This paper discusses the potential for achieving an "energy-efficient" ventilation system by improving design procedures for natural ventilation. It considers ventilation requirements and the meaning of the term energy-efficient ventilation. Both of these topics are of fundamental importance to any design procedure. Natural and mechanical ventilation systems are discussed. This is done because natural ventilation is often compared unfavourably with purpose-built mechanical systems. It is argued that such comparisons can be misleading, unless all aspects are considered.

Measurements in a test room of 28.4 m3 located at the top of a 3-storey building have been made to determine ventilation rates of different natural ventilation systems. The systems under consideration were windows which are typical for residential buildings in Germany and various adjustable natural ventilation systems for installation in walls or window frames. The measurements take into account parameters such as inside/outside temperature differences, wind velocity and direction, opening position and location of thedifferent systems.

A study to assess personal exposure to respirable particles was conducted during January to March 1982 in Waterbury, Vermont. 48 non-smoking volunteers carried Harvard/EPRI personal samplers every other day for two weeks. 

An indoor/outdoor monitoring study was conducted during January to March 1982 in Waterbury, Vermont. Respirable particle measurements were made inside and outside 24 homes (all occupants were nonsmokers), 19 with wood-burning appliances and 5 without. Data were also obtained on seasonal air exchange rate, heating fuel consumption, and relevant home characteristics. Findings indicate that indoor particle levels are consistently higher than outdoor values regardless of heating fuel type.

The normally used equation for calculation of infiltration flow rates into a house is a power law of which the exponent n is normally assumed to be 0.66 but sometimes values of 0.5 or even 1 can be seen in the literature. In this paper the constant n is calculated assuming a non fully developed infiltration flow. The constant n will for this assumption take values between 0.67 and 0.77 if the slots where the flow takes place are long enough to get a flow close to a developed one.

The heat losses from small houses, due to transmission and ventilation, are estimated. The estimation i s based up on the house owness daily readings of electricity and water meters, and their notes on behaviour influencing the energy use. Consideration is taken to heat supply from insolation and from people. Hot water losses are calculated from use of water and use of household machinery. Besides the estimation of the heat losses, Q, wind and temperature in the area is registrated .

Natural and forced ventilation are directly and indirectly influenced by the pressure distribution around a building. Results of full-scale pressure measurements on a typical Swedish timber house are presented. The rate of air infiltration has been calculated by employing the values obtained from full-scale pressure distribution, air leakage characteristics and temperature differences. The results are compared with the actual ventilation obtained from tracer gas measurements.

The purpose of the project has been to determine the saving in energy obtained in the practical operation of an FTX-system -that is, a fan-controlled supply and exhaust ventilation system with heat recovery - compared to an F-system, which is solely a fancontrolled exhaust system. The investigation, carried out in a terrace-house district in Skellefteg, showed the following savings for the FTX-systems in comparison with the F-systems: in 1-storey houses (81 m², airtightness approx. 1): appr. 1000 kWh/year in 2-storey houses (99.5 m², airtightness approx. 3) : appr. 1250 kWk/year.

The investigation was divided into several parts: 1, measurements of a mechanical ventilation system, 2, calculation model for this system, 3, measurements of the air leakage of the facades of a flat and 4, calculation model for this flat.

Discusses the problems of designing ventilation for small houses. Small houses are considered to be far too elementary and there is no total view of the balance of energy and no regard for the interplay between different flows. Mechanical ventilation is often not controlled or inspected in small houses. Recommendations are: increased knowledge, differentiated requirements on ventilation, inspection of systems, definition of comfort criteria, changed conditions for heat recovery, and well-documented requirements for air tightness.