Summary :

 

The temperature of the environment generally below 5 degree Celsius during the winter. However average temperature setting of the refrigerator ( not freezer) is 0 to 10 degrees.Then let the air flow inside of the refrigerator . It is similar to keeping the vegetables milk etc outside of the window.

 

Concept is get the air from outside during the winter and control the inlet. Am I violating any law ?. As today we use the heater to warm the house and then cool the things using refrigerator.

 

BackGround :

 

Summary :

 

It is very simple idea  and easy to implement it.  You may fine tune it using air filtering etc ...