1.1 该试验方法确立了热箱设备的设计原则，以及在受控实验室条件下测定建筑组件稳态热性能的最低要求。该方法也用于在标准化测试条件下测量建筑材料的热性能，如材料规范中要求的测试条件 C739 , C764 , C1224 和实践 C1373 . 1.2 该试验方法适用于大型均质或非均质试样。 本试验方法适用于建筑结构或建筑材料的复合组件，对于这些结构或复合组件，可以构建适合试验装置的代表性试样。试样凸起或凹陷的尺寸由热箱设备的设计控制。一些热箱仅限于平面或近似平面的试样。然而，更大的热盒已被用于表征投影天窗和阁楼部分。看见 3.2 用于试样的定义和该方法特有的其他术语。 注1: 此测试方法取代了“测试方法” C236 ，保护热盒，以及 C976 ，已撤回的校准热盒。先前根据试验方法设计和操作的试验装置 C236 和 C976 将需要对校准和操作程序进行轻微修改，以满足测试方法的要求 C1363 . 2. 1.3 设计和操作得当的热箱设备与试验方法直接相似 C177 防护热板，用于测试暴露在空气引起的温差下的大型试样。 热箱设备的操作需要对温度、面积和功率进行大量的基本测量。进行这些测量的设备需要进行校准，以确保数据准确无误。在初始设置和定期验证测试期间，每个测量系统和传感器都根据可追溯到国家标准实验室的标准进行校准。如果热箱设备已经以理想的方式设计、构造和操作，则不需要进一步的校准或调整。 因此，热箱被认为是一种主要方法，通过直接评估测量中使用的仪器的部件测量不确定度来分析结果的不确定度。 1.3.1 在均质材料的理想热箱试验中，无论是热试件表面还是冷试件表面都没有温差来驱动侧面热流。此外，将不存在将驱动热量穿过计量室壁的边界的温差。然而，经验已经证明，保持完美的保护/计量室平衡是不可能的，并且需要小的校正来准确地表征来自计量室的所有热流路径。 为了获得测试结果的最终置信度，有必要通过对具有已知传热值的试样进行测量并将这些结果与预期值进行比较，来对热箱设备的总体结果进行基准测试。 1.3.2 基准试件是热性能均匀且可预测的均质面板。这些面板或面板的代表性部分在其他设备上测量了它们的热性能，这些设备可以直接追踪，或者与国家标准实验室进行了良好的比较。 例如，测试方法 C177 热板，一种测试方法 C518 热量计或其他测试方法 C1363 热箱将提供足够的样本。注意测试方法的使用 C518 或类似的装置会产生额外的不确定性，因为这些装置是使用转移标准或标准参考材料校准的。通过执行该基准测试过程，热箱操作员能够开发额外的方程，该方程预测通过试样的净热流的修正量，该修正量考虑了任何热箱壁损失和侧面损失。 这种基准测试提供了很大的信心，即任何额外的热流都可以被消除或以足够的精度量化，从而成为总体不确定性的一个次要因素。 1.4 为了确保结果的不确定性达到可接受的水平，使用该测试方法的人员必须具备热测量和测试实践的要求以及与隔热材料和系统相关的传热理论的实际应用的知识。应为每个设备提供详细的操作程序，包括设计原理图和电气图纸，以确保测试符合该测试方法。 1.5 本试验方法适用于正常建筑应用的典型条件。温带自然发生的室外温度范围约为−48至85°C，住宅内部的正常温度约为21°C。如有必要，应根据材料的特性及其潜在可变性，对用于构建试样的建筑材料进行预处理。预处理参数的选择应准确反映预期使用的试样，并应记录在报告中。 实践 C870 可以用作试样调节的指南。热箱法的一般原理可用于构建测量在高温下通过工业系统的热流的设备。这种类型的设备的详细设计超出了该方法的范围。 1.6 该试验方法允许在试样表面的自然或强制对流条件下进行操作。强制对流条件下的气流运动方向应垂直或平行于表面。 1.7 热箱设备还用于测量小于测量面积的单个建筑组件。这些测试需要特殊的表征程序。这些情况的一般测试程序如所述 附件A11 . 1.8 窗户系统（窗户、门、天窗、幕墙等）热测试的具体程序如测试方法所述 C1199 和实践 E1423 . 1.9 热箱已被用于研究非均质建筑组件的热行为，如结构构件、管道、电源插座或结构缺陷（如绝缘空隙）。 1.10 本试验方法规定了构造和操作令人满意的热箱设备所需的一般设计要求，并涵盖了各种设备构造、试验条件和操作条件。未给出符合本标准的详细设计，但必须在一般要求的限制范围内进行开发。参考文献中给出了热箱设备的设计、构造、表征和操作中使用的分析工具、概念和程序的示例 ( 1. 34 ) . 3. 1.11 当构造成测量水平方向上的热传递时，热箱设备用于测试墙壁和其他垂直结构。当建造用于测量垂直方向上的热传递时，热箱用于测试屋顶、天花板、地板和其他水平结构。其他方向也是允许的。相同的装置可以在几个方向上使用，但可能需要特殊的设计能力以允许重新定位到每个方向。无论试验方向如何，应首先在已知热阻的样品就位的情况下，在该方向上验证仪器性能。 1.12 本试验方法未规定设备操作所需的所有细节。关于材料取样、试样选择、预处理、试样安装和定位、试验条件选择以及试验数据评估的决定应遵循适用的ASTM试验方法、指南、实践或产品规范或政府法规。如果不存在适用的标准，则必须使用反映公认传热原理的合理工程判断并形成文件。 1.13 此测试方法适用于稳定- 状态测试，并且没有建立进行动态测试或分析动态测试数据的程序或标准。然而，经过额外的表征，几个热箱设备已经在动态（非稳态）条件下运行 ( 1. ) 需要额外的表征，以确保在测试期间考虑到热流和储存的所有方面。动态控制策略包括周期性或非周期性温度循环，例如，遵循昼夜循环。 1.14 该试验方法不允许在测量过程中有意将空气或水分通过试样进行质量传递。空气渗透或水分迁移会改变净传热。复杂的相互作用和对许多变量的依赖，加上在这种条件下测试的经验有限，使得不建议在本标准中包括这种类型的测试。中给出了此类测试的进一步考虑因素 附录X1 . 1.15 本标准并不旨在解决与其使用相关的所有安全问题（如有）。 本标准的使用者有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 1.16 本国际标准是根据世界贸易组织技术性贸易壁垒委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认的标准化原则制定的。 ====意义和用途====== 5.1 需要在代表性测试条件下通过隔热结构的热传递的准确数据。需要这些数据来判断是否符合规范和条例，提供设计指导，对材料或结构变化的影响进行研究评估，以及验证或使用模拟模型。其他ASTM标准，如试验方法 C177 和 C518 提供以温控平板不透水板为界的均质试样的数据。热箱测试方法更适合为大型建筑构件提供此类数据，通常为- 上或复合性质，其两侧暴露于温度控制的空气中。 5.2 对于具有代表性的建筑施工结果，只应对具有代表性部分进行测试。试样应复制框架几何形状、材料组成和安装实践以及结构方向（见第节 7. ). 5.3 该测试方法不确定测试条件、样本配置或数据采集细节，而是让这些选择以与所考虑的特定应用一致的方式进行。 使用该试验方法获得的数据仅代表试验条件下的试样性能。试验条件不太可能在使用条件下完全重复，必须提醒试验结果的使用者注意可能存在的显著差异。例如，在一些试样中，特别是那些含有空腔或向一个表面开放的空腔的试样，其整体电阻或透射率将取决于由于内部对流而导致的试样上的温差。 5.4 在大型复杂结构使用热箱设备之前，应进行详细的热流分析。相邻表面之间包含空腔的结构，例如阁楼部分，包括带倾斜屋顶的天花板，可能很难正确测试。在设计试样时，必须考虑试样尺寸、自然空气运动、通风效应、辐射效应以及防护装置/仪表接口处挡板的影响。 5.5 对于具有显著影响热性能的空气空间的垂直试样，计量室尺寸应与有效结构高度相匹配。 如果无法做到这一点，则应在计量室边界处的样本空气腔内安装水平对流屏障，以防止计量区域和防护区域之间的空气交换。操作员应在报告中注明对流屏障的任何使用情况。该报告应包含一个警告，说明屏障的使用可能会改变通过系统的热传递，从而导致重大错误。对于低密度隔热的天花板试验，试样的最小横向尺寸应至少为预期对流电池尺寸的几倍。 5.6 由于该测试方法用于确定通过由计量箱划定的测试区域的总热流，因此，如果独立地确定通过剩余周围区域的平行热流，则可以确定通过小于测试区域的建筑元件（例如窗户或面板单元的代表区域）的热流。看见 附件A8 一般方法。 5.7 试验报告中应包括对试验期间使用的所有特殊条件的讨论（见第节 12 ).

