AIVC - Air Infiltration and Ventilation Centre

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Indoor air quality, ventilation and energy studies in hot and humid climates.

Considers how ventilation provision affects the indoor air quality in tropical climates, and the energy aspect. Describes a series of research projects aimed at obtaining a detailed database of IAQ, ventilation and energy measurements, carried out in Singapore in the mid to late nineties. Obtained the overall energy consumption of a dedicated air handling unit that served the zones in which the relevant IAQ and ventilation measurements were done. Presents the results for five air conditioned buildings in Singapore.

Soft air conditioning in storage rooms.

Investigates the possibility of limiting ventilation in archival storage areas when the outside conditions would have a detrimental effect on the humidity. Conducted measurement-based simulations on the Vaud state archives in Lausanne, Switzerland, with a continental mild climate. Recommends good insulation and high thermal mass.

A method of assessing the utilisation of outdoor air for summer cooling in warm/humid climate.

The study developed a method to assess the capability of outdoor air utilized for summer cooling in urban apartments in the hot, humid climate of Taiwan (average yearly temperature 23 Deg C, average humidity 85%). The assessment method is approached using three aspects of identifying the maximum comfort room temperature, estimating the cooling capacity of applied outdoor air volume, and calculating the required outdoor air and pre-cooled outdoor air volumes for cooling through cooling load calculations.

Mechanical ventilation protects one-storey single-dwelling houses against increased air humidity, domestic mite allergens and indoor pollutants in a cold climatic region.

States that poor ventilation is a factor in raising humidity levels in well insulation cold climate housing. Aimed to look at the ventilation rates in houses with varying ventilation systems, noting indoor air humidity, domestic mite allergen levels and VOCs. Enzyme-linked immunosorbent assay was used to measure levels in 59 similar one-storey single family houses. 22 houses had an added mechanical supply and exhaust ventilation system.

Effect of central air conditioning and meteorologic factors on indoor spore counts.

The effect of residential central air conditioning on indoor spore counts was investigated. Six pairs of residential buildings were monitored for three days. The homes were both air conditioned and non-air-conditioned. An Andersen sampler was used and outdoor measurements were also taken. Kitchens and bedrooms of air conditioned homes revealed significantly lower spore counts. The study used multiple regression analysis to show that the lower spore counts were associated with lower relative humidity.

The acute effects of humidifiers on asthma morbidity.

In order to examine the possible effects of humidifier use on asthma control, a randomised controlled study was performed. No significant differences were found when analyses were restricted to portable humidifiers, allergies to mites and/or moulds, and infrequently cleaned humidifiers.

Ventilation humidity control in residences in hot summer and cold winter region. Part 2: Ventilation humidity control strategies in residences.

On the bases of the definitions of air conditioning period, dehumidifying period and heating period, this paper puts forward to the exchanging conditions and psychometric process of ventilation system in residences. In order to improve on thermal environment quality and indoor air quality (IAQ), new strategies must be found to control both temperature and humidity of ventilation system.

Ventilation humidity control in residences in hot summer and cold winter region. Part 1: Standard summer meteorological parameters and ventilation cooling loads.

This paper founds the procedures of standard summer meteorological parameters in hot summer and cold winter region, determines the hourly meteorological model of dry and wet temperature change for sunny days, cloudy and rainy days, and builds up Chongqing's standard summer meteorological parameter database. Then based on hourly-degree method, this paper also analyses the ventilation cooling loads with new concepts such as ventilation cooling load index (VCLI), ventilation cooling temperature degree hour (CDH), cooling wetness hour (CWH0 and cooling enthalpy hour (CEH_.

Gray predicting control theory and corresponding control scheme for the indoor environment based on multi-strategies for controlling indoor humidity.

Indoor air humidity is an extremely important environmental parameter that can significantly affect the energy consumption of a building, its structure, the chemical emissions from building materials, as well as occupants' comfort and health. How to control indoor relative humidity has been the subject of much attention in the past decade. This paper expounds the passive and active control strategies, introduces a new control theory with a corresponding control scheme, and gives a simple simulation of a typical controlled room.

Moisture, building enclosures and mould.

Explores how water gets into a structure, why it doesn't leave, and how these architectural flaws become HVAC problems. States that mechanical engineers need to understand the roots of the problems in order to defend their work if IAQ becomes a problem once the building is occupied. The article reviews air control and pressurization, ventilation and humidity control and provides some resources to help expand the reader's knowledge of design and construction errors that lead to HVAC problems.