Liberty’s beautiful, mock tudor department store was devoid of air conditioning until the 21st Century, when it was realised that air conditioning was essential. The consulting engineers, Dwyer Consulting Ltd, designed a bespoke, high velocity, high pressure system, comprising two roof mounted air handling units, each weighing around eight tonnes, supplying conditioned air through a system of fourteen vertical, high velocity riser ducts, terminating in some 160 purpose built, oval shaped high velocity terminal devices, blending in with the interior. The system was approved by English Heritage.

The air handling units supply variable air volumes up to some 40 metres cubed per second, incorporating free cooling, when available, and with a twin screw Aermec water chiller, provide some 800 kilowatts of cooling during summer.

The roof installation required precision craning, due to the presence of temporary contractors’ buildings on gantries, the air handling units being craned up on special steel cradles to assist in the positioning of each section.