My family moved our bakery into a building about 10 years ago that had a room that HAD been a 11' x 11' freezer with 8" urethane foam in all the walls and floor but the previous tenets pulled the evaporator and door and used it for storage.
So when we moved in I installed a new condenser and unit cooler and had a local company install a door and its worked great. But now we are at the point of needed a large amount of freezer space but there is no place outside the building to installed a "knock together" unit.
So the plan is to take the store room next to it and turn it into the cooler and turn the room that is currently the cooler back to a freezer as it was originally.
My plan is to put up a thick 8-10 mil rubber vapor barrier over the walls and ceiling. Then build walls that are 8" thick with staggered stud construction and have the local spray foam (the two part stuff) spray R-30s worth of foam in the walls and cap them with plywood and FRP over that for health code. For the ceiling I was thinking about about 4-6" of foamular styrene paneling and cover it with plywood and FRP also.
For the door I'm going to see if I can get the local company that did the last door to put the one that's on the cooler now on the new cooler and sell me a heated freezer door to put on what will be the freezer.
My questions are mainly about the construction methods. Is there anything I'm overlooking as far as the vapor barrier and insulation method?
I already have a 1hp beacon II R-404 semi-hermetic unit on the cooler that will go on the store room/new cooler that's also 11' x 11' and I'm going to put a 2hp semi-hermetic R-404 beacon II unit on the freezer. Its rated for 9,500 BTUH for -20F SST with the unit cooler rated for 9,500 BTUH with a 10 deg TD.
I know I sound kinda DIY with this post but I went to UTI here in Houston here for HVAC and have had my contracts license with TDLR since 2002 and still carrying insurance. Its just 8 years ago I developed lupus and couldn't deal with the physical demands of HVAC work. So I went back to school and now I teach high school science. The only reason I'm tackling this project is its the parent's bakery and its kinda hard to tell the parents no. It's just after 8 years I'm wanting to make sure I'm not overlooking something that will bite me in the rear later.
So is there anything I'm overlooking with the construction aspect of the room?