The Tower of London is to cut its air conditioning energy consumption by more than 20%, following an assessment to satisfy EU directive rules.

The assessment, completed by Darren Jones, head of consultancy Efficient Air, was done ahead of the 4 January deadline for inspecting air conditioning systems under EU’s Energy Performance in Buildings Directive. It looked at the air conditioning systems within the three-storey stone built Waterloo Block, which houses the Crown Jewels.

The Victorian building is open seven days a week and 3000m2 of its 5600m² is conditioned. The ground floor, which houses the Jewels, and first floor are conditioned by 10 AHUs. Top-floor offices are heated by radiators and the basement archive has another AHU. The building used over one million kWh of electricity and 950,000 kWh of gas in 2007.

Jones said the 22% energy cut would be around 429,500 kWhs for a saving of £22,370 a year and a CO2 reduction of 236 tonnes. The reduction will come through quick wins such as control modifications including time-schedules, better strategy on inlet dampers, improved lagging and reductions in fan speeds. No major capital investment is needed.

“Most organisations will have inspections done to comply with the forthcoming EU rules,” said Jones, who is also the CIBSE trainer for air conditioning inspections. “But the real issue should be to save money.”

The inspection was done under CIBSE’s technical memorandum TM44 which sets out the assessment schedule for complex systems over 250 kW. Simpler systems, over 12 kW, have until January 2011 before their first inspection. After this, inspections must be at least every five years.