Background

Geoclima developed a project for two brand-new exclusive buildings in the City of Westminster. The buildings are very high end residential apartments by Abell and Cleland with £1m value each and will be located on different sides of the road. The buildings include luxurious apartment, gym, sauna facilities, pool and business rooms and suites.

The buildings are designed to meet high sustainability standards and specifically to reach the level 4 of the Code for Sustainable Homes.

For this project Geoclima’s team worked closely with Cool-Therm and contractor Briggs and Forrester.

Purposes

For this project, Geoclima had to design a solution providing cooling for both buildings. This required very high cooling capacity: 1.8 MW.

In addition to high cooling capacity, the cooling plant had to meet specific requirements. High energy efficiency is paramount in general and to reaching level 4 of the Code for Sustainable Homes. The air conditioning plant was also required to be designed for installation in restricted space, in order to maximise  floor space and occupation. Another fundamental requirement set by the client was to provide very quiet operation, due to the luxury residential nature of the building.

Project

This was a very challenging project, as it required a multi-element approach in order to provide the best solution able to meet all end user’s requirements. In particular the necessity to provide both high capacity and very low noise in restricted space at the same time, was a very stimulating challenge for our engineering team.

For this project we designed and developed two 900 kW air cooled Turbomiser chillers, providing 1.8 MW of total cooling capacity.

High energy efficiency is reached by using Turbomiser technology, which reduces energy consumption and requires low start-up current.

Turbomiser technology has been further customized in a unique configuration in order to meet all specific requirements concerning space restriction and very low noise.

As for space restriction, we designed an extra lower framework beneath the chillers containing pipework, isolations valves, cable tray to be installed in the base of the chillers. In this way the plant footprint is dramatically reduced and, at the same time, it is still possible to easily access to unit and components for maintenance operations.

The main challenging request was noise limit of 51dBA at 10m. 51dBA is a very low limit considering that Turbomiser chillers in “standard” configuration reach 63dBA at 10m, which is considered quiet operation. To reach the required limits, it was necessary to re-think the configuration of the chiller and add some extra sound attenuation measures.

The major measure is the addition of “silencers”, acoustic attenuation towers on the top of each condenser fan, that means 16 towers per unit. These towers are 1.6m high and 1m large.

In addition to this special measure, units are equipped with sound insulation boxes for the Turbocor compressors. This results in sound reduction of 6 – 7dBA.

Finally, refrigerant discharge lines to condenser are lined with lead insulation, in order to reduce vibration and noise.

All these measure together make the plant achieve the required 51dBA at 10m, as demonstrated by tests performed in our test center prior shipment and installation.

Results

The project was very challenging as it required the customization of the plant not only in terms of performance but also in terms of structural issues. The two Turbomiser air cooled chillers with silencers were installed in 2015 on the roof the building but are meant to be commissioned in early 2016.