Standard Test Method for Thermal Performance of Cooling-Air Duct Sections, Using a Calibrated Hot Box
|Publication Date:||26 October 1983|
1.1 This test method covers thermal performance testing of cooling-air duct sections under steady-state operating conditions. It provides for measurement of thermal transmittance with the duct interior confining a moving air stream.
NOTE 1--This test method is distinct from Test Methods C 177, C 335, and C 518, which do not deal with thermal performance in the presence of a ducted air stream.
1.1.1 This test method is specific to testing air-handling ducts for space cooling, but can be adapted for any closed duct, pipe, or channel transporting chilled gas or liquid.
1.1.2 This test method is intended primarily for measuring the steady-state thermal transmittance of insulated cooling-air ducts, but it may also be used to test uninsulated ducts when a comparison between insulated and uninsulated air ducts under dynamic conditions is desired.
1.1.3 Various units (for thermal properties) may be found in the literature. The values stated in SI units are to be regarded as the standard in this test method. Conversion factors to the inch-pound and kilogram-calorie systems are shown in Table 1.
1.2 The general principles outlined in this test method must be followed. As long as these general principles are satisfied, however, the details of the apparatus may be varied to meet the needs of the individual operator.
1.3 In a test method as complex as this one, it is impractical to include sufficient details so that the test method could be used by a person not technically trained. Therefore, those applying the test method shall be trained in methods of temperature measurement, shall know the theory of heat flow, and shall understand general testing practices. In standardizing this test method, it would be unwise to restrict unnecessarily the initiative of researchers who may wish to develop and improve the test method. Accordingly, in Section 6, the essential principles and the general arrangement of the apparatus are given first; to comply with this test method, any test must satisfy these general requirements. The details of the apparatus and the suggested test procedure that follow are not given as mandatory requirements, but as examples that satisfy the general principles. Because of the variety of duct systems and operating conditions, it would be a mistake to confine all measurements to a single experimental arrangement.
1.4 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.