A study of thermal comfort in an office environment with floor return type underfloor ventilation system

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.

MARIA: an experimental tool at the service of indoor air quality in housing sector

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.

Barriers to improved ventilation in production housing

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.

The evaluation of HVAC systems and indoor air quality of high-rise appartments

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.

A heat and mass transfer analysis of cross-flow air-to-air total heat exchangers made of moisture-permeable paper

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.

An approach to the design of natural and hybrid ventilation systems for cooling buildings

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.

Hospital airborne infection prevention

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.

Selection of lubricant for manufacture of HVAC components

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.

Oil residues on HVAC components

This study presents a literature review on oil residues on HVAC components. A sampling of oil residues by filter contact method and analysis by infrared spectroscopy method have been developped. Amounts of oil residues on surfaces of components varied a lot (<10 mg/m to 700 mg/m) but were significantly correlated to odour intensity. Cleaning of oil residues from the duct surfaces with typical cleaning methods is very difficult and it is better to deliver from the manufacturer components free of oil residues.

The exploitation of solar energy for energy-saving ventilation

Performance of solar systems used to preheat ventilation air was investigated through long-term (several years) measurements on three buildings in Czech Republic. Buildings and results are described.

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