I had many of the same questions when I installed a Residential fridge but I'm sure you probably have a much larger area to work with. I installed a 10.3 cf Haier(much larger than what I had for my absorption refer)...it was a perfect fit for me though. First thing I did was insulate the entire compartment with rigid foam board, I installed bilge exhaust fans behind the fridge, I did anchor the fridge frame to the floor, initially I sealed the rear vent, I put a side vent and vent under the floor of the new fridge to allow conditioned air to enter into the compartment. During travel, I use straps to keep the doors from flying open and to secure the fridge from tilting/moving. I also placed a temp probe in the compartment so I could tract the temp.
OK...so the results......I keep my eye on the temps and when needed use the exhaust fans, during extremely hot weather(100+), I will sometimes place a fan in front of the vent under the fridge to expedite cooler operating temp's(it works quite well). I partially opened the rear vent, which also seems to support cooler operating temp's. I didn't need to seal around the top, bottom or sides...it fit with no modification.
Anyways...all in all, I'm extremely Happy with the extra room and the cooling ability. The unit cools and freezes quickly and in 8 months of part time use, it's been great. Couple that with the 400.00 dollar price tag opposed to 1200-1500-00 for heat absorption refrig....what can I say. Hope that helps, I'm sure others will have plenty of suggestions.
