"Clear Vue Versus Oneida" A REAL Test

[Cecil Arnold]

A cynic may wonder if the Clearvue (Bill's design) doesn't include a 5 hp motor not only to be safe, but to be considered a 5 hp cyclone, competitive with other more expensive 5 hp systems. The specs look more like a 3 hp system to me, and it is price competitive with some of the other 3 hp systems.

If I have misread the specs, I welcome your input

Charlie,

I'm about as cynical as they come and would agree with your conclusion. I wonder if they used the motor in an attempt to get a desired SP through 6" pipe, since the CV uses that diameter inlet and the other two brands have 7" on their 2 hp & 8" on their 3 hp IIRC. Regardless, I think we all need to read as much as we can stand then make our buying decision. That's why they make Fords and Chevorlets, or Felder, Mini-Max, and Format. The real problem, as I see it, is that there is no modern, reliable, real world, standard for small shop DCs. We are faced with salesman's pump, obfuscation, and owner loyalty to sort through while attempting to get the best product for our $$ and equipment layouts. I guess in the final analysis, I don't really care how many angels can dance on the head of a pin, I just want something that sucks and keeps the air clean.

[Jim O'Dell]

But think about all the motors used for this purpose, whether they be 2 hp or 10 hp....they all run at the same speed, right? More horsepower will not give you more CFM, unless there is a bigger load causing the motor to drop in speed.. The impellor at the same speed, regardless of hp will produce the same air flow. The extra horsepower will keep that speed, and therefore air flow, at the same rate easier when a bigger load is placed upon it (I would think the extra load would be another blast gate open).
An analogy would be two identical vehicles. Trans and rear end and tires exactly the same. Only difference is the engine. One has a 200 hp V6, the other a 300 hp V8. Both vehicles will travel the same speed at the same RPM. Why have the bigger engine? Which one is going to tow a boat easier? Right, it all has to do with the load. Several have used 2 hp Delta motors on the Pentz home built cyclones and it has worked fine.
Effeciency of the impellor does not change with hp. My limited knowledge of impellor design leads me to believe that they are designed to work their best at a given speed. Higher speed may not lead to higher CFM. Although the design of the impellor could dictate what it needs to drive it effeciently. I know a blade in water will cavitate in certain conditions. I don't believe air has this same problem, but does anyone know if something similar happens? I know some prop driven airplanes have a variable prop to lesson some sort of reaction of the prop with the air. Jim.

[Jim DeMarco]

Well said Jim, this is the big missconception many manufacture try to seel HP to the consumer. If you read my prior post on this topic, the ONLY thing that matters in a properly sized DC system is velocity, and pressure drop at the DC. Granted, as you stated, this all assumes that the impeller is running at it's designed speed!

[Dennis Peacock]

Well said Jim, this is the big missconception many manufacture try to seel HP to the consumer. If you read my prior post on this topic, the ONLY thing that matters in a properly sized DC system is velocity, and pressure drop at the DC. Granted, as you stated, this all assumes that the impeller is running at it's designed speed!

EXACTLY!!!!!! What gets me is why even get on a HP kick?

[Randy Denby]

Jim, one thing I believe you missed is that rpm is the same, but diameter of the impellor/ depth of the impellor/ curve, etc changes to take advantage of a higher horsepower motor. Designed right it will draw more cfm at a higher static . But installing the same impellor on a 2 to a 5 horsepower motor will not have any advantage unless the 2 hp was overamping .

[Jim O'Dell]

Unconciously that's what I alluded to when I said something about the impeller design might dictate the hp rating of the motor. Thanks for making it clearer! Being able to draw higher CFM at a higher static is the loading that allows the higher hp to handle the task easier, like pulling the trailer behind a vehicle.
I also think that Ed has gotten some good help with impeller design, going from the original 14" Sheldon impeller to a 15", and now a 16" available, and no recommended increase in hp. Maybe this was his design, or maybe Bill Pentz's hand is helping this too. I haven't heard for sure, but haven't asked. I think the one I have is the 15", but could still be the 14". Jim.

[Noah Katz]

I believe that compressor duty means it has high starting torque, and that SF (service factor) =1 means that it can run continuosly at its rated FLA (full load amps).

[Pete Bradley]

I believe that compressor duty means it has high starting torque, and that SF (service factor) =1 means that it can run continuosly at its rated FLA (full load amps).

The Service Factor indicates the amount of continuous overload the motor can be subjected to without damaging the motor.

The Duty Cycle is the ratio of time the motor can produce rated power to total time. For example, some compressor-duty motors can't deliver rated power continuously, they need a percentage of cool-down time.

Pete

[Curt Harms]

EXACTLY!!!!!! What gets me is why even get on a HP kick?

Talking about H.P. fits the sound bite model. Talking about C.F.M @ S.P. doesn't. When's the last time You heard (inset your favorite shill here) talk about air flow and static pressure?

Curt