I could have sworn it was in the parent handbook!!  That, and the line you have to perfect . . . 
"Close that door, do think we're made of money?  I'm not paying to heat/cool the entire planet!"

Our kids are gone but Hubby has a few bad habits.  And we live in the country.  Fortunately one of the wild critters haven't wandered in to cool off or warm up.

It moves faster than you can calculate and when you come up with a figure, its already after the fact. In this case...HOT. Shut that door and keep it shut

I'm thinking you could measure it in nanoseconds.

Kevin J. May I don't know exactly, but it doesn't take very long for the heat to overtake the cool.

Instantly?

I remember when I was a child my father asking "Do you think we own the electric company?"

It happens too fast. I was always telling the kids...shut the door. And of course the opposite happens in the winter

SHUT THE DOOR - LOL the outside doesn't need any help with my A/C

As my husband always yells - "SHUT THE DOOR, WE'RE NOT A/CING THE OUTSIDE"

LOL

I love Susan Emo 's answer.... love it...

Kevin J. May I remember those type of questions in my Engineering Exam!

Pretty quickly. I can feel a difference in less than 30 seconds.

Seconds, it seems!

Probably 15 minutes to feel the difference for the entire house. 

At GE household refrigerator development there is a test called Heavy Usage Test(open and close the door). It assumes a family of 7 will open close so many times a day. Doors have to be tested 250,000 times to pass the product requirement. The doors have light switches and sometimes switches will break down.

The power consumption went up from 40% running time to 100%.  The freezer storage suggests that ice cream start thawing out..... Engrs who design the product have a cow when their family members open and close doors constantly like your children.

John Kerry would be very concerned , AC is more dangerous than ISIS !

Kevin,

I heard my father saying what Susan Emo said...A

If you have kids it will never get cool

It happens in my house all the time and now will be watching for the answer so I can remind my family members.

Takes me back to my grandmother--shut the door

I don't know in minutes Kevin J. May, though do know that the first thing you will hear is the a/c 'working' longer and harder, to continue to cool the home.

1/2 hour?

The other day an odd thing happened because it was so humid. House was AC & 74ish - went into the car to start it & pull it into the garage. I was smoking in the car!  I sat there laughing for awhile & then my glasses fogged up.  It was a great science experiment!  

I have never tracked this type of information nor conducted any related experiments.

Immediately!  Right after I start yelling "Hey, I'm not paying to cool off the neighborhood!"  That's when my "cool" fades away.

Too long.

 5 minutes.

My wife has this habit all the time and I will never get her train to close it all the time.

Great question for which I do not know the answer, except rather quickly!

thanks.

Uh, oh --- another math question.   

No clue... doors don't stay left open and don't want the bugs. Also, have no more young kids at home and the youngest grandkid is going on 18.

Some days you want to beat buyers agent who leave stuff like this on.

Have had some huge heat and water bills due to stuff that got left on during showings.

Well, I thought I might find the answer here!  But, like the others, my Mom's words, "Shut the door!  We're not paying to cool the outdoors!" echoes in my ears!