I never did calculation of refrigeration cabinet, but what I use for fast calculation, for esthetic wine cellar which a mainly made of glass wall and of different size (buffet size too small wardrobe), I use the cold room of coolselector software from danfoss, and I choose custom panel. Then I fill the info with thickness and the conductivity of the glass wall selected by the designer, and it fits. You will have the option of goods, lights, fans, defrost ..