English

In Finland 12 apartment buildings were investigated as a part of European project HOPE. There were one building with passive stack ventilation with fan assisted exhaust air ventilation, four buildings with mechanical exhaust ventilation only and seven buildings with mechanical supply and exhaust air ventilation system. Altogether 600 questionnaires were returned. Modern passive stack ventilation system with separate exhaust fans in kitchen and bathroom did not assure sufficient ventilation even in March when ventilation rates and CO2-levels were measured.

In this paper we give an overview of the ways occupants use ventilation systems and describe the results of interviews conducted in households equipped with balanced ventilation. An attempt is made to quantify the effects of occupant behaviour on the final energy use of the household for heating. This energy use is studied for several behaviour scenarios, leading to the conclusion that occupant behaviour may easily reduce the predicted savings to zero, or even may increase the energy use when compared to natural ventilation.

This study focuses on the correlation between the airtightness of a building envelope and the average infiltration and energy consumption of a typical modern Finnish detached house. The correlation between tightness and infiltration was determined using an empirically validated dynamic IDA-ICE simulation model of a two-storey detached house. The effect of wind conditions, Finnish climate conditions, balance of ventilation system and leakage distribution on infiltration were studied with the simulation model.

The study aims at quantifying the impact of the retrofit of ventilation systems from the energy, IAQ (Indoor Air Quality) and health perspective. In a first part, the French market has been defined (number of each ventilation system installed in existing building). Both qualitative and quantitative studies of malfunctions noticed on ventilation systems have been made.
In a second hand, the influence of ventilation retrofitting on the building energy performance
has been evaluated. The impact of implementing innovative techniques (i.e. decreasing the fan

Airflow rates were measured in one hundred and two newly built single-family houses during 2002-2004. Of the measured houses, 10 % used natural ventilation, 28 % used mechanical exhaust and 61 % used mechanical supply and exhaust. Exhaust airflow rates were measured during the summer period from terminals. Supply airflow rates and sound pressure levels were measured in master bedrooms. During a 2-3 week period in winter, air change rates were measured with a passive tracer gas technique to determine the overall air change rate.

The first and only national norm for residential ventilation in the United States is Standard 62.2-2004 published by the American Society of Heating, Refrigerating and Air-conditioning Engineers (ASHRAE). This standard does not by itself have the force of regulation, but is being considered for adoption by various jurisdictions within the U.S. as well as by various voluntary programs. The adoption of 62.2 would require mechanical ventilation systems to be installed in virtually all new homes, but allows for a wide variety of design solutions.

Personal control over moving air will eliminate the number one complaint in the office environment - thermal discomfort. The use of moving air to cool provides the ability to accommodate different needs among people for comfort due to varying metabolism, efficiency of heat rejection, and clothing. Cooling with moving air saves substantial energy through increased ventilation effectiveness and higher operating temperatures. Increased comfort means increased productivity.

Control-on-demand operation of HVAC-systems can reduce energy for heating, cooling, and the drive energy of fans and pumps resulting in better control at a lower operational cost. Analysis of typical Nordic CAV and VAV systems indicates a potential for substantial sav-ings using new components and alternative system design. Component developments include more efficient motors, variable speed drives, pumps and fans as well as laminar flow heat exchangers and smart air-supply devices.

Air temperature and velocity are the two main factors affecting the thermal comfort indoors. These two values can be easily obtained using computational fluid dynamic (CFD) simulations together with the turbulence kinetic energy value. This paper evaluates methods of calculating thermal comfort indices using CFD. Simulated results are compared against experimental data measured in a purpose build full-scale model room. The results show that CFD data can reliably predict thermal comfort values.

This paper reports on a field investigation of the effect of screening on the induced flow rate in solar chimneys. The solar chimney considered here was a roof solar collector (RSC). It is composed of CPAC monier concrete tiles, an air gap and gypsum board. Two RSC units were integrated into the south-facing roof of a centre single room house of 25 m3 volume. Different types of screening were considered, namely: mosquito net, square net, metal grille and nylon filter.