What is the most powerful central vacuum?

[centralsweeper63]

I was looking at some central vacuums for a large house, then I got distracted looking at triple motor central vacuums. I know there are filtex, thoromatic and airflo triple motor units. I know there is a copy of a filtex/ central vacuum international unit that sells a single, double or triple motor unit. They all have 7.2 inch motors! I know it was a three letter abbreviation, though that is all I remember. I was also intrigued by massive dual motor units ( E.G. vacuflo 960, cyclovac 7515, vacuflo db10max, etc) If you have experience with any of these beasts I would love to hear about it.

 

[cheesewonton]

Filtex. Wow, there's a name from the past. They used to make household canister vacuums in Los Angeles right after WWII. The bodies were made of the same material pegboard is made from. Now the brand is used for a central vacuum? Is it the same company or did somebody revive the name?

 

[panasonicvac]

The Vacuflo 960 has since been discontinued, so is the CycloVac 7515 but they do make a 7525 today. From your list, I'd recommend the CycloVac. You'd have the option of having it either in parallel or series, can be used as bagged, ton of power, and one of the quietest central vacs I've ever heard of at least for a split system.

 

[centralvacguru]

The Filtex name was bought out quite a few times over the last few decades and hasn't been used for central vacuums for a few decades in the USA. When they were in LA they used to make a few parts for MD and vice versa in the early 1960's. Even Lindsay Mfg trademarked the name early 2000's but since abandoned it. Filtex made units similar to MD in the 1980s including a (2) 7.2"-motor unit and a 3-motor unit. MD's original (2) 7.2" motor unit was a split system with the motors being the "DV" for "Dual Vacuum" and the "ST" for "Separator Tank". When the two were put into one unit it combined the letters making it our Model "SV". At this time, for our strongest unit, we recommend our Model S900 which has the same motors as the older S5.

 

[centralvacs1928]

Grant, that's interesting to know how the SV got its name! I like the hidden meanings in the old MD model numbers (E2 = Extra Capacity with 2 motors, right?).

I use a 35 year old SV at home (well, the motors are newer and they are 3-stage now) and it handles three retractable hoses plus about a dozen standard valves very well. Though an S5 (S900R) would be quieter, my unit is inside an insulated mechanical room and has mufflers on the exhaust pipes. Even standing directly above it on the main floor, I can barely hear it.

The triple motor units, were those originally created for Central Vacuum Inc in Chicago? Or did MD offer them before?

I did use a cart-mounted CFM3 earlier this year on a service call at the Detroit Masonic Temple...they had sections of their 1920s iron piping that had become completely filled with debris and I attempted to reverse-suction some of the non-working inlets. No luck. Ended up having to go down in the tunnel and remove cleanout plugs to manually ream/chip out the buildup in the 5" main. I think I vacuumed 5 or 6 Hyperflow bags worth of crud out of that piping.

 

[centralvacguru]

I love the pictures of the portable CFM3! Unfortunately it would make a poor clean out unit with only about 85" waterrlift.

MD first came out with the Model E3 (with three motors in air-parallel) figuring that more CFM would equal more cleaning power. Nick from Central Vacuum in Chicago then wanted it so we created the Model CFM3 for him to match in with his CFM2 that only had two of the same motors. When Ametek came up with the Acustek motor, we implemented those quieter motors and named it the QE3. Interestingly in the Chicago area, all of Nicks CFM3's were built with two external J-boxes: One to house the three mini-breakers, and one to house the wiring so the units could be hard-wired to meet the Chicago area electrical requirements.
If you look at the performance curve of the CFM3, it achieves it's peak performance at about 1.5" opening, something that is larger than anything we use in normal residential applications. One other problem that we found was that if one motor went out, the homeowner normally would not know it. The performance was still reasonable but the dead motor would spin in reverse as it was being sucked by the other two operable motors and there was a big air loss in performance. The user would complain that the system didn't work and I felt it started to hurt the cause of central vacuums so we pulled the configuration from our line up of units available.