Thermosyphoning air panels (TAPs) were installed as part of the refurb
ishment of a school building in south-east England. Design, constructi
on, and operation are described. Their long-term thermal performance w
as monitored extensively. Annual contributions to the heating load wer
e 1970 kWh for the 23 m2 of south-facing TAPs, and 498 kWh for the 27.
3 m2 of east-facing TAPs during the 1989/90 heating season. The econom
ic viability of the installation is discussed.