The original SmartFan® fan controller was a TRIAC design Control Resources made in 1984. Our product offerings have come a long way from then, including our 5th generation TRIAC based fan control, the Nimbus II. Other AC fan control technologies we offer include the Stratus II VFD (Variable Frequency Drive) and the Cirrus-ECM (Electronically Commutated Motor) drive.
What Fan Controller is right for my application?
When a DC fan is available, and DC power is accessible, nothing beats a DC control for energy savings, cost-effectiveness, compact size, safety, or controllability. When a DC control is going to be impractical for your application, refer to the table and chart below to help guide you to the best technology for your application.
Control Technology Overview: TRIAC, VFD & ECM AC Motor Speed Control
 | TRIAC Control: Nimbus II, Nimbus If system cost is the number one concern, choosing an induction motor [Permanent Split Capacitor (PSC) or Shaded Pole] and a compatible TRIAC control may be the way to go. TRIAC controls also tend to be more energy efficient at higher speeds than VFDs. Drawbacks of this technology include relatively high minimum speeds and potentially nonlinear control curve (input signal vs. motor speed). Please check out our AC Motor Compatibility page for an explanation of the TRIAC AC motor speed control motor requirements and risks. |
 | VFD Control: Stratus-II Not all AC motors are TRIAC controllable. In many of these cases, an inverter duty motor can be successfully controlled with a Variable Frequency Drive (VFD). VFDs tend to be more energy efficient than TRIAC controls at lower speeds and can be run at lower speeds. Drawback to VFDs include, controller cost, size and potential bearing noise. Please check out our AC Motor Compatibility page for an explanation of the Variable Frequency Drive AC motor speed control motor requirements and risks. |
 | ECM Control: Cirrus-ECM In recent years, the availability of ECM motors has greatly increased. These are basically DC motors with built-in transformers allowing them to be powered from the AC line. As a result, these motors are the most energy efficient and easiest (inexpensive and accurate) to control. But of course there is no such thing as a free lunch. ECM motors can be pricey and are not always available in the size required. |
TRIAC, VFD & ECM AC Motor Speed Control Comparison
| TRIAC / Phase Control | Variable Frequency Drive | ECM Control | |
| Energy Use | Good* | Good* | Best |
| Controller Accuracy | Good | Better | Best |
| Low Speed Capability (<50%) | Good | Better | Best |
| Motor Availability | Better | Best | Low |
| Induced Bearing Noise | Better | Good | Best |
| Controller Size | Small | Large | Small |
| Controller Cost | Low | High | Low |
| Motor Cost | Low | Low | High |
Custom AC Fan Controls
We understand that sometimes, off-the-shelf solutions might not exactly match your requirements. CRI specializes in custom design and manufacturing and the majority of our business comes from custom product development. Our expertise lies in creating AC Fan Controls that align to your specifications. Contact us with your detailed specifications and let us engineer the precise solution you’re searching for.
OEM Supplier + Exclusivity for OEM Applications
Control Resources is an OEM (Original Equipment Manufacturer) supplier of fan and motor speed control products, offering reliable solutions for manufacturers and integrators. Our products are not intended for end-user/after-market applications. Thorough system testing must be done to ensure compatibility of fan and control.
Standard SmartFan® AC Fan & Motor Speed Control Products
| Model | Current Rating | Motor Type | Control Technology | Control Options | Input Voltage Range | Programming Options |
| 4A @ 40ºC | 1 Phase or 3 Phase Inverter duty | VFD | Temperature, analog (0-5V, 0-10V, 4-20mA), transducer, potentiometer, MODBUS, fixed speed | 104 – 253 VAC |  Programmer MODBUS, or Factory set-up |
 | 7.0A @ 40ºC | 1 Phase TRIAC controllable induction motor | TRIAC | Temperature, analog (up to 10VDC, up to 20mA), transducer, fixed speed | 65 – 277 VAC | SmartFan® Navigator |
 | 7.5A @ 40ºC | 1 Phase TRIAC controllable induction motor | TRIAC | Temperature, analog (2-10 VDC, 4-20mA), transducer, fixed speed | 95 – 250 VAC | Dip Switches or |
| Note: Nimbus is not recommended for new designs. Please see the Nimbus II above. | ||||||
| N/A | ECM | ECM | Temperature, analog (0-10V, 0-20mA), transducer, fixed speed | 22- 26 VAC | Programmer or Factory set-up |
 Speed Control | Control Resources specializes in customizing existing designs as well as providing all new custom controls to meet your specification. For more information visit our Custom SmartFan® Controls and Alarms page or talk to one of our engineers. Email: sales@controlres.com or call 978-486-4160. | |||||
*TRIACs are often more energy efficient at higher speeds, Variable Frequency Drives are more efficient at lower speeds.
Applications – TRIAC, Variable Frequency Drives, & ECM AC Motor Speed Control
 Pump Control SmartFan® AC motor speed control products are capable of controlling small AC pumps. |  Clean Room Pressurization SmartFan® AC motor speed control products can be used to help keep positive pressure in clean rooms. |  Humidity Control SmartFan® AC motor speed control products can automatically regulate fan speed when connected to a humidity sensor. |  Ventilation SmartFan® AC motor speed control products can be used with a ceiling fan, attic ventilator or duct fan to remove hot air or noxious fumes. |
Connect with CRI
Call us at 1-978-486-4160 or email to discuss your AC Fan Controller needs.