PR1999

In order to evaluate the impact on indoor air quality of different installation and ventilation strategies, the modelling of indoor air pollutant transfer has been developed in the CLIM2000 software (thermal and airflow code). Then, these models have been used to simulate the evolution of indoor air pollution in an office building floor for a week in winter under different ventilation strategies. The selected pollutants are CO2, CO, NO2 and HCHO and the sources are outdoor pollution for all pollutants and occupancy for CO2. So far, humidity has not been taken into account.

Based on concerns about indoor air quality and trends towards tighter envelope construction,there has been increasing interest in mechanical ventilation of residential buildings in the UnitedStates. This paper reports on a situation study of indoor air quality, ventilation and energyimpacts of several mechanical ventilation approaches in a single-family residential building Thestudy focuses on a two-story house in the northwestern United States and employs themultizone airflow and contaminant dispersal model CONTAM96.

In laboratory experiments, we investigated the ability of two task/ambient conditioningsystems with air supplied from desk-mounted air outlets to efficiently ventilate the breathingzone of heated manikins seated at desks. In most experiments, the task conditioning systemsprovided 100% outside air while a conventional ventilation system provided additional spacecooling but no outside air. Air change effectiveness (i.e., exhaust air age divided by age of airat the manikins face) was measured.

The air quality in a subway-train was studied to suggest optimal design criteria and operationconditions based on the ventilation demand by passengers. The C02 emitted from thepassengers was the tracer for this study. The C02 bioeffluent from a human body was firstlyquantified and used for the data analysis. Then the C02 concentration was monitored in asubway-train being operated.

Within an International Energy Agency (IEA) project (Annex 27) experts from 8 countries(Canada, France, Italy, Japan, The Netherlands, Sweden, UK, and USA) have developed toolsfor evaluating domestic ventilation systems during the heating season. Building and useraspects, thermal comfort, noise, energy, life cycle cost, reliability, and indoor air quality(IAQ) tools were developed.

It is the objective of the present paper to investigate indoor environmental characteristics ofan office building with an underfloor air conditioning system. Thermal conditions in the roomwere monitored including horizontal and vertical temperature distributions, supply andexhaust air temperatures, and globe temperature. Indoor air quality was investigated bymeasuring carbon monoxide, carbon dioxide and airborne particulate. Velocity distributionsaround a floor air terminal, and thermal comfort around a supply air terminal were alsoinvestigated.

An efficient ventilation system is characterised by a well-organised and turbulence-controlled airstream that rapidly corrects disturbances in air quality and thermal comfort in the ventilated space.Air supply and exhaust conditions are investigated here in order to find stable flow conditions andan efficient elimination of both gas and solid phase contaminants. Heat and thermal comfortrequirements are also included.

The study was to test five units used in single house mechanical ventilation systems with heat recovery. Tests were made according to CEN project prepared by CEN TC 156/WG2/AH7 including air tightness, pressure-airflow's curves and temperature ratios. A full test on frost and condensation was also realised on one unit to determine the influence of these parameters on performances. Test results, influence of wet or dry conditions and main conclusions for using these results in dimensioning, will be given.

Surveys on repressurization-induced backdrafting and spillage were conducted in threedifferent areas of the United States using a common protocol, primarily to assess thecorrespondence between short-term tests and one week of continuous monitoring per house.The short-term tests, under induced conditions, can only indicate whether there is a possibilitythat backdrafting or spillage might occur, whereas real-time monitoring under naturalconditions can give a true indication of backdrafting and spillage events.

The main objective of this study was to determine the ventilation demand for a gymnasium inthe primary school based on verified metabolic rate.Norwegian guidelines recommend 6.0met as the activity level to be used when calculating the outdoor air flow rate in a gymnasium.Younger pupils have a lower body mass and metabolic capacity than adults, and their demandfor ventilation is therefore lower. The metabolic rate has been assessed by measuring thepupils emission of the dominating bioeffluent CO2 during intensive gymnastic activity.