I've found if your recommendation includes challenging the Big Mistake often seen with a demand-controlled ventilation (DCV) sequence for air-handing units (AHUs), you better be prepared for some unexpected arguments.
Demand Controlled Ventilation (DCV) is a control strategy which aims to vary the amount of ventilation air a system provides a space based on the real-time ventilation requirements (i.e. the ventilation demand) of the space.
Bypass pipes, accompanied by a three-way control valve, are often seen in hydronic systems at both served loads (e.g., reheat coils) as well as at primary equipment (e.g., cooling towers).
These six case studies, covering just the last three years, illustrate how bad second-order effects can get when there are problems with the bypass pipe’s balancing valve.
April’s column kicked off a series that dove deep into the concept of building automation system (BAS) alarms. That series was supposed to end last month, but in the process of writing those articles, I realized I have more to say on the topic. So here is my victory lap!