Certain devices and technologies are available to ensure that doors automatically close themselves, either for security's sake or to help control accidental heat loss or gain.
Soft and Effortless Self Closing Mechanism for Full Overlay Hinge Application, Made in Austria, Kitchen Hinge Damper, Cabinet Door Soft Close Hinge Buffer
Automatic Aluminum Door Self Closing Mechanism for Door (DT-82) - China Door Closer, Door Lock
Self Closing Door Hinges - Kenwa America
Hafele 940.82.568 Sliding Door Fitting, Häfele Slido Classic 80-L, With soft and self closing
Door Hardware - Security Lock & Key
Automatic Diy Door Closer With a Bottle : 4 Steps - Instructables
Sturdy Iron Spring for Automatic Self Closing Doors Self Closing
4-inch Matte Black Door Hinges with Self Closing Mechanism
Self closing door closers - Soft close dampers, hinges
Soft Closing mechanism, for door,Smove, for installation in/on top
Self Closing Mechanism For Pocket Door -Pocket Door Accessories