This looks like the best place to get answers on a few subtle questions that I haven't seen addressed elsewhere:
I've purchased a 10'X12' pre-fab shed as a reptile room. It's a white pine 2X4 (mostly) frame with aluminum siding and pressure treated floor (plywood over 2X6's).
I live in south Florida, so it's far more important to keep heat out during the summer than in during the winter. I will be puting in a small window air conditioner. I will be shooting for somewhere around
75-80 degrees F during the summer.I will have 3 1/2" of space I can insulate in the walls and more in the ceiling. Is 3 1/2" fiberglass insulation (R-13) the best I can do here? I think I gather that using thicker insulation and packing it in will be worse rather than better, but is there a better insulation I can use? Everything else I've looked at seems to have a lower R value for the same thickness.
Given that the siding is aluminum, would it make any difference to put that reflective foil between the siding and the insulation, our would that only help with a wood surface? How about between the insulation and the wood panneling on the inside?
The shed is on blocks rather than a slab (maybe 6-8 inches above ground). Would I gain anything by insulating under the floor or would I be better off letting heat from inside radiate to the ground below, which will be cooler than the air outside? Will it just be unworkable to have fiberglass exposed undernieth holding in moisture (entirely aside from the issue of animals nesting in it)? Would I gain more by putting some sort of skirt around the perrimeter to keep hot air from blowing under the floor?
I got the shed in all white to minimize heat absorbtion. Would it matter much if I painted the roof with reflective silver roofing paint?
Anything else I haven't thought of?
Yes, I realize I may be going overboard, but anythything that reduces the load on the AC and gives me more time before the room becomes an oven if the power or the AC fails during the summer is probably worth doing.
Also, any suggestions on how I could treat the white pine frame, in place, to keep termites and such out that would not be toxic to reptiles? Yes, I know the second part is pretty far afield for this group, but I thought I'd ask...