These bags aren't nearly as good as they look on TV infomercials.
The zip lock part tends to come open and they tear very easily.
We used them for one year, then switched to regular old garbage bags, tied tightly.
The "vacuum seal" is nothing but a marketing
trick. There is still ambient air in the bag after you seal it. A household vacuum does not work like a vacuum pump in a lab does. There is still air in the bag after your "vacuum seal" is done.
Save some $$ and pick up some Hefty bags and tie them so no air can get in or out.
To save space, squish stuff down yourself.