How unbalanced return air encourages mold growth

There are two ways for unbalanced return air to produce moisture and mold problems during hot and humid weather : - the increased entry of outdoor air that substantially increases indoor relative humidity. - a negative pressure can draw moist air into wall cavities causing a moist interstitial microclimate, if indoor humidity is relatively low in the conditioned space.To prevent the creation of moisture and mold problems, properly sized return ducts should be provided.

Estimating effects of moisture damage repairs on students' health - long-term intervention study

After the moisture damage repairs, a health symptom questionnaire study was repeated 1 year, 3 years and 5 years on 245 upper secondary and high school students. The data were analyzed. The results indicate that no new cases of symptomatic students occured : in that sense the repairs succeeded.

Setting up a database of indoor climate measurements in recently built Belgian dwellings

One of the major sources of problems in dwellings -if not the main source- is moisture, especially due to surface and interstitial condensation on walls and roofs. For this reason, it seems important to evaluate the current standardisation and reference documents dealing with moisture and eventually to develop new assessment methods. This is the goal of the Belgian project "Moisture problems in roofs", carried out by BBRI, KUL, RUG and W&K. The first step is to collect a large number of indoor climate measurements in recently built dwellings built.

Dampness in buildings and health (DBH) : report from an ongoing epidemiological investigation on the association between indoor environmental factors and health effects among children in Sweden

The aim of this paper is to identify the link between indoor environmental factors and asthma or allergic symptoms among small children and their parents. That four-phases Swedish study will be lasting from 2000 until 2008 : First step : an epidemiological cross-sectional questionnaire on housing and health involving 14,077 preschool children (2000).Second step : a nested case-control study including 198 children with symptoms and 202 healthy controls.

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.

A preliminary investigation on the use of ultra-wideband radar for moisture detection in building envelopes

A preliminary investigation has been carried out to determine the potential for using ultra-wideband (UWB) radar to determine the moisture level within building envelopes. Radio waves are affected by moisture content because their reflection from the surface of a material depends upon the dielectric

Estimating effects of moisture damage repairs on students' health - a long-term intervention study

The aim of that study that lasted 5 years was to assess the effect of repairs made to moisture-damaged school buildings on the students' health. With repeated questionnaires it was possible to compare the occurrences of symptoms before and after the repairs in school.

Magnitude of the mould and moisture problem in Danish homes

The purpose of this study was to quantify the extent of moisture problems in Danish homes. Aquestionnaire-based survey was made and a representative sample of 3800 Danes older than15 years responded. Main results are that 17.6% of the people have had moisture damages intheir dwelling during the last 5 years and among those as much as 36.4% have not yetremedied the damages. A total of 17.7% have moisture or mould spots on their walls, ceilingsor floors.

Moisture conditions and energy consumption in heated crawl spaces in cold climates

The aim of that study was to find out if heating is the alternative for crawl space moisture control with a reasonable low energy consumption. Using a ground cover without thermal insulation and heating of the crawl space proved to be a good alternative method to control mold growth.

Moisture conditions in highly insulated outdoor ventilated crawl spaces in cold climates

The aims of that study were to find out how the thermal capacity, resistance, and the placement of insulation layers affect relative humidity in crawl spaces. The results show that there are two alternative ways to use ground covers in combination with air change to achieve acceptable conditions in crawl spaces.

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