The paper presents a study on application of pressurisation tests of selected apartments as a base for analysis of natural ventilation in multi-family building. The analysis has been performed for 5-floor building constructed in late sixties. 10 apartments from a total number of 45 have been selected for pressurisation tests. The discussion presents estimations of windows' air tightness, the influence of additional air sealing on windows' infiltration coefficient and flow rates at reference conditions.
Indoor and outdoor particle concentrations and ventilation rates were measured versus time ina large office building without tobacco smoking. Periodically, high efficiency filters replacedthe normal filters in air handling systems. For all particle sizes, indoor concentrations variedconsiderably with time. Even with the normal air filters, which have a low efficiency forsubmicron particles, number concentrations of submicron particles were a factor of three tosix smaller indoors compared to outdoors.
This paper presents ozone removal efficiencies, measured over an extended period of time, inthree different settings: a test plenum, an air handler providing outdoor air to a Class 100cleanroom, and a plenum downstream of an air handler providing outside air to a second, smallerClass 100 cleanroom. In each of these settings, the initial ozone-removal efficiencies werecomparable. After 8 years of service, the charcoal filters servicing the first cleanroom wereremoving about 60% of the ozone in the airstream.
The design of natural ventilation systems - the configuration and sizing of system components - assumes one of two generic forms: the nasty form based on thermal comfort criteria or the nice form based on specified airflow rates. The nasty form demands consideration of the complex coupled interaction of a building's airflow and thermal systems - a difficult and often intractable challenge. The nice form, on the other hand, is quite tractable, yet it is commonly approached using interactive and approximate techniques.
In residential buildings, air-conditioners are usually operated in intermittent mode. Thisintermittent mode may complicate many aspects of indoor environments. Indoor humidityexcess is a major problem, since humidity excess is associated with biological pollution andformaldehyde emission. This paper reports our monitoring of indoor air temperature andrelative humidity in a real life building in the hot humid Hong Kong climate. These monitoredresults indicate that, in residential buildings, occupants habits in using windows for naturalventilation exacerbate indoor relative humidity excess.
Many HVAC systems built in the time between 1960 and 1980 have now reached the end oftheir lifetime and require retrofitting. When HVAC retrofits are performed in connection withbuilding renovation, there is often a potential for reduction of thermal loads. The questionwhether a renovated building should have an airconditioning plant or free ventilation oftenrevolves around arguments of energy consumption and investment. However it is not takeninto account that there can be no thermal comfort in many cases of cooling loads and outdoortemperatures.
In recent years, increasing importance has been placed on energy efficiency in residentialbuildings. This has resulted in tighter buildings, which raises concerns about the amount ofventilation required to provide acceptable indoor air quality. Relatively few studies have beenconducted on multifamily buildings, where the multiple zone interaction makes testing andanalysis difficult. In order to address this problem, detailed testing of air flows, pressures, andtemperatures was done at three electrically-heated multifamily buildings in the U.S.
This presentation deals with the problem of achieving stable microclimate in old buildings ofSt Petersburg - such as churches, museums and palaces. Characteristic traits of such buildingsare rather thick envelops which as a rule accumulate large quantities of heat or cold. Themajority of these buildings are equipped only with central water heating and are naturallyventilated.Experimental study of microclimate in buildings of this kind proves that during cold season(with average temperature -10C) the relative humidity there will be about 30-35% and less.
A general trend in intelligent buildings is the decentralization of environmental controlsystems. Decentralized environmental control systems have many advantages over centralizedsystems. In order to filly utilize a decentralized control system, the control zone should becompletely individualized so that one occupant can feel free to adjust the air volume andtemperature without being concerned about affecting the comfort of other occupants. Afurniture integrated air distribution control system can provide highly individualizedenvironmental control.
Classrooms in New Zealand schools are mostly low rise buildings with natural ventilationdesigns, sized for summer cooling. This study has investigated winter ventilationperformance in twenty-four classrooms in twelve primary schools in the Wellington region.Its purpose has been to provide baseline data on the effectiveness of existing naturalventilation, along with approximate pollutant profiles on which to base new mixed modeventilation designs.
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