What is hydronic pipingin construction?

Chilled water runs cold, commonly around 44 degrees F supply, from the chiller to the cooling coils and back, and it must be insulated with a continuous vapor barrier or it sweats and stains ceilings. Condenser water runs warmer, between the chiller and the cooling tower, and is often left uninsulated indoors. Same pipe materials, very different insulation lines on the estimate, so keep the services separated in the takeoff.

US commercial work typically uses Schedule 40 black steel on larger sizes, joined by welding or grooved mechanical couplings, and Type L copper or press-fit systems on smaller branch sizes. Some specs allow PEX or other plastics in limited services. The joining method matters as much as the material for labor cost, since a welded joint, a grooved coupling, and a press connection carry very different installation times.

Valves and specialties (isolation, balancing, check valves, strainers, air vents) are counted each off the plans and flow diagram, because they are priced items the supplier will quote. Fittings on plant room work are usually counted individually since they dominate the labor there; on long distribution runs many estimators carry a percentage allowance instead. Hangers follow the pipe at the spacing the specs require, priced into the per-lf labor or as a separate count.