Victorian building refurb achieves Excellent rating

UK: A former Victorian warehouse in London has been equipped with a chiller/heatpump, thermal store and a concealed Carrier air conditioning system as part of a major refurbishment and extension. 

Originally built as a headquarters and warehouse for lead and glass merchant George Farmiloe & Sons, the Grade-II-listed Farmiloe Building includes a spectacular glazed atrium with exposed wrought-iron beams and panelled offices. As an example of Victorian architecture, it is often used as a location for film and fashion shoots. 

The works required the conversion of the existing five-storey building and the creation of a new six-storey extension to accommodate retail units on the ground floor, a basement office and ancillary spaces and five upper floors of offices.

It also involved back-to-brick renovation of the original 150-year-old building, restoration of the iconic Victorian façade. The heating and cooling system was designed to be fully concealed or boxed-in, matching the high quality finish of the building.

Comfort cooling for the 5,600m² site uses a combination of Carrier Idrofan 42NZE four-pipe fan coil units, exposed thermal mass, and cast in air ducts supplying passively heated and cooled air to each fan coil unit. 

The building had to be connected to the local district heating network to adhere to London Plan requirements. Consultant Skelly & Couch ensured that the design was robust enough to work passively, using natural ventilation and exposed thermal mass, while still providing an integrated low carbon cooling and mechanical ventilation system to meet the commercial brief.

To keep relatively high floor-to-ceiling heights in the new extension, the ducts were cast into the post-tensioned concrete slab. 

The heat-recovery chillers installed collect the casual and solar gains from the spaces and store them in phase-change vessels. 

The thermal store, supplied by Phase Change Material Products Ltd, provides approximately 1,500 kWh +13ºC and is cooled at night using lower cost of energy or when the ambient temperature is cooler, increasing the COP of the heat pump. The thermal store is then used during day peak periods to drive the cooing systems instead of using the heat pump for cooling or top up the cooling loads while the heat is running. This waste heat recovery/free cooling concept drastically reduces the amount of energy used by the HVAC system and means that the building has little need for heat from the district heating network. 

“The system had to be designed to operate using the temperature ranges delivered by the part heat-pump-based water system and the phase change coolth store, so that the carbon reductions outlined in the London Climate Change Plan could be achieved, without the need for renewables,” said consultant Mark Skelly.

The design enabled the building to achieve a BREEAM rating of Excellent.