December_1970 — Page 31

The other sections of the frame- work above the basement are pre- fabricated and take the form of facade pillars which are tensioned into the location-cast construction. Between these pillars lie freely suspended fa- cade girders on which the facade slabs are hung. The light concrete roof is cast on a prefabricated framework plus the four inner pillars.

Another feature worth mentioning is the great care that was taken to make the rate of diffusion through the facade as small as possible. The risk, during the winter, of ice formation on the outside of the building with conse- quent damage would otherwise be

M

Volvo office interior at Torslanda

rather large when taking into consi- deration the relative humidity which the air conditioning unit provides. The roofing of the building is of wooden construction and placed approximate- ly 1m above the upper concrete joist construction and is clad with tarred paper and divided up into sections so as to lessen the fire risk.

The total amount of concrete used for the location-cast construction was approximately 16,000 cu.m. (K 300). The amount of reinforcing used, main- ly the Ks 60 type, was in the region of 1,000 tons. The prefabricated sections, including the facade units, weigh 12,000 tons. The steel girders men- tioned earlier weigh a total of 340

tons.

The areas in an open plan office are large. The ceiling and floors are design- ed to absorb sound. The sound level is so well balanced that disturbing sounds between working stations are avoided. Instead can be heard an un- disturbing, low frequency, hum of sound. Wall-to-wall carpeting, sound absorbing 'trellised' ceiling, movable screens and large plant groups combine

to dampen sound and provide a plea- sant working environment.

The air conditioning plant is ex- tremely complicated and enables the temperature and air humitity of each landscape to be kept at a constant level independent of the outer tem- perature. The main source of heat is provided by the lighting which has a calculated value of 600-700 lux. The capacity of the air conditioning plant is however, dimensioned for lux values of 1,000-1,200 units. The previously mentioned 'trellised' ceiling is designed as a cooling unit and absorbs up to two-thirds of the surplus heat. The temperature is kept at a constant

22-23 deg C (72-74 deg F) in the of fices. A central cooling plant feeds the system of pipes in the ceiling with water at a temperature of 12-18 deg C (54-65 deg F). Additional heating is not needed until the outside tempera- ture is lower than 15 deg C (+5 deg F).

Conditioned air is blown into the offices through spreaders in the trellis- ed ceiling, which was designed by Volvo's technicians. As the surplus of heat is absorbed by the cooling units in the ceiling the amount of air used for ventilation is limited to meet hy- gienic needs only and is totally draught free. The air is conditioned in a central unit and is blown into the offices at a controlled temperature which represents one-third of the ex- cess heat of the open plan office. The air is humidified, humidity being ap- proximately 40-50 per cent.

The large open surfaces enable each working station to be located where it can operate most functionally and where communication and contact is best. The 'in-line' type of office furni- ture arrangement is thus avoided. Be-

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