The term HEPA stands for the phrase "High Efficiency Particulate Air" and refers to a certification level. Filters that carry the HEPA certification have proven to filter out at least 98 percent of particulate dust.

There is some debate about how effective an upright style is at containing the dust that is suctioned up. Some say that there is a tendency for uprights, because of their design, to release at least some dust back into the air, before it reaches the filter and bag.

Others claim that the upright models do an effective job of minimizing emissions of dust during vacuuming. Overall, it is the consensus that upright vacuums with HEPA filters will do a better job of containing the problem with dust that is spewed back into the atmosphere while the vacuum is running.

Bagless upright vacuum machines are becoming increasingly sought after by those who dislike handling the vacuum bags. While in many cases the bags make it easier to handle the debris from vacuuming, some poorly designed models make it difficult to quickly and easily change the bags. People also dislike having to purchase the replacement bags and prefer to buy the filters that bagless vacuums use, since they need to be changed less often.

One drawback to the bagless upright model is that the collection reservoir, or dustbin, must be emptied without the benefit of a bag to contain the particulate. Because of this, those who are very sensitive to dust or who have severe allergies would do well to purchase an upright that uses vacuum bags and a HEPA filter, or should make sure that someone else in the household is available to empty the dustbin when needed.

Of the many upright models, the Eureka Boss SmartVac 4870 has earned high praise among reviewers. This Eureka vacuum retails at around $150 and has a HEPA filtration system which is contained in a completely sealed unit. Also, this upright Eureka has a hose that is clear to help see and avoid clogs, and a number of on-board attachments.

In addition, with regard to comparisons for noise, this Eureka vacuum model runs more quietly than many other more expensive units that were tested. Reviews also showed that the Eureka 4870 performed well on carpeting, as well as with floorcare and on pet hair tests.

Another highly rated upright is the Kenmore Progressive model 35992. This unit was considered to be the best vacuum in the retail price range of $300. It performed equally as well as the Eureka vacuum did on carpeting and bare flooring, but the motorized brushroll also helps to propel the unit so that it is easier to use and maneuver. In addition, the Kenmore performed better in cleaning stairs and on upholstery. It also sports a HEPA filter and received excellent scores for low dust emissions.

For those who are troubled with allergies, robotic vacuums can be a helpful addition to an upright vacuum, to help keep dust to a minimum. The robotic vacuum units allow a homeowner to assure that their premises are vacuumed daily which helps to control particulates in the air. But, the small automated vacuums should not completely replace a full-sized upright unit and are best used in combination, with the robotic unit handling daily vacuuming and the upright taking care of the deeper cleaning needs.