This paper reports a comparison of models for estimating the return time from a night setback condition. Fifty-seven models are compared using simulation data that include the influence of climate, building mass, controller tuning, room orientation, and the unoccupied control strategy on return time. Two-parameter models are recommended for estimating the return time for both heating and coolin...

Design of a thermally comfortable indoor environment requires detailed information about distribution of air velocity, air temperature, relative humidity, and mean radiant temperature and about heating/cooling load in a space. This research has developed a coupled airflow-and-energy simulation program to calculate simultaneously the distributions of indoor airflow and thermal comfort and heatin...

Having a continuous growth in the energy demand for heating, together with decreasing the availability of fossil fuels, renewable energy sources have become an important point of departure and specially air to water heat pumps have been suggested for domestic heating. Using them the main challenge is to be sensitive to the both outdoor air temperature and the indoor energy demands to minimize t...

Preform heating is one of the most important steps in the polymer fibre fabrication process due to the potential distortion that can be introduced when exposing the structure to high temperatures. Such heating is further complicated when internal air-structures are introduced into the preform such as in Microstructured Polymer Optical Fibre (MPOF) preforms. The aim of this study was thus to inv...

Depending upon one's perspective, distributed control has had an either extremely long, or extremely short history in the application of heating, ventilation, and air-conditioning (HVAC) control. HVAC systems have been in existence for the entire duration of human architecture, at least in terms of heating, with air-conditioning arriving in the 1800's with the industrial revolution, as a means ...

A wide range of existing power technologies can make use of the solar energy reaching Earth. Basically, all those ways can be divided into two basic categories: transformed for use elsewhere or utilized directly – direct – and involving more than one transformation to reach a usable form – indirect. The Solar Chimney Power Plant (SCPP) is part of the solar thermal group of indirect solar conver...

Although individuals spend the majority of their time indoors, most epidemiological studies estimate personal air pollution exposures based on outdoor levels. This almost certainly results in exposure misclassification as pollutant infiltration varies between homes. However, it is often not possible to collect detailed measures of infiltration for individual homes in large-scale epidemiological...

Recently builders have shown considerable interest in combining the features of active and passive solar space heating systems into a hybrid system employing active collection and some form of passive discharge/storage device. Ye examined the performance and economics of a hybrid2 air-based, residential system using 18.5 m of roof-mounted air collectors and a hollow-core slab that discharges di...

The surface heat transfer efficiency of three heating media (water, and forced air with and without a water vapor-pressure deficit) was compared using four commodities: mango, papaya, grapefruit, and orange. Forced vapor-saturated-air (VFA), and water (HW) transferred heat most efficiently to the fruit surface. Thermal stress to the fruit was greatest during heating in VFA. Thermal diffusivity ...