Is there general guidance on how much tubing to cubic feet? What diameter tubing and length? It looks like he just put tubing on the freezer side and maybe put some sort of spillover into the fridge side.
This seems like this is sort of an ideal solution - you never have to worry about puncturing and evaporator and you don't lose the space to an evaporator standoff.
Also, it seems like if you are running copper tubing against stainless sheet there is some potential for galvanic corrosion
. I suppose you could use copper sheeting instead of stainless.[/QUOTE
As to the size of evaporator tubing it is the compressor's refrigerant return line size that determines evaporator coil. It compressor is a Danfoss BD model 1/4 inch OD copper tubing is recommended 25 to 35 feet in length.
I have had to repair three of this type evaporators hidden behind stainless liners. Still do not know why they failed but my fix was taking a fifty foot roll of refrigerant and cutting it in half without unrolling it. I then clamped the half roll as is using screws to either one wall or to the top of box.
Soldering copper to stainless is not easy and this length of evaporator I would not try. Cleave at SeaFrost and Rob at Frigoboat USA both use stainless steel
to cover and protect copper evaporator coils they may be able to advise you on tubing behind stainless liners.
Ice makers cabinets use an aluminum
heat conducting past between evaporator and ice maker that might be a solution for a behind the liner evaporator.
Home Depot also has a super aluminum heating
and AC tape that might be the best solution, it is strong and seems to hold forever.