What are the Economics of Super Insulating a Walk-in Freezer?

Dave is the way to go.

 

This standard thickness is there because it keeps the unit operating at a minimum of 35 degrees inside. If there is not a significant temperature drop inside the unit, the refrigeration unit will not be able to reduce the air temperature enough to keep frost from forming on the products inside. In order to make the unit work more efficiently and reduce the overall cost to operate, the manufacturers build in enough insulation for the unit to operate at the minimum of 35 degrees inside. The problem you have is that the insulation is not adequate for the application. What you are experiencing is the higher operating temperature of the refrigeration unit that is trying to keep the inside of the freezer colder. The cost of the higher operating temp of the unit will probably offset the savings from the extra insulation costs. You will also experience higher energy consumption as the unit operates at a higher temperature. You need to either insulate the back wall and ceiling or insulate the unit on the inside. You are right in saying that there is no free lunch when it comes to energy efficiency.

 

A commercial freezer is a large, energy-intensive machine that can cost thousands of dollars to purchase and install. You need to make sure that the design will be able to accommodate your needs and keep up with your operations.

You should also consider the economics of super insulating a walk-in freezer. The amount of money you save by not having to purchase a large, expensive machine is probably outweighed by the cost of purchasing a new one.