to love for their keezers. Do a search and you should find them.

I just built one similar last winter. Not as tall but its still decent size. I used 2x4's and rigid foam and the capped it all with plywood.

Very nice! That's similar to what I'm thinking, but half the height. I'm not putting mine on casters either.

I'm going to do the fan with pvc ducting (as I have both already) wired to stc1000 with the fans running whenever the cooler or heat is on. I'm going to try and build in such a way that I can make it a two chamber without too much trouble in the future.

Now I just need a chance to go purchase some lumber.

I wish I had the mad computer skills to make one of those cool models for you guys, but my graphic design ability is limited to crayons and napkins.

Between 2' and 3.5" of rigid foam insulation all around. 2" on the sides, back and front, and 3.5" on top and bottom.

2 always hot outlets, 2 controlled heating outlets, 2 controlled cooling outlets. STC-1000 controller off Ebay.