Hydronic Systems
CSI Division 23, HVAC
Heating or cooling systems that move water or a water-glycol mixture through piping using pump pressure to transfer heat, as distinct from a gravity-fed plumbing system that simply relies on elevation to move water.
Why it matters
Hydronic systems show up throughout a building's mechanical systems, from boilers and radiators to the chilled water loops that feed large HVAC equipment, and they require their own design considerations, pump sizing, pipe sizing for flow rate, that are different from the considerations a gravity-fed domestic water system needs.
On a real project
A building's heating system circulates hot water from a boiler through a closed hydronic loop, using a pump to push the water through radiators throughout the building and back to the boiler, rather than relying on gravity to move the water anywhere.
Who this matters most to
A Pipefitter installs the pressurized piping a hydronic system depends on, distinct from the gravity-fed piping a plumber typically installs for domestic water and drainage.
Where this goes wrong
A hydronic system is piped with fittings and pipe sizing appropriate for a gravity-fed system instead of one designed for pump pressure, creating excessive flow resistance in the loop. The system struggles to circulate enough water to heat the building evenly, and the pump has to work harder than it should.