Wanting to Test Vacuums

[z67danco]

I’d like to gradually start testing vacuums, but I don’t know where to start. I don’t want flaws in my experiments, but that’s something I’ll have to learn as I go, refining the process over time. Eventually, I would like to have a way to get my experiment(s) analyzed. What equipment would be ideal to start out with? What tests? ASTM?

Is there any database for vacuum-specific research? Or air purification?

I’m primarily interested in filtration performance, and dirt extraction ability. I’m trying to figure out what the most common type of carpet is in U.S. residential houses so that the carpet samples I acquire for testing will be better representations of carpet performance than if I were to use my own home’s carpet. I do want to test performance differences on special types as well. Some vacuums do well on one carpet, but struggle on another.

As far as filtration, that will probably be more difficult due to the conditions being more challenging to control at home; but I’d like to test for air leaks and particle retention at PM 0.1 and PM 0.3. Maybe I could build an air-tight chamber, but how would I test for PM 0.1? Particle counters are interesting and useful but they don’t cover all the bases. I still want one, though.

What do I have to test currently? Kirby, Rainbow, Miele, Sebo, Dyson. My primary daily driver is a Miele C3, while my V15 supplements daily spot-cleaning and touch-ups. We have a a few indoor pets, a good mix of carpet and hard flooring, and a lot of traffic, so daily vacuuming is a must.

 

[cheesewonton]

Do some reading on how HVAC techs measure turbulent airflow in a tube or pipe. That will give you some insights on how to use an anemometer properly, and the math to correctly calculate airflow from air velocity and the surface area of the hose, tube, pipe or whatever the air is moving though.

Understand that suction and airflow are inversely related. As suction increases airflow decreases. The larger the hole, or orifice, the vacuum is breathing through the greater the airflow but suction is less. As the orifice size is decreased or restricted suction will increase and airflow will decrease. At sealed suction there is no airflow. If you ever wondered why vacuum motors seem to speed up when you put your hand over the hose it is because the airflow is stopped, unloading the fan and allowing the motor to spin faster ( and overheat ! ). When you take your hand off airflow resumes and the motor slows down as it works to spin the fan(s) against the mass of the air flowing through it.

If you look at some vacuum motor performance charts you see that as suction increases amp draw and wattage drop.. That is because more suction means less air on the fan(s) and less load on the motor. You can get a lot of insights into vacuum motor performance from studying their performance charts. The Ametek website has what they call "Product Bulletins" for their motors that show all these relationships as well as how air watts are calculated from suction and airflow at different size orifices.