English

Forced air furnaces are a common Canadian heating system. Traditionally, filters placed in thecirculating air ductwork were designed to protect the furnace and fans. Over the last severalyears, there has been increased emphasis on improving the filtration efficiency with the goal ofreducing occupant exposure to respirable particulate. The current research project rotatedseveral filters through six houses in southern Ontario during the heating season.

This paper deals with the internal environment of traditional excavated dwellings in Santoriniand the effect the conditions of the surrounding volcanic rock have on it. Three buildings weremonitored in the summer and winter and the results of the monitoring were used to simulatethe natural ventilation of the dwellings and calculate the amount of moisture which is releasedfrom the porous material of the walls. The study shows that the internal high relative humidityvalues are mainly due to this moisture release.

Ventilation filters composed of electrostatically-charged fibers, also referred to as electret filters,are know to have the potential to decrease in filtration efficiency with use. However, little datahave been available on whether such decreases are seen in actual applications.

It is recommended to keep the ventilation filters dry. However there are manyventilating systems that cannot fulfil this requirement all the time. It is then interestingto know the state of filters in use, and how they perform during extreme wetconditions, especially at the end of their lifetime.This investigation includes used filters collected at the time of normal change offilters.The used filters absorbed a different amount of humidity. The particle filtrationefficiency was nearly the same as for unused filters (comparing only filter classF7/EU7).

This study is part of an investigation of the decontamination capabilities of indoor plants.Three internationally used species, Howea forsteriana Becc. (Kentia Palm), Dracaenaderemensis Eng. Janet Craig, and Spathiphyllum Petite (Peace Lily), were evaluated for theability to reduce or remove benzene and n-hexane from indoor air. Plants tested in bothpotting media and hydroponic conditions removed the individual VOCs at concentrationsequal to 2 and 5 times the maximum occupational exposure levels recommended by theWorksafe Australia Time-weighted average exposure standard (TWA), [1].

With a diameter of 320m, and a height of 50m the Millennium Dome is one of the World's largest enclosed spaces, probably the largest among those intended for public use. This paper briefly discusses some of the Building Services issues involved in the design and construction of the Dome, concentrating on the ventilation, and heating/cooling of the building. Buro Happold are the engineers for the Dome responsible for Structural, Building Services, Fire and Access Engineering of the main structure and many of the exhibitions within it.

k order to determine the amount of micro-organism present before and after the filters ofHVAC systems, 6 systems in 5 buildings were monitored every 2 weeks for one year. Measurementswere taken in triplicate and simultaneously before and after the filters using a sixstage Andersen sampler.

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.