the air curtain won't work, in fact it would make it worse.
Moving air will INCREASE the loss of cold air in the fridge, not decrease it. That's why there are fans fitted to heaters, to increase the transfer of heat.
One possibility would be to divide the fridge compartment into sections with transparent inner doors covering access to each section. The idea would be to trap the cold air in each compartment. This would however probably be pretty fiddly and annoying. I used to be quite keen on the idea of a top opening fridge, I started to build one some years ago. It had a freezer chest and a fridge chest in one unit, the freezer was about a 300mm cube (one foot cube), the fridge was about 150 litres. It was to have six inches of polyurethane insulation all round, the freezer was the main refrigerated section with the fridge being cooled mainly by a lack of insulation between it and the freezer, and a very small evaporator carrying vapor back from the freezer evap to the compressor. I had some help designing it from a local fridge mechanic and I was going to get him to do the connections and gas it up, use a Danfoss BD low voltage DC compressor. I never got the project off the ground, as I had to build a house to put it in first, and I guess I am getting soft in my old age (middle age) I just want a front opening fridge and Idon't mind buying a couple of extra solar panels or using a whisker more gas to run it. I still have some of the bits but I don't think I will ever build it.
Chris.
