heat recovery

Natural ventilation based on Passive-stacks are currently designed without incorporating heat recovery leading to wasteful heat loss. Heat recovery is not used because the pressure loss caused by conventional heat exchangers is large and could cause the ventilation system to fail. This paper presents laboratory investigation and computer simulation of a low pressure-loss heat recovery device for passive stack systems. It was found that the heat recovery effectiveness decreases with increasing stack velocity and heat recovery effectiveness of over 50% has been obtained in the experiments.

This study examines the use of energy recovery ventilators (ERV) in two schools located in a Southwestern arid climate as an energy-efficient means of providing acceptable ventilation to the classrooms and the corresponding effect on indoor air quality (IAQ) contaminant indicators. The effect of cleaning the existing systems· on thermal comfort conditions were also examined. IAQ measurements were made in selected classrooms with respect to carbon dioxide, viable and non-viable bioaerosols, volatile organic compounds, and respirable particles.

In some ventilation and dust removing system of workshop, a great deal of energy is wasted due to heated and cooled indoor air being exhausted directly. So if the dust in the indoor air is removed and then recirculate, the objective of energy saving can be reached. In this paper, the calculation equation of dust concentration, relative humidity in indoor and recirculate air and heater capacity are given along with the control measures to them.

In a way most heat pumps recover or reclaim heat energy for space heating and cooling, water heating or process heating. In the building sector, the natural heat sources which heat pumps transfer to useful heat, such as outside air, the ground, ground water and sea/lake/river water are in fact all heat sources that consist of solar heat and cannot be directly used for heating due to their temperature. Hence, one can argue that heat pumps which use these sources are (solar) heat-recovery devices.

In Amstelveen, The Netherlands, an apartment complex of forty two units has been build. Sixteen units are extreme low energy apartments. These apartments are very well isolated and have air tight facades.