Hoover's Efficiency and Performance Ratings
Are They a Quest to Communicate or Confuse?
Rating the suction motor for its ability to
produce suction with
air flow is one of the most
misrepresented and misunderstood aspects of vacuum cleaner technology.
This confusion has been accentuated by many manufacturers in their attempt
to make their products appear superior to others.
The vacuum cleaner industry has established a standard for
measuring the Effectiveness of a vacuum cleaner although I have
never seen those ratings published. A number of years ago someone at
The Hoover Company
came up with the idea to take the Effectiveness Rating and divide it
by the Amperage to arrive at what can be
called an "Efficiency Rating". This was
a step beyond the industry's standard and resulted in a relatively
meaningless specification. Although it was derived from the
effectiveness of the vacuum cleaner, it had very little, if any,
value when comparing Hoover vacuum cleaners to those from competing
companies.
Hoover's manner of displaying this Effectiveness Rating caused a great
deal of confusion among the shoppers. Initially when they started using
this specification, it was displayed without the amperage rating in their
literature and at conspicuous places on their vacuum cleaners. You had to
locate the small specifications plate near the bottom of the cleaner to
determine the cleaner's amperage rating. Also, the formula was stated in
a very confusing format as shown in the following example:
A quick glance at this often gave the impression that the amperage
was 18.0. To add to the confusion, the number was displayed in a
very large font in a similar manner to how competing manufacturers
displayed their amperage ratings. The actual amperage was only 7.2 Amps!
As a result of some challenges in court, Hoover decided to display the
formula in a better format, showing the amperage rating of the cleaner as
well. Even after this change, far too many shoppers were still being
confused and mislead by Hoover's "Cleaning Effectiveness per Amp"
(Efficiency) Ratings which were displayed prominently on their vacuum
cleaners. The amperage rating is typically not shown as large and as close
to the efficiency rating as it is in the example below:
Apparently to help clear up the confusion about the Effectiveness Per
Amp rating, Hoover added a sticker to the side of their uprights which
reads as follows:
Rating SystemThe cleaning
Effectiveness Per Amp number is not an Amp rating. Amps do
not measure dirt removal, only the amount of electricity used. Cleaning Effectiveness Per Amp is determined by dividing this model's
Cleaning Effectiveness* by its Amps.
*CLEANING EFFECTIVENESS is the
percent value obtained from dividing: (a)the geometric mean of the amount
of embedded carpet dirt removed in testing under ASTM Test Method F608-89
by (b)the value 29 (the geometric mean of the midpoints of the % dirt
pickup scales selected by Hoover as a reference for its rating
system).
A rating of twelve amps is the maximum permitted for any appliance
which plugs into a standard household electrical outlet. If you see a
rating larger than twelve on a vacuum cleaner, it is probably an
Cleaning Performance Rating,
not Amps! Typical amperage ratings on
uprights are in the seven to twelve range, while Hoover's "Cleaning
Effectiveness Per Amp" (efficiency) ratings were in the seventeen to
twenty-two range on their upright cleaners rated at only seven to eight
amps. Described below is Hoover's newest rating method called "Hoover
Cleaning Performance". It results in values between eighteen and
thirty-one.
When Hoover introduced their WindTunnel Upright
Series they introduced yet another rating method. Since all the
uprights in this series were rated at twelve amps, the use of a "Cleaning
Effectiveness per Amp" rating didn't make much sense. Someone at The
Hoover Company got the lofty idea to use
"MACH" numbers to represent how
many deluxe features are on their various WindTunnel upright models. This
rating has nothing to do with power ratings nor cleaning performance since
all Hoover WindTunnel uprights are rated at 12 Amps and clean about the
same.
The Hoover uprights with "Cleaning Effectiveness Per
Amp" or "MACH" ratings have pretty well dissapeared today, being replaced
by yet another rating method called "Hoover Cleaning Performance" as shown
below:
To help prospective customers to better understand this rating, Hoover
describes it on their boxes as follows:
Hoover Cleaning Performance This
Hoover Cleaning Performance System is for comparing the Relative
Progressive Performance of Hoover uprights only and not for comparison
with any other brands. The majority of this rating is based upon the
American Society for Testing and Materials (ASTM) carpet cleaning
effectiveness testing (ASTM Test F608). Other performace factors include
hose power (ASTM Test F558), surface litter cleaning, hard floor cleaning,
edge cleaning, cleaning width and air filtration.
While it may be of some help when comparing between various Hoover
models it is completely meaningless for comparing between Hoover products
and other brands.
Hoover chooses to put a strong emphasis on a vacuum cleaner's cleaning
effectiveness. Perhaps these expressions of efficiency or performance were
developed in an attempt to show that emphasis to prospective customers.
Although we at Ristenbatt Vacuum Cleaner Service choose to promote and
sell Hoover vacuum cleaners, we are concerned about the undesirable
effects of the confusion caused by these non-standard expressions of
efficiency and performance. For more help with the confusion of power
ratings and to get a better understanding about how these ratings apply to
actual cleaning effectiveness, see our article on the Power of the Suction Motor.
There are many important performance aspects of a vacuum
cleaner system which you can read about in our article on
Identifying Good Performance Factors. These
include the Power of the Suction Motor,
Effects of Brushing Action,
effect of internal resistance
on the Air Flow through the System,
as well as the Efficiency of Paper Bags and
Filtration Efficiency - HEPA, ULPA, etc.
To choose a durable vacuum cleaner which will meet your cleaning tasks
and preferences, see our articles on
Identifying Durable Designs & Construction
and Match Your Tasks and Cleaning Style. A
good, knowledgeable sales person like those at Ristenbatt Vacuum
Cleaner Service can help you determine which vacuum cleaner
will be the best for your particular cleaning needs and preferences.
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