English

The Finnish Society of Indoor Air Quality and Climate has prepared a proposal for the classification of the cleanliness of new ventilation systems and components. The document supplements the classifications of indoor climate, construction cleanliness and material emissions published in 1995. The classification of the cleanliness of the ventilation systems consists of two parts: a classification of the cleanliness of ventilation components and a guideline for the design and construction of clean ventilation systems. The proposal will undergo an open review during next winter.

The Swedish Parliament decided 1991 that ventilation systems in all non-industrial buildingsshould be regularly inspected in intervals from 2 to 9 years, shortest for schools, hospitals etcand longest for natural ventilated flats. The systems are checked to fulfil the requirementsgiven when installed.The goals of the evaluation were to give estimated rates for how many systems that wereapproved at the end of 1997 and the cause of the faults that made the system either not to beapproved or to be remedied before next inspection.The evaluation was made in three steps:1.

Ventilation systems with heat recovery offer several advantages such as, of course, energy savings but also the possibility to add acoustic and filtration treatment. This study was to evaluate the thermal performances of such systems for residential ventilation in France. These units usually combine exhaust and supply fans, filters and a heat recovery exchanger. To test them, a special draft is being written by the CEN experts of TC 156/WG/AH7.

Based on the fundamental flow equations, a set of formulas is derived for air velocities, temperature differences and ventilation rates in relation to number of openings, opening areas, net heat input, building geometry, and temperature stratification. The use of the formulas is illustrated on a three-storeyed office building.

Analytical solutions are derived for calculating natural ventilation flow rates in a single-zone building with two openings when no thermal mass is present. In these solutions, the independent variables are the heat source strength and wind speed, rather than given indoor air temperatures. Three air change rate parameters a, B and y are introduced to characterise respectively the thermal buoyancy force, the conduction heat loss effect, and the wind force. The wind can either assist the buoyancy force or oppose it.

In this paper ventilation strategies are examined in order to improve the thermal performanceof an attached sunspace of a two-storey semi-detached house in the area of Athens Greece.The ventilation strategies examined are cross and single-sided ventilation through the verticalwindows of the sunspace. Simulations were conducted implementing multizone ventilationmodel COMIS coupled with the thermal simulation model Suncode.

A systematic analysis of recently constructed dwellings in the Flemish Region has beenundertaken within the SENVIVV-project (1 995- 1998) [I]. In total 200 dwellings have beenexamined in detail. The study involved various aspects: energy related building data (thermalinsulation level, net heating demand, installed heating power, etc.), indoor climate(temperature levels in winter and summer), building airtightness, ventilation, appreciation ofthe occupants, etc. This paper focuses on the results of the airtightness measurements thatwere undertaken in 51 of the 200 investigated dwellings.

We examine natural ventilation in buildings with multiple storeys, each storey linked to acommon chimney or atrium, and ventilated using 'top-down chimneys' to draw in relativelyunpolluted air from openings located high above street level. Two significant issues relatingto ventilation design and management are addressed. First, the common stack providesconnections between every storey and, consequently, the ventilation of each storey cannot becalculated in isolation, but must be calculated simultaneously for all storeys.

The paper describes the results of a Pan-European survey carried out on identifying thebarriers that restrict the implementation of natural or simple fan-assisted ventilation systems inthe design of new office-type buildings and in the refurbishment of existing such buildings.

The Ventilation Standard HASS-102 of The Society of Heating, Air-conditioning andSanitary Engineere of Japan (SHASE Japan) was revised in November, 1997. The title of therevised standard is Ventilation Standard for Acceptable Indoor Air Quality. So far, the oldVentilation Standard, which was issued in 1939, had been used for a long time. The task forrevision was undertaken by the Sub-committee on Ventilation Effectiveness and Standard(chaired by Murakami) of SHASE Japan.