Specifications include, but are not limited to: Annual Chiller Maintenance at various locations around Iowa State University; Equipment Covered 3.2.1 Main Campus Plant 3.2.1.1 Chiller #1 – Chiller #1 is a Carrier model 17DA steam turbine driven centrifugal chiller rated at 5,000 tons. This chiller was installed in 1968 and was converted from R-12 to R-134a refrigerant in 1995. 3.2.1.2 Chiller #2 – Chiller #2 is a Carrier model 17DA steam turbine driven centrifugal chiller rated at 5,000 tons. This chiller was installed in 1978 and was converted from R-12 to R-134a refrigerant in 1995. 3.2.1.3 Chiller #3 – Chiller #3 is a York model OM steam turbine driven centrifugal chiller rated at 5,000 tons. This chiller was installed in 1984 and uses R-22 as a refrigerant. 3.2.1.4 Chiller #4 – Chiller #4 is a York model YK motor driven centrifugal chiller rated at 2,000 tons. This chiller was installed in 1997 and uses R-134a as a refrigerant.