1.1 This test method establishes the principles for the design of a hot box apparatus and the minimum requirements for the determination of the steady state thermal performance of building assemblies when exposed to controlled laboratory conditions. This method is also used to measure the thermal performance of a building material at standardized test conditions such as those required in material Specifications C739 , C764 , C1224 and Practice C1373 . 1.2 This test method is used for large homogeneous or non-homogeneous specimens. This test method applies to building structures or composite assemblies of building materials for which it is possible to build a representative specimen that fits the test apparatus. The dimensions of specimen projections or recesses are controlled by the design of the hot box apparatus. Some hot boxes are limited to planar or nearly planar specimens. However, larger hot boxes have been used to characterize projecting skylights and attic sections. See 3.2 for a definition of the test specimen and other terms specific to this method. Note 1: This test method replaces Test Methods C236 , the Guarded Hot Box, and C976 , the Calibrated Hot Box which have been withdrawn. Test apparatus designed and operated previously under Test Methods C236 and C976 will require slight modifications to the calibration and operational procedures to meet the requirements of Test Method C1363 . 2 1.3 A properly designed and operated hot box apparatus is directly analogous to the Test Method C177 guarded hot plate for testing large specimens exposed to air induced temperature differences. The operation of a hot box apparatus requires a significant number of fundamental measurements of temperatures, areas and power. The equipment performing these measurements requires calibration to ensure that the data are accurate. During initial setup and periodic verification testing, each measurement system and sensor is calibrated against a standard traceable to a national standards laboratory. If the hot box apparatus has been designed, constructed and operated in the ideal manner, no further calibration or adjustment would be necessary. As such, the hot box is considered a primary method and the uncertainty of the result is analyzed by direct evaluation of the component measurement uncertainties of the instrumentation used in making the measurements. 1.3.1 In an ideal hotbox test of a homogenous material there is no temperature difference on either the warm or cold specimen faces to drive a flanking heat flow. In addition, there would be no temperature differences that would drive heat across the boundary of the metering chamber walls. However, experience has demonstrated that maintaining a perfect guard/metering chamber balance is not possible and small corrections are needed to accurately characterize all the heat flow paths from the metering chamber. To gain this final confidence in the test result, it is necessary to benchmark the overall result of the hot box apparatus by performing measurements on specimens having known heat transfer values and comparing those results to the expected values. 1.3.2 The benchmarking specimens are homogeneous panels whose thermal properties are uniform and predictable. These panels, or representative sections of the panels, have had their thermal performance measured on other devices that are directly traceable or have been favorably compared to a national standards laboratory. For example, a Test Method C177 Hot Plate, a Test Method C518 Heat Meter or another Test Method C1363 Hot Box will provide adequate specimens. Note that the use of Test Method C518 or similar apparatus creates additional uncertainty since those devices are calibrated using transfer standards or standard reference materials. By performing this benchmarking process, the hot box operator is able to develop the additional equations that predict the magnitude of the corrections to the net heat flow through the specimen that account for any hot box wall loss and flanking loss. This benchmarking provides substantial confidence that any extraneous heat flows can be eliminated or quantified with sufficient accuracy to be a minor factor of the overall uncertainty. 1.4 In order to ensure an acceptable level of result uncertainty, persons applying this test method must possess a knowledge of the requirements of thermal measurements and testing practice and of the practical application of heat transfer theory relating to thermal insulation materials and systems. Detailed operating procedures, including design schematics and electrical drawings, shall be available for each apparatus to ensure that tests are in accordance with this test method. 