AIVC - Air Infiltration and Ventilation Centre

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Predicting indoor temperature and humidity conditions including hygrothermal interactions with the building envelope

The hygrothermal behavior of the building envelope affects the overall performance of a building. There are numerous tools for the simulation of the heat and moisture transfer in the building envelope and also whole building simulation tools for energy calculations.

Moderating indoor conditions with hygroscopic building materials and outdoor ventilation

This paper contains a numerical study of the indoor temperature, humidity, and comfort and indoor air quality conditions in a bedroom located in Saint Hubert, Belgium. The performance of the bedroom is presented for a range of constant outdoor ventilation rates (0.1 ach to 1 ach) with and

Evaluation of moisture buffer effects by performing whole-building simulations

The humidity of rooms and the moisture conditions of materials in the enclosure of buildings depend much on each other because of the moisture exchange that takes place over the interior surfaces. These moisture influences also depend strongly on the thermal conditions of indoor spaces and enclosure elements of buildings. In turn, the moisture and humidity conditions have significant impact on how buildings are operated.

Indoor humidity modeling and evaluation of condensation on interior surfaces

In tropical humid climates, moisture and condensation on walls lead to significant damage of buildings. The purpose of this article is to present a numerical model to improve the prediction of internal humidity in buildings. Thermal simulation codes usually evaluate moisture due only to airflow transfers. The model presented takes into account the moisture transfers between walls and air inside a zone. It allows a forecast of the quantities of liquid condensed on a surface. An experimental comparison is presented to appreciate the improvement of the model.

Dampness in buildings as a risk factor for health effects, EUROEXPO : a multidisciplinary review of the literature (1998 - 2000) on dampness and mite exposure in buildings and health effects

Both in domestic and public environments, dampness in buildings is a risk factor for health effects. A European group of scientists has reviewed the literature on that subject including mite exposure over the period 1998-2000. That review has shown that there is a huge need for multidisciplinary reviews in scientific papers including associations between indoor environmental factors and health effects.

AIVC/BETEC conference Washington - October 2003 -

This paper is the summary of the 2003 AIVC/BETEC conference with its different parts: Health and Building Science, Building evaluation, Single-building studies, Experimentation, Building science, Strategies and New directions.

Indoor air quality in two different commercial buildings: Part 1: ventilation, temperature, humidity of air and gas concentrations

The main objective of this study was to investigate the Indoor Air Quality (IAQ) in officebuildings and to understand better how HVAC (Heating, Ventilation and Air-conditioning)systems work and what their effects are on IAQ over a sustained period. Two Frenchcommercial buildings were chosen, located in urban areas of Lyon and Paris, and for one daya month, over the course of 1 year, a number of IAQ related variables were recorded bothinside, including the HVAC system, and outside the buildings.

Subjective experiments on the effects of relative humidity and humidity ratio during summer season

In order to clarify the effects on comfort and health of relative humidity and humidity ratio,subjective experiments were conducted in a climate chamber in Japan during the summer of2002. Fifteen subjects were exposed for 180 min, while being engaged in simulated officeworks and questionnaires. The experiments were conducted at a constant SET* (StandardNew Effective Temperature) with six different humidity conditions, namely [30%RH/6.13 g/kg],[37%RH/6.13 g/kg], [37%RH/7.45 g/kg], [45%RH/7.45 g/kg], [45%RH/8.97 g/kg],[55%RH/8.97 g/kg].

Effects of humidity and indoor air chemical pollutants on human comfort and productivity

Subjective experiments were conducted in summer and winter in order to clarify the effects ofhumidity and indoor chemical pollutants on subjective comfort and productivity, and evaluatethe seasonal differences in their reactions. Subjects were exposed to three levels of humidityconditions and 2 indoor air quality levels in a climate chamber performing the simulatedoffice works. For all conditions, SET* was constant. Subjects adapted to the indoor air qualityduring the 180-min exposures under the polluted conditions.

Objective and subjective responses to low relative humidity in an office intervention study

The impact of dry indoor air on comfort and health in winter was investigated in a crossoverintervention study in two floors of an office building in northern Sweden. The indoor airhumidity (normally 10-20% RH) was raised to 23-24% RH, one floor at a time, using steamhumidifiers. Questionnaires and objective (clinical) measurements were applied.