The application of heat pumps to ventilation heat recovery in domestic houses is considered. It is shown that the most effective system is a combination of heat pump and heat recovery unit; a plate heat exchanger is the type commonly used. Such units are now commercially available, and can provide heat at a lower cost per kilowatt hour than the Economy 7 tariff. The performance of several units is presented, and seasonal running costs have been computed for a house equivalent to the Capenhurst low energy house design.
R-2000 Homes have specific requirements for mechanical ventilation, usually incorporating heat recovery ventilators. Performance testing was carried out on 12 residential heat recovery ventilators in 1984, representing the range of equipment
Describes evaluation of two integrated heating and ventilating systems, one a modified warm air system and the other a modified mechanical ventilation system. From the technical viewpoint the systems were found to be efficient. However it remains to be seen whether mechanical ventilation systems with heat recovery including flue heat recovery can be justified in economic terms.
Discusses the installation of mechanical ventilation with heat recovery in residential buildings. The various ventilation strategies are summarized for both blocks of flats and single houses. Building components and guidelines are described.
Various ventilation systems have been examined in unoccupied test houses under natural climatic conditions. Two identical test houses were used to enable comparison of the effects of different ventilating systems on the air change rate and heat consumption. The systems examined were natural ventilating devices placed in the window area and centralized and decentralized mechanical systems. With the decentralized systems, draughts were generally unavoidable. Heat recovery from exhaust air at an air change rate of 1.0 h-1 gave a measured heat consumption saving of about 16 per cent.
The increasing number of heat recovery devices in ventilation systems for residential buildings leads to the necessity for a standard test procedure. In this paper the main examination criteria are stated. The test facilities todetermine the efficiencies and the air leakage of heat recovery devices are specified. The test procedure used is described. Results from different heat recovery units indicate the suitability of the developed test equipment.
Three blocks of flats on the outskirts of Worms were equipped with a mechanical ventilation system with heat recovery, a mechanical ventilation system, and stack assisted natural ventilation, respectively. Building description, air quality, air change rate, draught protection, noise level, energy balance, individual heating costs, efficiency calculations, planning and installation experience and user behaviour were studied. Systems with heat recovery were found to permit a 15-20 per cent reduction of heat consumption. User behaviour in opening windows is dependent on habit.
Reports on use of supply and exhaust ventilation with heat recovery in prefabricated houses and multi-storey buildings. In thermal super insulated buildings the system can supply heat demand down to an outside temperature of5 degrees C: additional electric storage heating is used below thistemperature. The ventilation system operates at an air change rate of approximately 0.7 per hour in the following way: exhaust air from the kitchen, bathroom, and WC, supply air to the living and bedrooms. It is combined with an air to air heat pump.
In newly built well insulated houses, a wind of 4 m/s will produce an air change rate of almost 0.3 h-1. However it is considered necessary to obtain air change rates of 0.7 h-1.
Dynamic insulation is a means of reducing building heat losses to near zero without the use of massive thermal insulation. It relies on recycling the heat conducted through the fabric or reducing the temperature gradient by means of a suitable heat transport fluid - usually air and sometimes water. Describes research and experience in Sweden and France. In Sweden, some 80,000 m2 of roofs (mostly of single storey sheeted structures) use the contraflow system of dynamic insulation and there have been a few experimental installations in the housing sector.
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