waste of refrigeration

[benncool]

What you hear running are the evaporator fans or condensation fans. Any modern supermarket has a machine room out in the back of the store somewhere.

In the last 20 years it is common to have 2 racks of compressors. One set is for all the low temperature freezers and the other is for the medium temperature cases. Where I live these systems have 2 condensers. One is on the roof. This is used in the summer time. The second one is located in the buildings ductwork. This condenser is called a reheat coil. That is the reason it is in the ductwork. It reheats the store.

The doors do save energy. Super markets are very cost conscience. If they can save a nickle they will.

I reread your post. Open cases, as they are know, have air curtains. They aren't quite as good as doors but the way they figure it is if you have 2 hands free you will pick up 2 -six packs of soda pop instead of 1. But yes it is an energy lost but not as bad as you might imagin.