Refrigerant

Refrigerant is the working fluid inside a chiller's vapor-compression cycle — the substance that absorbs heat from the building's chilled-water loop and releases it to the outdoor environment (or to a cooling tower) by changing phase from liquid to gas and back. Different refrigerants have different operating pressures, efficiency curves, and environmental profiles, and the choice of refrigerant is a major factor in both equipment cost and long-term operating economics.

The refrigerant landscape changed dramatically over the past decade due to environmental regulation. R-22, the dominant refrigerant in commercial chillers from the 1980s through the mid-2000s, was phased out under the Montreal Protocol due to ozone-depletion concerns; virgin R-22 production ended in 2020 and recycled R-22 is now expensive and increasingly scarce. R-134a, R-1234ze, R-513A, and R-32 are the common replacements, each with different efficiency profiles and Global Warming Potential (GWP) ratings.

For replacement and retrofit financing, the refrigerant question matters in two ways. First, EPA 608 certification is required for any technician working with refrigerant — the cost shows up in your removal and disposal line item. Second, jurisdictions with restrictive refrigerant regulations (California's SB 1383, the EU F-Gas Regulation, etc.) may push you toward lower-GWP refrigerants that command a price premium but reduce regulatory risk over the unit's 15-to-20-year life. Factor both into the budget.