Allergy Vacuum Facts

“Allergy vacuums” is a generic term, but more specifically, we’ll look at HEPA vacuums. HEPA (high-efficiency particulate arresting) vacs, just like HEPA air filters, filter particles down to .3 microns. They also must remove 99.97% of these particles in order to be called HEPA.

Some vacs use actual HEPA material; some use a different type of material but still filter down to the HEPA standard. Either type works well on allergens.

What’s the difference between a regular vacuum cleaner and a HEPA cleaner?

1. Regular vacuums do not remove particles smaller than 50 microns. These include dust mites and their parts, which are from 10-50 microns in size.

2. Standard vacs simply distribute and stir up the particulates they don’t trap. Allergy vacs actually trap the particles.

3. Conventional vacuum cleaners have a single-layer bag, allowing more dirt to pass through and clog up more quickly. Most allergy vacuums have double- or even triple-layer bags. These bags filter everything but the finest dust. Bags with more than one layer also allow the bag to fill more completely because each layer progressively filters finer particles so that pores do not become as clogged.

HEPA vacs are more expensive than most regular cleaners and also require filter changes; frequency depends on how often you use the vacuum.

Another type of vacuum that’s marketed for allergies is the “water bath” vacuum. The theory is that by bringing the dust into a water bath rather than into a dust collection bag, sensitive people will not have to come into contact with the dust that escapes during bag changes. The water wets down the particles, which then can easily be flushed down the drain.

While this is true, the problem with water vacs is that particles between 5-15 microns are only partially soluble in water, and particles below 5 microns are not water soluble at all. They will simply float to the surface, where they will become airborne again when exhausted by the vacuum. (Remember, dust mite excrement and body parts are less than 1 micron in size.)

In response to consumer concern about filtration, many manufacturers make claims that are somewhat misleading. Some say their vacuums capture “99% of all particles.” This may be true, but that could mean it picks up all the large particles and lets the smaller, lung-damaging particles get through. A vacuum with a paper bag blowing out mold spores, bacteria and dirt would also pick up 99% of all particles if particles are measured by weight or some other method.

Conversely, some manufacturers make claims that their vacuum “captures particles as small as 0.3 microns”. Again, this may be true, but it does not tell you what percentage of particles of this size it captures. Many vacuums will capture particles of this size. The key is that a true allergy vacuum has to be able to stop 99.97% of these fine particles.

General Vacuum Facts
Vacuums can be either canister or upright. This tends to be a matter of personal choice, but they do each have their pluses and minuses. A canister model has to be pulled along and it’s likelier to bump into furniture or scratch walls. (Some canisters have a rubber bumper for protection.) Uprights can topple over if pulled too hard or if you’re at the end of the cord.

The Motor
There are two common measurements of a vacuum motor: airflow and waterlift. Airflow is how many cubic feet of air the machine can move in one minute (expressed as CFM, or cubic feet per minute) without any restrictions such as bags, filters or flooring. Generally, the higher the airflow, the better; however, because manufacturers measure this in a lab and not when the machine is operating, the number can be deceiving. A motor with a high airflow rating may actually have a lower “true” airflow than one with a low rating but a more efficient design.

A more accurate rating is waterlift, which measures how well the vacuum can fight against restrictions such filters, bags and the floor. Waterlift is measured in inches. Usually, this measurement can only be done on a machine with a sealed-vacuum motor, because the vacuum filter creates so much restriction that the higher waterlift of a sealed-vacuum motor is required.

A sealed-vacuum motor looks like a can; fan blades are fixed onto the motor shaft and sealed by the can. This type of motor takes many small “bites” of air, whereas a regular vacuum fan takes fewer but larger bites of air. Vacuums with sealed-vacuum motors typically have higher waterlift and lower airflow laboratory ratings than those with a regular vacuum fan. Again, these ratings are all figured in a lab. In the real world—when the motor is put into a real machine with bags and filters sucking on the floor—a sealed-vacuum motor will create more airflow even though its rated maximum airflow is less than a regular vacuum fan.

Amps and Watts
Another common measurement of a vacuum is power consumption, expressed as watts or amperes (amps). This is a measure of power intake and is analogous to fuel consumption. If all motors were designed the same way, this would be a good measure of performance. However, some manufacturers use motors that are inefficient, so they consume more power and therefore have a higher watt or amp measurement. This is like designing a car engine to burn more gas and selling it on the basis of a high MPG. Higher watts and amps do not mean anything in terms of cleaning performance, but it might help you estimate your electric bills.

Information adapted with permission from Sebo Inc.