Is Leaving Your Air Conditioner On All Day Better Than Turning It On and Off?

It takes time for air conditioners to completely cool down a room. During that time, it is an energy hog. This is what led many people to believe that keeping their air conditioner turned on all day will help them save energy. But is there truth to this?
https://www.tumblr.com/iphltdc....a/720734039165796352