The published REHVA guidebook provides comprehensive uptodateinformation aboutdesign features, criteria for cleanliness, inspection and cleaning instructions of ventilationsystems. The guidebook is aimed at practitioners, designers and those who are setting criteriafor cleanliness of ventilation systems. The design practice includes guides to construct a cleanventilation system and which cleanliness can be maintained during whole lifetime of thebuilding.

The objectives of this study are to reproduce in the laboratory different levels of cleanliness innon-porous ducts of HVAC systems, to compare a new method for sampling surface dust inducts with those methods cited in the literature, to compare the numerical evaluation methodto the visual method, and to propose objective cleaning initiation criteria.

The relationship between construction activities and an increased risk of microbial contamination and degradation of air quality in new building construction and renovation projects was studied. Poorly designed or installed ventilation systems and inferior workmanship during construction were determined to have an adverse impact on the performance of the building ventilation system. This presentation will provide guidelines to protect HVAC system components during building construction and renovation projects and for building commissioning procedures for building ventilation systems.

A research project has been carried out to develop new methods and technical solutions torefurbish ventilation and air-conditioning systems of office and commercial buildings builtduring 1970`and 1980`. More than twenty refurbishment concepts have been developed,which deal with all parts of ventilation and air-conditioning system (air-intake, filtering,cleaning, tightening and balancing of ductwork, noise control, air distribution, demand basedventilation, night cooling, adding mechanical cooling etc) and which can be carried out oneby one or all together depending of the actual needs.

The design of buildings for animal keeping and the dimensioning of ventilation equipment forsuch buildings require knowledge about heat, moisture and CO2 production of the animals. Inaddition to these parameters the emission streams of odour and gases are interesting on thepart of action on the environment. Therefore basic research was carried out in different cattlebarns, different designed buildings and different number of animals under one roof. Specialinvestigations were done in two naturally ventilated livestock buildings for 288 dairy cowsand for 251 beef cattle.

Cfd-calculations were performed to test whether it is possible to separate a non-smoking zone from a smoking zone using an air curtain. The cfd-calculations resulted in the following conclusions: 1. A larger exhaust flow is best. 2. An air curtain with a low air curtain velocity and an air intake from the smoke zone (as opposed to an air intake from the non-smoking zone) has the lowest smoke concentration in the non-smoking zone. 3.

The subject of this paper is the numerical simulation of the capture of contaminants with a local exhaust system. The objective is to evaluate the influence of multi-slotted hoods on the capture efficiency and its impact on indoor air quality. The ventilation in the proximity of slots and the contaminant dispersion throughout the room were predicted using the commercial tool Fluent. Characteristics of the polluted air were examined for different geometrical opening configurations for a two-dimensional model. Two parameters were examined: the number of slots and the slot width.

Three dimensional simulation of flow and material dispersion processes inside the enclosuresof machine tools opens up perspectives of assessment not by far achievable experimentally.Visualisations of these processes in terms of velocity and directions, temperature and pressureallow for an in-depth understanding of the processes and their consequences in view of a reductionof emitted metal-working fluid aerosols. This is demonstrated by one example fromthe machine tool laboratory (Werkzeugmaschinenlabor, WZL) at the University of Aachen(Rheinisch-Westflische Technische Hochschule, RWTH).

This paper presents design considerations of ventilation and indoor environmental quality(IEQ) for a control center. Raised access floors are extensively used to provide flexibilitiesfor control cables and wires required by a control center. Underfloor air distribution system(UFAD) is more practice and economical than an overhead mixing system. It improvesindoor ventilation effectiveness due to the air stratification of thermal plume, and it provides abetter indoor environment for the equipment and occupied people.

This text contains attainments from indoor climate and air conditioning equipment monitoringin clean rooms in the public health service. The editor is designer of HVAC systems inthe modern hospital near Brno in the Czech Republic. The text includes the experiences fromthe design phase as well as from the function the hospital. Monitoring of the HVAC systemsenables during 2 years operation efficiency evaluation of heat recovery system from waste air.We are able to evaluate its economy effect. And benefit of heat recovery system depends ofcourse of outdoor climatic conditions.