MIL-HDBK-411B VOL III

Abstract

Volume III of this three-volume handbook is a reference for the planning and engineering of environmental control systems for fixed Department of Defense (DoD) communications, data processing, and information systems facilities. The engineering concepts contained herein should be selectively applied to the environmental control elements of DoD fixed facilities. DoD communications and data processing installations include equipment rooms and spaces needing more precisely controlled environments than comfort spaces. The more limiting parameters within these rooms and spaces are established specifically for the equipment being used. Outside these specially designed areas, where personal computers (PCs) and other electronic office equipment are used, the environment is the responsibility of the user. Volume II should be used to ensure that power protection or conditioning for this equipment follows guidance provided therein. Volume I addresses these subjects in general terms for the planner, manager, or executive. Volume II addresses power system engineering considerations. Volume III addresses environmental control system engineering considerations. <br>Volume III applies to and discusses the following topics: <br>a. Matching types of building construction and environmental control systems to the local geographical, terrain, and weather features. <br>b. Characteristics and operation of environmental control system equipment. <br>c. Special types of construction and materials used to support and protect communications and data processing rooms and spaces. <br>d. Indoor atmospheric conditions required for communications and data processing equipment. <br>e. Identification of the types of environmental control systems and equipment best suited for use in communications and data processing facilities. <br>f. Methods of monitoring, controlling, and recording of environmental control system performance. <br>g. Energy conservation considerations. <br>h. Protection of the environment. <br>This handbook is intended to assist in selecting and planning environmental control systems to be installed or upgraded at DoD communications-electronics facilities and computer-based facilities. It is applicable to the engineering effort during initial establishment of a facility, or during upgrade of an existing facility. This handbook introduces practices and procedures that should be considered during the engineering design The guidance is not to be interpreted as directing that any or all of these control systems be employed at any given facility. Further, it is not to be used solely as a justification for retrofit of existing DoD communications, data processing, and information systems facilities. <br>Occupational Safety and Health Administration (OSHA) regulations require a safe work place at all times. Although OSHA does not approve specific tools or products, there are Federal specifications for safety tools and they are listed in the appropriate Qualified Products Lists (QPLs). <br>OSHA regulations state that employees shall not be required to work in surroundings or under working conditions which are unsanitary, hazardous, or dangerous to their health and safety. Employers are required to initiate and maintain programs which comply with this requirement. These programs include inspections of job sites, materials, and equipment. They also ascertain that use and operation of equipment or machinery is by qualified employees. <br>The National Institute of Occupational Safety and Health (NIOSH) estimates that millions of workers may be exposed to hazards in confined spaces each year. Investigation of confined space injuries and fatalities indicates that workers generally do not recognize they are working in a confined space with unforeseen hazards. These studies show that testing and monitoring of the atmosphere are often not performed, and that rescue procedures are seldom planned. <br>NIOSH'S definition of a confined space is "a space which by design has limited openings for entry and exit; unfavorable natural ventilation which could contain or produce dangerous air contaminants, and which is not intended for continuous employee occupancy." <br>Safety procedures should be established for electronic equipment employing high voltages or radiating high-energy fields. Safety requirements have been established in individual military department documents that should be reviewed prior to designing systems in accordance with guidance contained herein. <br>Remember these four rules: <br>a. Ground everything that might accidentally become energized. <br>b. Keep electricity separated from materials that are not to be electrified. <br>c. Keep heat and sparks (from electrical conductors and equipment) from starting a fire or triggering an explosion. <br>d. Do not assume safety: electrical equipment is dangerous until made or proven safe. <b><u>Intended Use:</u></b> The purpose of this handbook is to provide basic guidance to managers and engineers of the military departments and agencies in the design and installation of environmental control systems at DoD fixed-communications and related automatic data-processing facilities. The subject matter included in the text is intended to make the designer and manager of a communications or data processing facility better able to interface with HVAC designers and providers. <br>