ASHRAE standard 90.1’s goal to progressively reduce building energy usage has resulted in the steady introduction of additional requirements to each new version of the standard. In more recent versions, added requirements for the use of DDC controls along with the use of control sequences such as economizers (air and waterside, and most recently, with “self-diagnostic” capabilities), optimum start, demand-controlled ventilation, reset of duct/pipe pressure setpoints for variable volume systems, single-zone AHUs, and the fan-powered sections of VAV boxes can no longer be constant volume, etc.
However, through the 2013 version, these have essentially applied to only “new” construction. Further, many of these “sequence” requirements have started to become standard practice for building design and construction. Therefore, the effect on the controls market has been minimal (or even for the worst given its possible negative effect on controls contractor’s profit margins).