my favorite central vacuum units
I have 8 of them throughout my apartment and I use them all free standing. My flomaster uses 8 gallon bags where as the silent master uses 12 gallon bags I think, it also uses a flow through motor rather than a bi-pass motor, I know there is a lot of debate on whether the bi-pass motor is better, the flow through motors can be just as powerful though.
I have several favorite central vacuum units for different reasons. My Purvac Barracuda is very quiet but very powerful, 151 water lift and I think about 144 CFM. My Vacumaid sr800 uses the Ametek 8.4 inch double fan bi-pass motor, this is the most powerful motor that Ametek offers for 120 volts. I'm also really fond of my Vacumaid garage vac pro, it uses a 5.7 double fan flow through motor, 138 water lift and 138 CFM. It is designed to give you the power of a central vacuum without pipes, rather than a pipe in-take, there is a hose in-let right on the unit. And then there's the Drainvac Atomik, it's so small that it can set on a counter but it has 125 water lift and I think around 140 CFM. It comes with a utility valve screwed on to the in-take making it very portable since it has a handle on the top for carrying, but you can easily remove the utility valve and attach a pipe if desired. Very awesome machines for sure. I wish my apartment had a 220 volt outlet, there are some two motor machines that I would love to have. There are some two motor units that use 120 volts but I've read that those do not work very well since the motors are rather small.
Mike