ABSTRACT

World wide concern about the depletion of our energy resurces led in 1975 to the decision by the ICHMT-executive to organize a Symposium on Energy conservation in Dubrovnik in 1977. The energy crises of 1973 initiated many studies on energy use in the industrialized, high energy consuming countries. In retrospect the crisis in 1973, followed by a smaller one in 1980 were political crises. Essentially there was no real shortage in fossil fuel supply. Declining oil prices in the '80's have shown this. However there is no doubt that the fossil fuel reserves we are using are time - limited. The need for energy conservation is still undisputable. It is interesting to note that since 1973 energy consumption per unit of GNP has been reduced: by 33% in Japan, 25% in the USA and 15% in Europe. This is the result of the energy conservation measures in these countries.
The topic chosen for the 1977 ICHMT Symposium was energy use for heating and cooling buildings: both residential and commercial. This was done because, about one third of primary energy consumption is in that area. The main topics of the Symposium were:

- Heat and moisture transport in building materials.
- Ventilation and air movements.
- Modelling of energy requirements for buildings.
- New techniques.
- Solar energy

A few advances since 1977 will be noted here.