One aspect of the invention provides a composite refrigeration line set including: a suction line and a return line. One or more of the lines are a composite refrigeration line set tube including: an inner plastic tube; a first adhesive layer external to the inner plastic tube; an aluminum layer surrounding the first adhesive layer and coupled to the inner plastic tube via the first adhesive layer; a second adhesive layer external to the aluminum layer; and an outer plastic layer surrounding the aluminum layer and coupled to the aluminum layer via the second adhesive layer. The outer plastic tube includes a flame-resistant compound combined with PERT. The composite refrigeration line set tube has a flame and smoke spread rating of no more than 25/50 when tested in isolation using Appendix A1.22 of the CAN/ULC-S102-10 Standard Test Method for Surface Burning Characteristics of Building Materials and Assemblies.