Description:

What Is This Measure?

The wireless pneumatic thermostat (WPT) is a new technology that can be retrofitted to an existing pneumatic control system. WPTs give conventional pneumatic controls the energy-conserving functionality of more contemporary control systems, such as direct digital controls (DDC), but at a fraction of the cost. Payback was as low as two years, using only the most basic occupied/unoccupied control strategy. If other strategies were implemented, the potential for energy savings and financial viability would be greater.

WPT represents an economically viable technology that can reduce HVAC energy consumption, resulting in lower energy costs across a wide variety of office types and climate zones. It should be considered for any facility that currently uses conventional pneumatic controls with their HVAC system.

Special Considerations

It is advisable to perform pre-installation tests to determine how well wireless signals can be transmitted within a building where a WPT retrofit is being considered.

Planning for a WPT occupied/unoccupied control strategy should take into account the possibility of reduced energy savings in areas where high thermal mass stabilizes temperature over longer periods of time. During the WPT assessment, some interior areas within the concrete-and-steel Wilson Center did not demonstrate temperature changes normally associated with an occupied/unoccupied schedule, though other indicators suggested that such a schedule was in effect. After exploration of the issue, it was determined that the high thermal mass of the interior spaces was slowing temperature changes that were occurring more rapidly in the building’s exterior spaces.

See GSA’s Green Proving Ground for more details on the field demonstration findings.