Space bags are a good idea, but my experience with them makes me think that they are a work in progress. I bought a large space bag to store some things in the attic. I loaded it up with old stuff that needed to be stored and sucked the air out of it. My problem came when I moved it in to my attic. I carefully lugged it up up the attic stairs and found a place for it. When I was about to leave it there indefinitely I heard a low hissing sound. I examined the bag and noticed that it was filling back up with air. It seems that I bought a defective bag.