Heating, Ventilating, Air Conditioning, and Refrigerating Engineering. Introduction. The modern day definition of air conditioning was created in the early 2. I/916FYTIHmvL._SX522_.jpg' alt='Control Edition Engineering International System Of Units' title='Control Edition Engineering International System Of Units' />Hermann Rietschel, Alfred Wolff, Stuart Cramer, and Willis Carrier. Cramer, a textile engineer in North Carolina, is credited with coining the phrase air conditioning in 1. In 1. 90. 8, G. B. Wilson developed the first holistic definition of what air conditioning encompasses. The Original Definition of Air Conditioning. To maintain a suitable degree of humidity in all seasons and in all parts of a building. E Prime 2 0 Keygen Generator. To free the air from excessive humidity during certain seasons. To supply a constant and adequate supply of ventilation. To efficiently wash and free the air from all micro organisms, effluvias, dust, soot, and other foreign bodies. To efficiently cool the air of the rooms during certain seasons. To either heat the rooms in winter or to help heat them. Managing Enclosure Heat Flows While the control of moisture is practically a universal requirement for buildings, the importance of the control of heat transfer tends. To combine all the above desiderata in an apparatus that will not be commercially prohibitive in first cost or cost of maintenanceSource Nagengast, B., 1. Early Twentieth Century Air Conditioning Engineering, ASHRAE Journal, March p. Though he did not actually invent air conditioning nor did he take the first documented scientific approach to applying it, Willis Carrier is credited with integrating the scientific method, engineering, and business of this developing technology and creating the industry we know today as air conditioning. Description. Todays HVAC R engineer, or mechanical engineer of record MER, continues to be a steward of the basic discipline issues identified by Mr. Wilson nearly 1. 00 years ago. Roles have expanded, though, to address more modern quality of life issues. ASHRAE offers the current vision of the MERs stewardship responsibilities to improve the quality of life by helping keep indoor environments comfortable and productive by helping to deliver healthy food to consumers and by helping to preserve the outdoor environment. As part of a holistic controlled environment design solution, the MER is responsible for addressing seven major processes. These are Heatingthe addition of thermal energy to maintain space or process conditions in response to thermal heat loss. Coolingthe removal of thermal energy to maintain space or process conditions in response to thermal heat gain. Humidifyingthe addition of water vapor to maintain space or process moisture content. Dehumidifyingthe removal of water vapor to maintain space or process moisture content. Cleaningthe process of removing particulate and bio contaminants from the conditioned space. Ventilatingthe process of providing suitable quantities of fresh outside air for maintaining air quality and building pressurization. Effectivenessthe process of achieving the desired thermal energy transfer, humidity control, filtration, and delivery of ventilation air to the breathing zone of the occupied space in accordance with required needs. The 15th edition of Gieseckes Technical Drawing and Engineering Graphics is a comprehensive introduction and detailed reference for creating 3D models and 2D. It is important for the MER to be involved early in the project, even as early as the programming stage, so that mechanical system space issues and facility energy budgets can be evaluated and integrated into the design process before building construction elements, configurations, and orientations are finalized see also WBDG High Performance HVAC. A few critical issues that need to be considered early are Financial Focus Will the project be a code minimum type facility or will total ownership cost perspectives be considered that balance capital first costs against long term ownership and operating costs Owner Sophistication The MER needs to understand the abilities of the owner and keep these in mind as mechanical system architecture issues are considered. The best of design solutions arent much good if operators do not understand how to correctly operate or control the equipment. Operations and Maintenance No matter what level of system complexity is applied, it is imperative that suitable space be made available for equipment without compromising performance or maintenance access. A good MER will understand the requirements published in equipment installation manuals and focus on providing prescribed minimum service and operating considerations in the planning of a facility layout. Before any equipment selections can be finalized, the MER will need to perform a thermal load calculation for the developing facility based on internal and external influencing factors. In many cases, this activity will be expanded to include analysis of comprehensive energy models. These models will foster dynamic integration opportunities whereby the design team and owner can evaluate the impacts of trade offs between facility construction elements, mechanical system alternatives, and available operating efficiencies. Load calculations can be utilized for any or all of the following design activities Defining the basic load dynamics. Evaluating solution alternatives via life cycle analysis. Introduction. Standard. Traffic control devices shall be defined as all signs, signals, markings and other devices used to regulate, warn or guide traffic placed on. Control Edition Engineering International System Of Units' title='Control Edition Engineering International System Of Units' />Optimizing system performance. Selecting final HVAC equipment. Establishing energy budgets for owners. Verification of proposed equipment performance. Commissioning Design Intent for seasonal comparison. The MER will be responsible for securingdeveloping the following fundamental information from the Owner and design team members Basic Load Calculations Establish summerwinter design weather conditions paying particularly close attention to regional weather issues and impact on humidificationdehumidification considerations. All elements of the building envelope must be identified so that thermal energy lossgain can be determined. Reference should be made to ASHRAE Standard 9. Orientation of walls and roofs need to be defined so that sun angle impacts can be evaluated. The composite construction of all walls, roofs, and floors needs to be defined so that thermal transfer calculations can be performed. This information will also be useful when a dew point analysis is performed on the envelope. Thermal mass and color of walls and roofs need to be defined so that thermal time lags and radiation absorption can be evaluated. Fenestration U values and solar heat gain coefficients need to be defined. Externalinternal shading provisions need to be defined that may impact fenestration heat gain. Lighting. Lighting densities and ballast loss factors need to be mapped per individual space. Maximum densities are identified for individual space types in ASHRAE Standard 9. Opportunities to capture natural light Daylighting and apply occupancy sensing techniques to reduce light heat gain need to be explored. Basic internal sensible heat gain allowances for receptacle loads need to be established. Miscellaneous sensible and latent heat gain values need to be identified for special circumstances. People contributions. The total number of people and the occupancy usage profiles need to be established. The activity levels of people need to be identified. Ventilation. For a given space, the area factor and people factor ventilation rate components need to be calculated per ASHRAE Standard 6. Depending on HVAC system architecture employed, critical space calculations may need to be performed to adjust ventilation quantities to ensure adequate outside air is being provided to occupied spaces during all system fluctuations. Calculate all building exhaust requirements and compare to minimum required outside air ventilation rates. The overall impact of building pressurization dynamics must be evaluated for the facility, for seasonal conditions, and for regional locations. The MER must fully understand how moisture and thermal gradients work with the building envelope construction and what influence infiltrationexfiltration has on condensation potential. Basic system zoning. Identify spaces and zones. Establish summerwinter design temperature set point conditions and dead band ranges per thermal comfort recommendations of ASHRAE Standard 5.