John posted this on ICS, thought I'd move it here for discussion.
Here are some comments from the Vac Motor Executive. A neutral guy with no axe to grind. He is more then fair and honest. This was not a competition it was a comparison of similarities and differences to give the PCC's info for making any choice they like. All the machines cleaned carpet. Some may have been a little faster than others, but that is somewhat subjective. It's like, which car do you prefer? Chevy, Ford or what ever. There were no Yugo's there. As far as new units are concerned, they were all new except one, and the invitation to that manufacturer was declined. The guys evaluated what they had. It wasn't designed for anyone to look bad but instead to provide info to the industry.(like water lift and amps per cord) If you truly feel that a more "independent third party" is needed let's agree on who and where. Mytee will be glad to participate.
John LaBarbera
Mytee Products Inc.
From: "Dennis Mancl"
Date: March 6, 2009 5:58:13 PM PST
To: , "Nathan Pepper" ,
Subject:
Mikeyfest Comments
Hello Gentlemen;
Thanks very much for asking me to be part of
Mikeyfest --- it was really great to meet so many really interesting people and review the many wonderful products --- there was certainly much for me to learn.
Some random comments related to testing and performance are noted below:
1) Many different types of performance measurements were made, many of which do not necessarily directly relate to cleaning ability.
2) ?CFM? readings were taken with a 25 foot hose with an open inlet condition --- only the CFM meter was on the wand end of the hose. This CFM value indicates the airflow (Cubic feet of airflow per minute) with an open hose condition. Since a hose must be connected to a wand and integral floor nozzle that reduces the orifice (and reduces the CFM) as used on carpet, then the CFM reading cannot be directly used to indicate the nozzle vacuum in actual application.
3) Unit inlet port sealed vacuum --- These readings were also recorded and indicate the sealed inlet vacuum with zero CFM (airflow). Again with no airflow, then water could never be picked up off the floor and moved into a recovery tank. Both vacuum and suction together are required for effective pick up and transfer of the water off the carpet and into the recovery tank.
4) Average Nozzle Vacuum --- these readings were also recorded. The wand nozzle had a hole tapped into it about 3? above the floor and in the middle of its 12? width. These readings were recorded both with the wand moving forward (pushed) and also the wand moving backward (pulled). The pull and push wand vacuum readings were added together and then divided by 2 to yield an average wand vacuum. My opinion is that this reading is a better indicator of the units ability to contribute to the extraction capability (how fast can water be picked up).
5) Boosters --- Testing was run using 125 feet of 2? hose comparing the 5 units. The boosters seemed to level the playing field performance. Without the booster the wand vacuum pushing readings ranged from about 22 ? 49 inches. With the 2 stage Mytee booster 25 feet from the wand (still 125 feet total) the wand vacuum readings ranged from about 50 to 63 inches. With the 3 stage Mytee booster 25 feet from the wand the vacuum readings ranged from about 53 ? 69 inches. Again the readings were much closer with a booster than without.
6) Less sealed vac with 3 motors than 2 --- One unit tested runs normally using 2 motors butr can have a 3rd motor turned on also. With the 3rd motor turned on the sealed vacuum went down but the open CFM increased. If a lower (not balanced) vacuum motor is used for the 3rd boost motor, then at sealed suction the higher vacuum motors can actually leak air through the 3rd motor reducing total sealed vacuum. On the other hand since at the open hose CFM test condition you are operating a very low vacuum, then this 3rd motor still raises total open hose CFM.
7) Booster Power --- Generally the 2 and 3 stage motor boosters helped. However if the main vacuum source has very high power motors, and if the booster were relatively low power, then the booster motor would have airflow though it backwards acting as a leak rather than ?boosting? performance. Therefore the system should be designed, balanced and tested as it is intended to be used to make sure desired results are achieved.
8) Air Series versus Air Parallel --- Which is better? The honest answer is it depends. Either can be better or worse depending on the total system design. Factors effecting the answer include motor stages, motor power, hose size, hose length, hose smoothness, inlet filter restrictions, exhaust filter restrictions, hose cuff restrictions, wand width, wand length, wand opening detail within opening, leaks at any and all joints. All of these things collectively define system performance which then determine optimum air series or air parallel performance. It is a good idea to test any theories by looking at your nozzle vacuum when used for extraction on your most typical cleaning surface.
9) Water pick up --- This was also tested and was rather subjective. It was agreed that that units all generally picked up most of the dispensed water given enough time to vacuum it back up. Higher nozzle suction should pick up quicker, lower nozzle vacuum likely takes more time. Some people felt 100% water recovery was achieved --- I find this difficult to believe as in all cased the remaining carpet was at least somewhat damp. I would expect some correlation to how high the nozzle vacuum is --- especially regarding how long the recovery takes. If a recovery test is run on a initially dry carpet I would expect the recovery to be lower than with an already wet carpet that will thus more readily give up the moisture. If a carpet were quite wet initially then you could even get more water back than you even put down? So anyway we must be a little careful in comparing these values.
To All --- Thanks for inviting me to be part of this --- Hoping my comments are somewhat helpful.
Dennis Mancl