1.5 This test method is intended for use at conditions typical of normal building applications. The naturally occurring outside conditions in temperate zones range from approximately −48 to 85°C and the normal inside residential temperatures is approximately 21°C. Building materials used to construct the test specimens shall be pre-conditioned, if necessary, based upon the material’s properties and their potential variability. The preconditioning parameters shall be chosen to accurately reflect the test samples intended use and shall be documented in the report. Practice C870 may be used as a guide for test specimen conditioning. The general principles of the hot box method can be used to construct an apparatus to measure the heat flow through industrial systems at elevated temperatures. Detailed design of that type of apparatus is beyond the scope of this method. 1.6 This test method permits operation under natural or forced convective conditions at the specimen surfaces. The direction of airflow motion under forced convective conditions shall be either perpendicular or parallel to the surface. 1.7 The hot box apparatus also is used for measurements of individual building assemblies that are smaller than the metering area. Special characterization procedures are required for these tests. The general testing procedures for these cases are described in Annex A11 . 1.8 Specific procedures for the thermal testing of fenestration systems (windows, doors, skylights, curtain walls, etc.) are described in Test Method C1199 and Practice E1423 . 1.9 The hot box has been used to investigate the thermal behavior of non-homogeneous building assemblies such as structural members, piping, electrical outlets, or construction defects such as insulation voids. 1.10 This test method sets forth the general design requirements necessary to construct and operate a satisfactory hot box apparatus, and covers a wide variety of apparatus constructions, test conditions, and operating conditions. Detailed designs conforming to this standard are not given but must be developed within the constraints of the general requirements. Examples of analysis tools, concepts and procedures used in the design, construction, characterization, and operation of a hot box apparatus is given in Refs ( 1- 34 ) . 3 1.11 The hot box apparatus, when constructed to measure heat transfer in the horizontal direction, is used for testing walls and other vertical structures. When constructed to measure heat transfer in the vertical direction, the hot box is used for testing roof, ceiling, floor, and other horizontal structures. Other orientations are also permitted. The same apparatus may be used in several orientations but may require special design capability to permit repositioning to each orientation. Whatever the test orientation, the apparatus performance shall first be verified at that orientation with a specimen of known thermal resistance in place. 1.12 This test method does not specify all details necessary for the operation of the apparatus. Decisions on material sampling, specimen selection, preconditioning, specimen mounting and positioning, the choice of test conditions, and the evaluation of test data shall follow applicable ASTM test methods, guides, practices or product specifications or governmental regulations. If no applicable standard exists, sound engineering judgment that reflects accepted heat transfer principles must be used and documented. 1.13 This test method applies to steady-state testing and does not establish procedures or criteria for conducting dynamic tests or for analysis of dynamic test data. However, several hot box apparatuses have been operated under dynamic (non-steady-state) conditions after additional characterization ( 1 ) . Additional characterization is required to insure that all aspects of the heat flow and storage are accounted for during the test. Dynamic control strategies have included both periodic or non-periodic temperature cycles, for example, to follow a diurnal cycle. 