The paper examines the extent to which user's intervention may compromise the therrmal performance of small sunspaces in the context of a Solar Energy Demonstration Project at Easthall in Glasgow (55°52'N), which was monitored from September 1992 to May 1994. Results indicate a tendency to close down windows etc. late in autumn and open them up early in spring relative to heat demand. In other words a user – driven energy load due to ventilation is higher in autumn and spring than in the central winter period.

In a way most heat pumps recover or reclaim heat energy for space heating and cooling, water heating or process heating. In the building sector, the natural heat sources which heat pumps transfer to useful heat, such as outside air, the ground, ground water and sea/lake/river water are in fact all heat sources that consist of solar heat and cannot be directly used for heating due to their temperature. Hence, one can argue that heat pumps which use these sources are (solar) heat-recovery devices.

Demand controlled ventilation systems can be used to minimise energy consumption whilst maintaining satisfactory levels of indoor air quality (IAQ). As an alternative to C02 sensors IAQ sensors (based on Taguchi mixed gas sensors) can be used to infer levels of IAQ. This Technical Note provides details of a series of laboratory and site tests to determine the performance of a range of IAQ sensors.

To investigate the effect of ventilation on indoor radon (222Rn), simultaneous measurements of radon concentrations and air change rates were made in 117 Danish naturally ventilated slab-on-grade houses built during the period 1984-1989. Radon measurements (based on CR-39 alpha-track detectors) and air change rate measurements (based on the perfluorocarbon tracer technique; PFT) were in the ranges 12-620 Bq m-3 and 0.16--0.96 h-1, respectively. Estimates of radon entry rates on the basis of such time-averaged results are presented and the associated uncertainty is discussed.