Mark Rockwood (PE, QCxP, LEED AP), a Senior Engineer II – Controls and Commissioning in Elara Engineering’s Building Performance Group, recently published his second article in the Spring 2026 issue of Chicagoland Buildings & Environments entitled “Dual Temperature Systems / 2-PIPE vs. 4-PIPE: What They Are, Challenges, and Optimization Opportunities.”
Dual temperature systems are common in large buildings to circulate either hot or chilled water for heating and cooling of spaces throughout a building. Although dual temperature systems effectively transport energy through liquid medium while using a minimal amount of space, these systems have their own unique benefits and drawbacks.
It is important for owners, property managers, and building maintenance staff to understand the limitations of dual temperature systems so that comfort expectations can be properly communicated to building occupants. Most notably, dual temperature systems can only be in hot water mode or chilled water mode at any given time and never both simultaneously. Due to the economics and practicality associated with dual temperature systems, it is anticipated that the use of dual temperature systems will continue far into the future, thus understanding how to leverage the strengths of these systems will continue to be paramount.
A reprint of Mark Rockwood’s article can be found here.
Mark Rockwood
Senior Engineer II – Controls and Commissioning
mrockwood@elaraeng.com
