That old school simpler design you refer to has its own problems, relying on a fixed ratio of cooling where you often get either a warm freezer or cold fridge.

That old school simpler design you refer to has its own problems, relying on a fixed ratio of cooling where you often get either a warm freezer or cold fridge. See https://www.youtube.com/watch?v=8PTjPzw9VhY https://www.youtube.com/watch?v=8PTjPzw9VhY Modern fridge/freezer combos want to control the ratio of cooling. This is often done as simply as controlling a fan that moves cold air between the compartments.