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The thermal response of flat slab specimens subjected to four sets of thermal boundary conditions is examined. The conditions are typical of thermophysical test apparatus, and the four sets of conditions are similar. Initial temperatures are uniform and the cold face temperature is stepped to the required value. There are four different hot face conditions: (1) constant temperature, (2) constant heat flow, (3) zero heat flow followed by constant temperature, and (4) zero heat flow followed by constant heat flow. Solutions are given for the heat transfer problems, and the equations are truncated, then inverted, to yield simple, approximate expressions for response time. The precision of the approximate equations is shown to be adequate for prediction purposes; the four sets of conditions are ranked in order of increasing response time; and the occurrence of optimum situations is noted.

The constants in an idealized heat flow simulation are adjusted by non-linear regression to match the experimental results of 107 fire endurance tests performed at the Portland Cement Association's laboratories. They are then used to predict fire endurances. Confidence limits are assigned.

The author uses the response factor determination method in calculating transient heat flow through walls and roofs, where surface heat transfer coefficients are not constant. This method is valid for periodic and non-periodic ambient conditions, and is suitable for calculations of surface heat transfer due mainly to radiation and evaporation.

This paper describes the results of an analytical study to determine the errors involved in using a linear methematical model to calculate with sufficient accuracy the elements of an air-conditioning installation; the purpose of the study is also to evaluate the effect of the architectural characteristics of a building on its cooling load. It is felt that a linear mathematical model, with the help of a digital computer, would predict cooling loads for air conditioning at reasonable cost. The linear mathematical model is based primarily on the assumption that convection and radiation heat transfer is directly proportional to the respective temperature differences. The calculations reveal that the cooling load is not closely related to the heat transfer coefficients of the surfaces. The results indicate that the mathematical model using a combined heat transfer coefficient for inside surfaces does not accurately represent the room thermal balance; in calculating the cooling load, similar elements in the room can be considered as a unit forming part of its envelope; in addition, lightweight room elements must be accounted for.

In this study air and ground temperature measurements taken over a 3-year period in a virgin peat bog are compared with similar measurements taken at nearby mineral soil sites. The purpose of the study was to access the significance of temperature differences that can be expected due to terrain and soil thermal properties. The drainage of cold air into the peat bog was found to be the major factor causing minimum air temperatures to be lower over the bog than at nearby weather stations. The condition of the bog, i.e. whether it was wet or dry, thawing or snow-covered, appeared to have some effect on minimum air temperatures but was not as important a factor as air drainage. Monthly and annual average peat soil temperatures were several degrees colder than corresponding mineral soil temperatures. The peat soil temperatures were colder because heat available from radiation and convection was used for evaporation rather than for warming the soil.

The thermal performance of walls, windows, doors and roofs is described by a number of characteristics. Both opaque and transparent elements are described by the over-all resistance to heat transmission, the inside surface temperature characteristic and the differential thermal movement behavior of the elements. In addition, transparent elements such as windows and glazed doors are described by the solar transmission characteristic and the thermal breakage resistance of the glazing. The factors affecting the foregoing characteristics and the methods available for their evaluation are herein reviewed.