由于减少了空间和材料需求，节省了成本，高压高速风管系统越来越受欢迎。紧凑型风管系统在多层建筑中具有特殊优势。每平方英尺的建筑成本很高，这使得减少空气分配系统所需的空间成为当务之急。但是使用紧凑的高速系统会导致噪音问题。这反过来又引起了人们对使用管道衬垫来吸收不需要的声音的兴趣。基于噪音考虑，当“能源危机”使得管道系统的隔热非常理想时，已经开发出了相当重要的管道内衬。现在，风管内衬的联合使用控制了噪音，减少了能量损失，从而创造了一个蓬勃发展的风管内衬市场。使用隔热和/或隔音材料作为风管内衬是绝对必要的- 时间长得很快。设计数据，尤其是摩擦损失数据几乎不存在。风管系统的设计者在内阻方面的数据非常有限。（见图1。）随着衬垫类型和制造方法的增加，设计问题变得更加混乱。1972年的ASHRAE基础知识手册[1]在第469页指出:目前关于纤维玻璃管道或内衬声学材料的管道的摩擦损失的信息很少。关于玻璃纤维管道中的摩擦损失，请参考制造商公布的数据。“制造商I关于摩擦损失的数据相当零散。一些制造商提供大量数据，而其他制造商则不提供，可用数据的可靠性和一致性尚不清楚。似乎每个制造商都可以使用自己的测试方法，因为没有全行业的标准方法可用。 这种情况促使ASHRAE的技术委员会TC5。2.风管设计，启动风管内部流量损失的研究。这项研究被命名为ASHRAE RP-176，即当用作风道内衬时，由于隔热和/或隔音材料的摩擦而产生的能量损失。建立了测定直管矩形管道与各种类型的玻璃纤维内衬接触时的压降特性的方法。本文总结了这项研究的结果。引文:新墨西哥州阿尔伯克基市阿什雷学报第84卷第2部分

High pressure, high velocity duct systems have been gaining in popularity due to cost savings resulting from reduced space and material requirements. Compact duct systems hold particular advantage for use in multi-story buildings. The high construction cost on a per sq ft basis put a premium on reducing the space needed for air distribution systems. But use of compact, high velocity systems led to noise problems. This in turn generated interest in and use of duct liners to absorb the unwanted sound. Rather significant use of duct liners, based on noise considerations, had already developed when the "energy crisis" made the thermal insulation of duct systems highly desirable. Now the combined use of duct liners to control noise and to reduce energy loss has generated a booming duct 1iner market. The use of thermal and/or acoustical insulations as air duct liners is at an all-time high and growing rapidly. Design data, and in particular friction loss data, were nearly nonexistent. The designer of duct systems had very meager data on 1iner resistance. (See Fig. 1.) As the number of liner types and methods of manufacture grew, the design problem became more confusing. The 1972 ASHRAE Handbook of Fundamentals [1] states on page 469: Presently there is little information on friction loss in fibrous glass ducts or ducts lined with acoustical material. Refer to manufacturer's published data for friction loss in fibrous glass ducts."Manufacturers I data on friction loss is rather spotty. Some manufacturers supply extensive data while others supply none, and the reliability and consistency of the available data is unknown. It appears that each manufacturer may use their own test method as no industrywide standard method is available.This situation prompted ASHRAE' s Technical Committee TC5.2, Duct Design, to initiate a research study on duct 1iner flow losses. The study was designated ASHRAE RP-176, Energy Loss Due to Friction of Thermal and/or Acoustical Insulations When Used as Air Duct Liners. It was established to determine the pressu~e drop characteristics of straight rectangular ducts when 1ined with various types of fiber glass liner. This paper summarizes the results of that study.