English

For many commercial and industrial plants, maintaining required ventilation rates can result in significant operating costs. Fortunately, passive (i.e. enthalpy exchangers) and active (dehumidifying) desiccant systems can be used to reduce the load on the HVAC equipment and reduce its operating costs.

Results from 100 apartment buildings built in 1990’s in Finland were compared. Apartment buildings were divided into three main groups; Mechanical exhaust only, mechanical supply and exhaust air systems with heat recovery centralized solutions and de-cent

With the analysis of the U.S. EPA BASE data from 100 U.S. office buildings, the authors made associations between moisture and ventilation system contamination with lower respiratory and mucous membrane symptoms . For that they used multivariate regression models .

Data centers need good air conditioning systems that maintain the temperature around the equipment. The use of VAV variable volume air conditioning in that data centers is The paper focuses on the saving of energy consumption with VAV systems installed in data centers.

The ozone (O3) has become an interesting atmospheric pollutant due to the complexity of thetransfer phenomenon to the indoor environment. The study of this phenomenon representedthe main objective of the French national research program PRIMEQUAL PREDIT. Theexperimental work, carried out in eight schools in La Rochelle France, proved that the O3 transfer could be predicted as a function of the outdoor concentration level and the airtightness of the building faade.

The protection of non-smokers against tobacco smoke is a very popular subject. In Japan,the health promotion law was passed in 2002. However, in restaurants and pubs, thepreventive actions against environmental tobacco smoke (ETS) are inadequate and ineffective. This paper presents ETS measurements taken in a restaurant and a computational fluid dynamics (CFD) simulation to reproduce the measurement condition.Several ventilation systems to improve the air quality in non-smoking zones are studied byCFD case studies.

The methods of tracer gas measurement are just well known in the fields of scientific and research. This study gives a summary of the basics and the application ranges of tracer gas measurement.A gas that is not component of the air, normally nitrous oxide (N2O) or sulphur hexafluoride (SF6), is released, distributed through the air flow and detected by an analyser. Tracer gas measurement can be used e.g.

In Finland eight office buildings were investigated as a part of European project HOPE..There were four office buildings with mechanical supply and exhaust air ventilation systemfrom 1970 and 80 without cooling system. The four other buildings had cooling systems;one with traditional central air conditioning system with cooled supply air system, the threeothers had chilled ceiling or beams in each office rooms. Altogether 800 office employeesfilled and returned the questionnaire.

A mathematical model was constructed to simulate time dependent particle concentration inindoor air and to evaluate the exposure of occupants. The model consists of three main parts:(1) a system model to describe the ventilation system and building envelope, (2) a multizone room model, and (3) a dose model. Models (1) and (2) are coded with Neutral Model Format and solved in the IDA simulation environment, and Model (3) in LUDEP (LUng Dose Evaluation Program). Particle deposition mechanisms were formulated with well-known equations.

This paper sums up the current results of the IAQ characteristics in 104 child care centers (CCC) , using 4 different ventilation strategies.The corresponding respiratory health symptoms of attending children with their frequency and prevalence rates are summarized too.Temperature, relative humidity and ventilation rates of naturally ventilated CCCs were consistently higher than that of air-conditioned CCCs.