1. How has that been tested? Or is it just theory?
2. Even in theory it doesn’t seem right: the (specific) heat capacity of air is extremely small compared to all foodstuffs and also compared to newspaper and Styrofoam. (Air also has a very low specific gravity.)
3. Practice. In order for a full fridge to pay off according to that ‘full’ reasoning, you have to insist on keeping it full. Every time you take something out of it, you have to put other things in it. But, you also have to search longer to find something and you also have to scrape longer to get the most out of it: old products have to be eaten first! You also have to take things out that need to be put back in. The time you need then also causes a lot of heating of the content and in my opinion is much worse than the air that is refreshed with a half-full!
The problem, of course, is how to measure something like that!
Eandis gives me the incredible answer that I could test it with a meter that can be rented for free. Either they don’t realize how complicated a science-based experiment is, or their noses bleed.
Perhaps there is an optimum value for every situation?
Answer
The problem is that every time you open the refrigerator you also pull out a piece of air. When closing, you push warm air back in. Thus, the specific heat capacity has little influence on the reasoning. People may search a little longer in a full fridge, but with some organization it’s not too bad I think (this is my own experience and not based on scientifically based experiments). In any case, the difference will mainly depend on how often and for how long the refrigerator is open. If it is mainly open for short periods, full is better. If they are often open for longer periods, it may be better not to overload them.
Alternatively, you can always do a few experiments yourself with an energy meter. Some home, garden and kitchen experiments do not always have to be 100% scientifically based to still yield useful results.
Answered by
ir. Joris Borms
Pleinlaan 2 1050 Ixelles
http://www.vub.ac.be/
.