HVAC Manufacturing & Technology has developed patented variable orifice plate technology that is disrupting the market. Our variable orifice plate technology is the most economical way to measure and control low fluid flows over a wide dynamic range.

Variable orifice plate technology is sold as an all-in-one package, displacing multiple products & systems, including air terminals, venturi valves, flow measurement devices, IAQ dampers, VAV controllers, and actuators.

How It Works:

Typically, orifice plates are used for determining mass flow rates of fluid flow in industrial processes and are available in numerous sizes. The desired accuracy of the fluid velocity measurement dictates the size of the orifice plate. The higher the fluid rate through a given sized orifice, the more accurate the fluid measurement.

However, our technology allows us to measure the Vena Contractae at low Reynolds numbers accurately, simulating multiple variable orifice plates performance simultaneously in one size.

The new technology allows any type of a single size flow control device, (blade damper, round danger, rectangular damper), to operate as a variable orifice plate at low pressure. The technology can measure flows as low as 5 cfm with a single inexpensive transducer with a 500 - 1 turndown and flow accuracies of 3% (tested on calibrated flow stands). This allows one size to replace multiple size terminal units and eliminate millions of part numbers.

Additionally, the flow accuracy eliminates the GiGo (garbage in garbage out) scenario transpiring on current systems. Currently, zone devices are sending inaccurate flow measurement to the legacy software systems, where in turn inaccurate data is being transmitted to the fans and compressors, which result in higher energy costs. The flow accuracy eliminates the need for air balancers as the system is now self-commissioning in real time and eliminates the need for costly thermal transfer devices and associated piping in current systems.

The set point temperature in each zone is met with the exact amount of pulses of air to maintain the zone requirements. Thus, reducing the cost of the system and decreasing the time to completion of a building. A contractor can order the same size units, regardless of the zone requirements and install them anywhere in the building. Then the controls system operates the units and self commissions the building in real time. There is no performance penalty for oversizing the units. In fact, they work better as they are quieter, use less energy, and allow the owner to add additional zones without replacing the units for future expansion and can eliminate reheat coils.


  • 500:1 range/turndown at +/-3% accuracy
  • Eliminates GiGo
  • Self-balancing device
  • Technology can be applied to any damper device
  • Repeatable
  • Scalable
  • Modular
  • Economical

Our air valves undergo various tests at our lab, including:

  • Airflow verification testing
  • Repeatability testing
  • Minimum pressure drop testing
  • Multiple pressure testing
  • Variable elimination testing
  • Customized testing

Contact Us

Want to learn more about our patented variable orifice plate technology? Give us a call.