Variable refrigerant flow (VRF) systems were first introduced to the HVAC community in Japan in 1980 as a highly efficient heating and cooling option in multi-zone comfort applications. It took the ...

Back in 1983 — over three decades ago — a built-up DX cooling system was a good alternative to a chilled water-based system for the Molina Center (Long Beach, CA). The 460,000-sq-ft office complex is ...