This paper investigates quantitatively the energy conservation achieved by balanced ventilation with heat recovery and upstream ground heat exchanger. The investigations were conducted on an occupied single-family house equipped with such a balanced ventilation system. The heat recovery unit of this system consists of a plate-type heatexchanger with a downstream small air-to-air heat pump. In addition this house is equipped with a ground heat exchanger.
The occupant's behavior with respect to window opening may greatly affect the ventilation system, the energy consumption orland the indoor air quality. In order to quantify the magnitude of opening times, many surveys have focused on climatic parameters and concluded to the temporal correlation between the timelength of opening and the outside temperature or the solar irradiation. In this paper, we study the influence of sociological and technical parameters on the average time of opening during the winter.
Airtightness deficiencies of building envelopes and weaknesses in the ventilation systems can disrupt the operation of heating and ventilation systems. This can lead to an insufficient level of air quality and higher energy consumptions. In order to assess the performances of buildings and ventilation systems, CSTB has designed and developed different experimental devices for field testing. In a first step, an equipment was produced to measure the envelope air leakage. This apparatus is mainly used for research purposes.
In well insulated buildings the ventilation heat is sometimes higher than the heat losses by transmission. For a air change rate of 0,8 per hour the specific heat flux must be calculated with 25 w/m², so heat recovery can save some energy. In all considerations the saving in the heating system must be compared with the additional energy for the fans, because this energy is of a higher quality. To optimize the heat recovery system, the different designs of the heat exchanger, the annual running hours and the annual hours for heat recovery must be taken into account.
The greenhouse effect is one of those topics in environmental politics which are currently worldwide at stake. There are several national concepts aiming at the diminution of CO2-emission in order to lessen the greenhouse effect. One of these concepts is the CO2-reduction programme of the Federal Republic of Germany. With this resolution, passed on November 7th, 1990, Germany's Federal Government aims high: national carbondioxide emission is to be cut back by 25 per cent by the year 2005.
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