1.14 This test method does not permit intentional mass transfer of air or moisture through the specimen during measurements. Air infiltration or moisture migration can alter the net heat transfer. Complicated interactions and dependence upon many variables, coupled with only a limited experience in testing under such conditions, have made it inadvisable to include this type testing in this standard. Further considerations for such testing are given in Appendix X1 . 1.15 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.16 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee. ====== Significance And Use ====== 5.1 A need exists for accurate data on heat transfer through insulated structures at representative test conditions. The data are needed to judge compliance with specifications and regulations, for design guidance, for research evaluations of the effect of changes in materials or constructions, and for verification of, or use in, simulation models. Other ASTM standards such as Test Methods C177 and C518 provide data on homogeneous specimens bounded by temperature controlled flat impervious plates. The hot box test method is more suitable for providing such data for large building elements, usually of a built-up or composite nature, which are exposed to temperature-controlled air on both sides. 5.2 For the results to be representative of a building construction, only representative sections shall be tested. The test specimen shall duplicate the framing geometry, material composition and installation practice, and orientation of construction (see Section 7 ). 5.3 This test method does not establish test conditions, specimen configuration, or data acquisition details but leaves these choices to be made in a manner consistent with the specific application being considered. Data obtained by the use of this test method is representative of the specimen performance only for the conditions of the test. It is unlikely that the test conditions will exactly duplicate in-use conditions and the user of the test results must be cautioned of possible significant differences. For example, in some specimens, especially those containing empty cavities or cavities open to one surface, the overall resistance or transmittance will depend upon the temperature difference across the test specimen due to internal convection. 5.4 Detailed heat flow analysis shall precede the use of the hot box apparatus for large, complex structures. A structure that contains cavity spaces between adjacent surfaces, for example, an attic section including a ceiling with sloping roof, may be difficult to test properly. Consideration must be given to the effects of specimen size, natural air movement, ventilation effects, radiative effects, and baffles at the guard/meter interface when designing the test specimen. 5.5 For vertical specimens with air spaces that significantly affect thermal performance, the metering chamber dimension shall match the effective construction height. If this is not possible, horizontal convection barriers shall be installed inside the specimen air cavities at the metering chamber boundaries to prevent air exchange between the metering and guarding areas. The operator shall note in the report any use of convection barriers. The report shall contain a warning stating that the use of the barriers might modify the heat transfer through the system causing significant errors. For ceiling tests with low density insulations, the minimum lateral dimension of the specimen shall be at least several times the dimension of the expected convection cells. 5.6 Since this test method is used to determine the total heat flow through the test area demarcated by the metering box, it is possible to determine the heat flow through a building element smaller than the test area, such as a window or representative area of a panel unit, if the parallel heat flow through the remaining surrounding area is independently determined. See Annex A8 for the general method. 5.7 Discussion of all special conditions used during the test shall be included in the test report (see Section 12 ).