!2 volt DC Motor for 24/7 fan

I have a composting toilet which requires a fan in the exhaust chimney which runs 24/7. The fan is an 7.5-inch fan mounted directly on the motor shaft in an 8-inch duct. Over the past several years I have been using Clifton Precision motors Model No. DH-2250-R-1. These motors are 2.25 inches in diameter and4 inches long, and have no speed or HP data printed on them. The company that installed the toilet had bought a lot of these from Clifton Precision and I bought several from them. The motors run for about two years before the brushes wear out. Now Clifton Precision no longer makes these motors and the toilet company is out of business. I have just installed my last motor and I'm having trouble locating a suitable replacement. I would greatly appreciate advice on where to purchase similar motors.


  • BB.
    BB. Super Moderators, Administrators Posts: 33,479 admin
    Re: !2 volt DC Motor for 24/7 fan


    Sorry, I don't have a replacement motor for you... Can you use a brushless DC Fan for your application? I was checking around, and the typical DC fan seemed to be rated at ~8-13.2/13.8 VDC. The high range is less than a battery powered system's voltage range (14.5 - 15+ VDC for fully charged batteries).

    Perhaps, just get a 12vdc fan from a surplus store and run it for a while and see if it works (without failing).

    Otherwise, I would get a small inverter, like this:


    It uses about 5 watts with zero load, 85-87% efficient at load.

    Measure that current of the the current DC fan motor and convert that V*I=Watts into a, roughly equivalent AC sized motor. $200 for the inverter + $xx for the AC motor (for example, from www.grainger.com -- need business license to purchase direct)--no more brush issues...


    PS: The only brushless fans I found that would work on a Battery or Solar Panel Direct system seemed to be 48 VDC models (32-80 VDC range)... I would guess that this won't help you here.
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • System2
    System2 Posts: 6,290 admin
    Re: !2 volt DC Motor for 24/7 fan

    You may look around electronic surplus vendors and find a 12 volt brushless motor/fan combo, that was once used in computer type equipment. I switched my home air exchanger to these types of motor/fans, about 15 years ago and so far, running 24/7, have never had a failure. Mine have ball bearings, but that shouldn't be a necessity. I also installed a switch, to select 12 volts for full speed, or 6 volts, for reduced airflow and power.
    Here in Canada, such things are often available in the Surplus section of Princes Auto, a country wide chain that handles many weird and wonderful things.
    You could even use 2 or 3 smaller ones side by side, if one didn't give you enough air flow.
    By the way, my air exchanger energy usage dropped from about 150 watts, down to 24 watts on high speed and still provided plenty air flow for me.
    Good luck.
  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    Re: !2 volt DC Motor for 24/7 fan
    patf wrote:
    The motors run for about two years before the brushes wear out.

    Are the brushes not replaceable ? Motor mfg should be able to supply brushes.
    http://www.mcmaster.com/ search for "Motor Carbon Brushes" there are about 40 styles, below the AC Motor Capacitors

    If you reduce the urine load in the toilet, can you use a smaller fan ?
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