This paper presents ventilation systems with longitudinal counterflow spiral recuperators. Heat transfer losses in ventilation system can be reduced by increasing the length of the recuperator, but in this case pressure drops increase. These two losses determine exploitation costs. Taking into consideration the results of measurements and calculations the costs for capital expenditure and exploitation of ventilation systems are minimized.

This paper summarizes the work within the EU RESHYVENT project in regard to design parameters for the performance assessment of hybrid ventilation systems. A framework for performance assessment based on simulation was developed. Performance criteria were defined for air flows, indoor air quality, thermal comfort, acoustics, energy, and emissions.

In the scope of the EU supported project RESHYVENT, the possible integration of Renewable Energy Solutions (RES) into hybrid ventilation systems has been analysed. The focus has been on solar and wind applications to substitute the use of fossil fuel. The feasibility of the investigated options depends on the ventilation concept the RES is integrated into, the location of the building geographically, placement of the RES in the building and on the urban environment.

The purpose of this system is to provide one improved ventilation system allowing significant good indoor air quality, heating (and cooling) energy savings and acceptable thermal comfort on summer, by using especially renewable energy.This concept is based on sensors measuring relative humidity in bathroom and kitchen, occupancy in bedrooms and toilet, and agitation (i.e.

The aim of the project is to study, develop, build (prototype system) and evaluate an energy efficient demand controlled hybrid ventilation system for dwellings in a cold climate. Hybrid ventilation in a cold climate means a ventilation system with low pressure drops, which result in a minimisation of the mechanical energy for ventilation, and that natural driving forces can play an important role.

Within the EU RESHYVENT project four demand controlled ventilation systems have been developed, each one for a specific application field. The scientific support work for the industries has been reported in a number of documents. A number of these reports will be published as AIVC Technotes after completion of the project.

The purpose of this study was to assess indoor air quality as well as actual ventilation in renovated school classrooms. A typical naturally ventilated school building was chosen to install different air inlet units in identical classrooms. Later measurements of carbon dioxide concentrations, temperature, relative humidity and air velocity were carried out. Actual measured values were compared with Lithuanian and European standards. This study gives the evaluation of renovating process in the Lithuanian schools, which began in 1997.

School buildings in Flanders are quite old. They cause concern not only about energy efficiency but also about thermal comfort, indoor air quality, speech intelligibility and visual comfort. To evaluate the correctness of the concerns, energy consumption was monitored in 18 schools, while in each of them a classroom was selected for detailed measurements on comfort and indoor air quality. The results justify the concern. Energy consumption per pupil varies significantly, from low to really high.

Research has shown that highly efficient solar powered ceiling fans improve thermal comfort and potentially provide health benefits when air conditioning or conventional ceiling fans are not available, such as during the 2003 summer heat waves in Europe, and in many undeveloped areas of the world. Ceiling fans can improve the spatial effectiveness of heating, ventilation and air conditioning (HVAC) systems. They can reduce air conditioning energy use if occupants increase thermostat set-points and reduce frequency of operation, and if waste heat from the fan motor is minimized.

Approximatly over 90 percent of buildings in Poland are ventilated in a natural manner. Thescale of problems in the functioning of ventilation in our opinion is serious.In about 3 million apartments inhabitants use gas water heaters, burning fuel in an openchamber. Therefore in these types of apartments the use of mechanical exhaust ventilation isforbidden.Experiences in using mechanical ventilation is not always positive (frequent complaints aboutthe excessive noise of the installation and the high consumption of energy by the fans).