Knowing what a two-pipe system is and how to properly maintain it is critical as we transition from the heating season to the cooling season. At First Point Mechanical, we have a great deal of first-hand experience working with buildings that have two-pipe systems.
Two-pipe systems are systems that share the same piping, but can only supply heating or cooling at one time. A two-pipe system contains supply and return piping throughout the building and utilizes a series of valves that allow for only heating or only cooling water to be supplied, depending on the season.
These types of systems require planned shutdowns and switchovers, usually around May 1-15 and again around September 1-15.
At the time these switchovers are performed, it may be necessary to drain the glycol from the heating systems and store for the cooling season. The same may be true during the fall switch over.
During this time, it is also recommended to perform cooling operations start-up on chillers as well as pumps serving these systems.