Makes general suggestions for future buildings and their ventilation methods with the aim of creating improvements to avoid the faulty design of the 1960's with their high energy consumption. Considers the characteristics of natural ventilation and mechanical ventilation with respect to ventilation heat loss. Recommends the use of `ventilation on demand' for bathrooms, w.c.'s and kitchens using individual extract ventilation units for each room.
Considers the reasons for advocating mechanical domestic ventilation. Discusses which factors provide for an optimum climate in rooms. Treats room temperature, air movement in the occupied zone, air purity and humidity, odours, noise. Illustrates how mechanical ventilation should be arranged to provide correct indoor ventilation and the different ventilation principles involved: gravity ventilation, fan-assisted exhaust ventilation and supply and extract ventilation. Illustrates typical applications of these systems to single family houses.
The performance of an HVAC system's air-to-air energy recovery exchanger is defined primarily by the exchanger's effectiveness and pressure drop. The effectiveness is dependent on several parameters such as the supply and exhaust mass flow rates and the energy transfer characteristics of the device. Because of this combination, performance data must be established for each individual type of device.
Notes that as houses become tighter, adventitious ventilation decreases. Discusses attitudes to varying degrees of tightness. Explains introduction of the supply exhaust system which comprises air supply, air exhaust and heat recovery. Notes requirements for economic use of the system and relates installation costs to potential savings. Tabulates systems currently available in Sweden(December 1980)noting maximum air flow, position of heat exchanger and other factors.
Describes and discusses the principles, advantages and disadvantages of several types of air-to-air energy recovery devices, including the open and closed run-around systems; the heat pipe exchanger; the thermal wheel and the heat exchanger. Places emphasis on the potential energy savings in heating and cooling equipment and fuel costs by recovering energy from exhaust air before it is thrown away. Results indicate annual energy savings of up to 23% with even larger savings in the size of the heating and cooling equipment.
In order to investigate the possibilities of installing heat recovery equipment in old apartment houses, a large project has been started. There are 30,000 to 35,000 apartment houses in Finland with an average volume of6000-7000 cu.m. Possible savings from heat recovery in houses with mechanical exhaust are the transfer of heat to supply air using standard equipment and heat recovery from exhaust air using heat pumps.
After a general preliminary discussion of the meaning of "heat recovery" and possible systems for carrying it out, the author examines the possible different ways of transferring thermal energy from one fluid to another by means of an indirect heat exchanger. Air-to-air systems are in particular analyzed, examining the operating features of the various exchange types(rotating, fixed plate, multiple tower and finned tube exchangers). The paper concludes with a series of considerations on both energetic and economic aspects of thermal energy recovery.
Outlines necessary ventilation rates for an occupied room. Discusses natural ventilation of a room through openings in the ceiling. Discusses natural draught ventilation for single family houses, combined natural draught and mechanical ventilation, mechanical fresh air ventilation based on a central duct, fortuitous ventilation caused by air infiltration and leakage. Compares natural and mechanical ventilation. Considers supplyair systems for single family houses, warm air heating and possibilities for heat recovery.