Accutrol AccuValve: Low Pressure Drop by Design

One of the biggest opportunities to reduce energy costs in laboratories, healthcare facilities, and life science buildings is hiding inside the ductwork: the airflow control valve.

What Is Pressure Drop — And Why Does It Matter?

In any ventilation system, air is pushed through ductwork by a fan. As that air moves through components like valves, dampers, and fittings, it encounters resistance. That resistance is called pressure drop, measured in inches of water column ("wc). The higher the pressure drop across a component, the harder the fan has to work to push air through it.

Think of it like driving with the parking brake on. The car still moves, but the engine works much harder than it needs to, burning more fuel in the process. In a ventilation system, that "extra fuel" is electricity. Every component that adds unnecessary resistance forces the fan to consume more horsepower, more kilowatt-hours, and more money. In critical environments where ventilation runs continuously, 24 hours a day, 365 days a year, that adds up fast.

The Hidden Cost of High Pressure Drop Systems

For decades, the most commonly used airflow control valves in critical environments were venturi valves. These valves rely on a high static pressure to operate reliably, typically requiring system pressures of 1.0" wc or more, per valve. While they became an industry standard, their high pressure drop requirement carries real consequences.

A system running at unnecessarily high static pressure requires substantially more fan horsepower, and in a building where fans run around the clock, that means tens of thousands of dollars in wasted energy every year. High static pressure systems are also louder, making buildings unpleasant for occupants. And because many high pressure drop valves lack true airflow measurement capability, problems like blocked valves or closed dampers can go undetected, quietly compromising air quality and safety.

How Airflow Control Valves Are Designed Makes All the Difference

Not all airflow control valves are created equal. The pressure drop across a valve is largely determined by its internal design, and a smarter design can dramatically reduce resistance without sacrificing accuracy or reliability.

Accutrol's AccuValve was built from the ground up with one priority: minimize pressure drop. The inspiration came from the design of a duct silencer. A silencer reduces the available airflow area in a duct by roughly 50%, yet its pressure drop is surprisingly low because of the airfoil shape of its internal baffles. An airfoil creates very little drag relative to its size, and the AccuValve applies this same principle internally. The valve uses an airfoil-shaped compression section to produce smoother, more laminar flow, and a static pressure regain section downstream to recover energy from the airstream. The result is the lowest pressure drop of any critical environments airflow control valve on the market. And because the AccuValve includes continuous airflow measurement, it immediately alarms if anything goes wrong: blocked valves, closed dampers, and obstructions are detected instantly.

Real-World Results: University of St. Thomas

Owens Science Hall at the University of St. Thomas in St. Paul, Minnesota was constructed in 1996 with 90 fume hoods served by 217 venturi airflow control valves. By 2012, persistent pressure problems had developed. Only 37% of rooms were maintaining the negative static pressure required for safe laboratory operation.

The university replaced the entire system with Accutrol's AccuValve in a phased, three-year project. The new valves had to operate reliably at the existing high static pressure of -5.0" wc during the transition, then continue performing at the final set-point of -1.0" wc once complete, a pressure range no other valve on the market could handle.

The results exceeded expectations. Exhaust fan horsepower was cut by more than half. Room sound levels dropped enough that professors could deliver lectures with fume hoods fully open, something previously impossible. Annual energy savings came in at over $75,000, and the energy utility provided an additional $73,000 in rebates.

"The replacement of the venturi valve system with the low pressure drop AccuValve system has proven to save the university money by significantly lowering our monthly utility bill." - David Clysdale, St. Thomas Facility Manager

Conclusion

The pressure drop across an airflow control valve plays out on every utility bill for the life of a building. Over a 20-year system life, the difference between a high and low pressure drop valve can exceed $400,000 in combined supply and exhaust savings. For building owners, the message is simple: ask about pressure drop early, and make sure the answer is low. For engineers and contractors, valve selection is one of the highest-leverage decisions in a ventilation system design. And low pressure drop, paired with true airflow measurement, delivers value that extends well beyond the mechanical room.