How often should you change your vacuum cleaner bags? Often! Whether you have an upright or canister vacuum cleaner, changing your bags frequently is vital to maximizing your vacuum cleaners ability to filter dust and debris as well as maintain maximum suction. Changing your vacuum cleaner bags is similar to having your oil changing in a car; wait too long and your inviting unnecessary and potential expensive problems for pennies on the dollar.
Upright vacuums are increasingly being designed in a manner similar to a canister vacuum. The vacuum cleaner bags helps to protect the motor from damage as well serve as an important part of the filtration process. This make the quality of vacuum bag you utilize very important. Cheap vacuum bags may break or lack the ability to suppress allergens from being redistributed as you vacuum.
If you own regular sized upright made by Kenmore, Sebo, Panasonic, Sanyo, Hoover, or Sharp, your vacuum cleaner bag probably sits in front of the motor filter. The motor or pre-motor filter is vital in protecting your motor from debris. Motor filters need to changed or cleaned as they can become caked up with debris, but a high quality vacuum cleaner bag will minimize this need and help protect your motor.
One of the quickest ways to shorten the life of a canister or upright is allowing the vacuum cleaner bag to overfill and/or break. A vacuum cleaner may be able to pick up a small hard object, but if this object causes your bag to break, the only thing protecting your motor from sucking all this dust and dirt inside of it is the filter above it. The filter will help, but it will eventually clog. A motor filter covered in debris will hamper the performance of the vacuum and place undue stress on the motor.
I recommend changing your vac bag once a month or two. Check your filter bag this frequently. Don't trust sensor lights if you vacuum has them. If your vacuum bag is half full or better, you will reduce the suction your vacuum exerts during cleaning. A vacuum bags that is less than half full will allow your vacuum cleaner to perform adequately.
I like hypo-allergenic bags, especially the white ones that feel like cloth. They are treated to reduce dust and dust mites from being reintroduced into the air, and they keep the vacuum chamber a lot cleaner than some cheapo supermarket quality vac bag. It's not really that important in most cases who makes the bag, but how the vacuum bag is made. I sell plenty of after market vacuum bags to my customers with no complaints or loss in performance.
Even if you have a Kirby or Oreck for example, a broken vac bag will not cause damage to the motor, but you'll have a mess on your hands as soon as you unzip the exterior vacuum bag. You will maximize the filtration abilities in any cleaner that utilizes bags. PS: Don't forget the filters, they need to maintained as well.