House walls as passive solar collectors: An assessment

The gross solar energy falling on a typical house during the heating season is greater than the space heating requirement. Conventional solar collectors produce hot water, which is then used to meet the domestic hot water and space heating requirements of the house. Such collectors, however, are expensive, and it is only possible to use them to collect a small proportion of the available solar energy. This paper looks at an alternative approach of using the entire wall surface as a passive solar collector, by using an external layer of translucent insulation. Measurements and calculations are reported which show that a wall with a double-glazed outer layer would be expected to show a zero net heat loss over the heating season. This is not considered to be sufficient advantage to overcome the cost and other problems associated with the system.