FRESH ALL THE TIME

Press, Volume CXII, Issue 33034, 29 September 1972, Page 23

FRESH ALL THE TIME

When the audiences in the Town Hall auditorium are seated in great comfort at a performance they may not realise at once that their sense of wellbeing is contributed to in large degree by the freshness of the air in the huge space. This freshness is the result of the steady introduction of clean air at the right temperature and humidity. And this ventilat-

ing is not achieved by accident. Out of sight of the public, in concrete tunnels and engine rooms beneath the Town Hall complex is an elaborate heating and refrigerating system which has cost tens of thousands of dollars to install. Ducts, pipes, and wiring journey in their tunnels at the lower basement level, branching away like railway lines to ’ serve the whole complex. Enormous tanks store heated water until it is wanted; the fat, cladded pipes disappearing in the distance are so arranged that they can transfer

heat from one side of the building to the other, depending on the temperature gradient of the day. The result of all this machinery as far as the public is concerned is that in their seats they are cool and relaxed in hot weather, and warm on cold days. Above all, the air is fresh, and there are no draughts. This complete lack of stuffiness associated - with the old theatres of Christchurch is brought about by a system of air blowers high in the auditorium. The opportunity was taken to turn these delivery nacelles into individual platforms from which television crews could work.

The nacelles are interspersed with the acoustic panels and run round the fringe of the high ceiling.

The air delivery is, in fact, associated with the acoustic system —- without the blowers the acoustics would fall in efficiency.

Looking after this system, along with all the other mechanical services in the building is Cliff Wilson, aged 29, the maintenance superintendent.

Mr Wilson has an electrical technician with him on the permanent staff, John McKay, aged 30.

Among their tasks is the raising and lowering of the movable portions of the stages in both the auditorium and the James Hay Theatre.

Screw jacks driven by electricity supply the motivation; the stage aprons take eight minutes to raise or lower.

In the auditorium the two side aprons each have a lift of 15 tons (including their own weight), and the middle apron 22 tons. The one, central apron in the theatre has a lift of 27 tons.