This contribution reports on investigations about the performance of decentralised ventilation units with heat recovery. Such units can be easily installed in individual rooms and therefore offer an interesting alternative to central ventilation units. Nevertheless these units exhibit some problems. Experimental examinations of two commercial decentralised units showed that the real effectiveness of heat recovery was always below 50 % and that considerable leakage between the air ducts can result in poor indoor air quality.
This paper proposes a new personal air-conditioning system, which modifies a common partition used in offices to a partition-type fan-coil unit (PFCU) with inlets and outlets on its surfaces. Chilled water is supplied as the cooling energy, and is delivered to the partitions by pipelines incorporated into the structure. Hence, conventional air conditioning systems using ceiling-based air diffusers for open-plan offices may be dispatched into several small individual systems controlled by the occupants.
Thermal comfort (PMV and PPD indices) of a floor return underfloor ventilation system was evaluated through experiments with different supply air temperatures and internal heat loads. Results are shown and analysed.
CSTB has built an experimental house MARIA: Mechanised house for Advanced Research on Indoor Air. The house is dedicated to study pollutants transfers, test ventilation systems, settle field investigation methods, and validate computational models. MARIA will be instrumented and automated according to pre-established scenario of operation reproducing parameters related to human presence and behaviour. The human presence is simulated with heat load and water vapour and pollutants emission. The operation of equipments such as doors and windows, domestic devices, will be automated.
In addressing the goals of energy-efficiency and indoor air quality (IAQ) in homes, industry teams in the U.S. Department of Energy's Building America program are installing mechanical ventilation systems in tight homes. A variety of designs - some simple and inexpensive, some more sophisticated - have been demonstrated. The advanced designs provide more consistent ventilation over time, more uniform ventilation among rooms, and source control measures that reduce the air-change requirement.
Although most of the apartments adopt state-of-the-art convenience facilities, since they have become the most popular housing type in Korea, they depend on natural ventilation for HVAC systems, as traditional floor heating systems (Ondol) are used. On the other hand, the indoor environments of the apartments have become more important, because people stay longer in a room and the room environment is polluted, because of various kinds of interior materials. Accordingly, some apartments apply air conditioning systems using AHU and ventilation systems using heat exchangers.
This paper presents an analysis of air-to-air total heat exchangers (heat and mass transfer) built up using moisture permeable paper (but impermeable to air molecules). Performance of 6 such total heat exchangers made of different types of paper were tested, in order to know their air leakage ratio and their energy saving ratio. An analysis is presented about the effect of leakage on energy recovery efficiency.
A design procedure of material and hybrid ventilation systems is described. It includes a climate suitability analysis, a loop equation design method and a detailed multizone coupled thermal-airflow analysis using CONTAM97R software.
A Norwegian research project in under progress to develop a new concept for control of air movements in protection isolates, operating theatres and other risk areas in hospitals. The aim is to reduce airborne hospital infections through appropriate design of building, HVAC installation and control of air movements. A container solution was developped for isolates. Its HVAC system, and especially the ventilation system are described in details. The first container has been finished in June 2002 to be tested.
To minimise emissions from ducts, it is necessary to manufacture with low emission lubricants or with lubricants that leave only minor amount of residues on the surface. In this study the lubrication, evaporation and odour emission properties of fourteen lubricants were studied and differences are high ligthted showing the importance to select them properly.
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