Mimicking the changing temperatures outside, a facility’s HVAC system needs vary throughout the year, which could mean wasted energy if the system does not adjust. Variable air volume HVAC systems are one way to combat energy loss, but if you’re not employing a static pressure reset strategy, you may be missing a big opportunity to reduce energy levels even more.
What is a static pressure reset strategy?
A static pressure reset strategy is a tactic that can be applied to a variable air volume (VAV) HVAC system. Essentially, a VAV system varies the rate of air flow to different zones of a building to maintain the desired temperature. To ensure the delivery of the necessary air flow rate, the static pressure within the air duct is continuously monitored and maintained. The recommended static pressure, or set point, for a system is based on design conditions and is often too high for the actual needs of the facility. Direct digital control (DDC) systems can be used to implement a static pressure reset strategy, which involves systematically lowering the static pressure set point to better match actual operating conditions and increase system efficiency.
How does a static pressure reset strategy help you save?
Direct savings can be found in reducing the horsepower of the fans in the system to push air through the system. Indirect savings can include the elimination of reheat, over-cooling of interior spaces and the use of personal heaters. Although savings will depend on each building’s unique operations, savings can be significant.
Tips, tricks and considerations
A static pressure reset strategy is a good option in facility where building load varies based on occupancy, time of day and outside weather. Any weak links in the system need to be identified and repaired or replaced before this strategy is adopted to ensure its impact is sustainable.