In enclosed spaces, the combined treatment of the air to control, as specified, temperature, relative humidity, velocity of motion, and radiant heat energy level, with consideration of the need for removal of air-borne particles and contaminant gases.Heating Ventilating and Air conditioning (HVAC) System is capable of providing heating humidification during the winter, cooling and dehumidification during summer, the supply of fresh air through ? out the year and capability to furnish each of these services in a controlled manner and when sought by building occupants.Plumbing is a system of piping, apparatus, and fixtures for water distribution and waste disposal within a building. This chapter covers the basic water supply and water distribution systems, the theater of operations (TO) water supply and water distribution systems, and the sewerage system. Plumbing also includes the installation and maintenance of these systems. When architects design a building, they prepare a set of prints and a set of specification sheets detailing the types and quality of materials to be used. Plumbers use the prints and specifications to layout and plan the project.