223.0 – U –

UMC. [HCD 1, HCD 2, OSHPD 1, 1R, 2, 3, 4 & 5] The most recent edition of Uniform Mechanical Code published by the International Association of Plumbing and Mechanical Officials. Unit Heater. A heating appliance designed for nonresidential space heating and equipped with an integral means for circulation of air. Unusually Tight Construction. Construction where: (1) Walls and ceilings exposed to the outdoors have a con tinuous water vapor retarder with a rating of 1 perm or less with openings gasketed or sealed. (2) Weatherstripping is on openable windows and doors. (3) Caulking or sealants are applied to areas such as joints

around window and door frames, between sole plates and floors, between wall-ceiling joints, between wall panels, and at penetrations for plumbing, electrical, and gas lines and at other openings. Use (Material). The placing in action or making available for service by opening or connecting a container utilized for confinement of material, whether a solid, liquid, or gas.