Soon, files won’t be gathering dust at Writers’ Buildings, they’ll just go cold.

The hot seat of Bengal’s rulers at Dalhousie is aiming to turn cool in about 18 months when a central air-conditioning system costing Rs 10 crore is expected to be installed.

The air-conditioning plant will use water from Laldighi instead of the conventional gas-based system, which is said to affect the ozone layer. Most air-conditioning systems in India and China use the cheap refrigerant HCFC-22, already banned in Europe. Developing countries are allowed to use it until 2040.

“We have made a proposal to introduce central air-conditioning at Writers’. It only needs a few clearances before we roll out the project,” PWD minister Kshiti Goswami told Metro.

The project, to be implemented by Goswami’s department, will cover the entire building, barring the corridors in the non-protected portion. The corridors in the protected zones will be shielded with layered glasses to ensure insulation.

The air-conditioning plant will be at the base of the parking plaza opposite Writers’. Water pumped out from Laldighi will be condensed in the chilling plant and piped out to the cooling units on the floors of the building through an underground duct.

“The chilled water will reach either the cooling units in every room or to the air-handling unit, which will cool a few rooms together or a specific zone. The system will be in operation day and night, as may be required, and the water will be recycled,” said S.K. Kundu, who drafted the blueprint before retiring as chief engineer (electrical) of the PWD.

“The project can be fully implemented in 18 months from the day of commissioning,” Kundu said.

Only 15 per cent of Writers’ Buildings has air-conditioning now, which means the vast majority of the 7,500-strong workforce of the 40-odd departments makes do with fans and khaskhas that hang from the giant windows of the building. Before these, there were the pankha-pullers in the sixties who saved the babus from getting too hot under the collar.

Engineers of the PWD contemplated a centralised air-conditioning system for Writers’ last summer, when at least eight departments requested financial allotments to buy air-conditioners. The proposal was discussed at the secretary level in November and the blueprint drafted after the PWD minister verbally okayed it.

Kundu said the central air-conditioning system could reduce Writers’ electricity bill by at least 40 per cent. The government spends over Rs 30,000 a day only on electricity consumed by the air-conditioners installed in the VIP rooms.