This HVAC document provides notes on pipe diameters, pipe types, and control cabling. The document specifies that the gas/suction pipe diameter is 12.7 and the liquid/refrigerant pipe diameter is 6.4. Semi-hard pipes run from the outdoor unit to refrigerant connections, while soft pipes run from units to connections. Control cabling is the electrical cable connecting the outdoor unit and all indoor units in a continuous loop.

1. HVAC Notes:
1 : 12.7/6.4
12.7 --- Denotes the diameter of the Gas/Suction Pipe.
6.4 --- Denotes the diameter of the Liquid/Refrigerant Pipe.
2 : Semi Hard Pipes --- From ODU to the refnets
Soft Pipes ----- From Unit to refnets
3 : Control Cabiling
It is the electrical cable from ODU and connecting all the units indoor (The wire length is
taken continuous i.e a loop of wire)