tailieunhanh - HVAC Systems Design Handbook part 1

This chapter is devoted to ‘‘fundamental’’ fundamentals—certain principles which lay the foundation for what is to come. Starting with the original author’s suggested thought process for analyzing typical problems, the reader is then exposed to a buzzword of our time: value engineering. Next follows a discussion of codes and regulations, political criteria which constrain potential design solutions to the bounds of public health and welfare, and sometimes to special interest group sponsored legislation | Source HVAC Systems Design Handbook Chapter 1 HVAC Engineering Fundamentals Part 1 Introduction This chapter is devoted to fundamental fundamentals certain principles which lay the foundation for what is to come. Starting with the original author s suggested thought process for analyzing typical problems the reader is then exposed to a buzzword of our time value engineering. Next follows a discussion of codes and regulations political criteria which constrain potential design solutions to the bounds of public health and welfare and sometimes to special interest group sponsored legislation. The final sections of the chapter offer a brief review of the basic physics of heating ventilating and air conditioning HVAC design in discussions of fluid mechanics thermodynamics heat transfer and psychrometrics. Numerous classroom and design office experiences remind us of the value of continuous awareness of the physics of HVAC processes in the conduct of design work. Problem Solving Every HVAC design involves as a first step a problem-solving process usually with the objective of determining the most appropriate type of HVAC system for a specific application. It is helpful to think of the problem-solving process as a series of logical steps each of which must be performed in order to obtain the best results. Although there are various ways of defining the process the following sequence has been found useful 1. Define the objective. What is the end result desired For HVAC the objective usually is to provide an HVAC system which will control 1 Downloaded from Digital Engineering Library @ McGraw-Hill Copyright 2004 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use as given at the website. HVAC Engineering Fundamentals Part 1 2 Chapter One the environment within required parameters at a life-cycle cost compatible with the need. Keep in mind that the cost will relate to the needs of the process. More