Innovative, Cost Effective and Sustainable – A First for UK Building Cooling

 

Cowlin Construction’s 4West project at University of Bath will benefit from a new concrete core cooling system.  Designed by German air conditioning experts Kiefer, who have installed over 1,000,000ft² of the Concrete Cool System in Germany over the past 5 years, this is the first installation of its kind in the UK.

 

The Kiefer Concrete Core Cooling System (CONCRETECOOL - provided by LTi Advanced Systems Technology Ltd) uses air in a thermodynamic process to cool the concrete ceilings in a building, and has no visible pipes and no water.

 

To install the system prefabricated cooling coils were laid in the statically neutral zone of the concrete ceiling between the upper and lower layers of structural steel.  The embedded cooling pipes then act to cool the concrete without the need for draughty air circulation or water pipes, by drawing in cool outdoor air and exhausting air which has absorbed sensible heat from the concrete. As well as providing cost effective cooling utilising outdoor air also provides the required fresh air needed to meet the ventilation criteria, in accordance with Building Regulations.

 

This innovative system is cost effective in installation and low in energy use, between 25 & 35 kWhrs/m².  The system runs mainly on Free Cooling, taking in air at ambient temperatures, which accounts for up to 80% of cooling.  As the overnight temperatures are generally in the order of 10°C lower than the daytime, utilising an efficient night time free cooling cycle contributes to lowering the operating costs.  This also means that there is a reduced carbon impact as the system utilises the most efficient generating plant during the night, reducing the impact on the distribution mains and eventually the requirement to build additional generating plant.

 

The system is almost self regulating and variation–free with temperatures maintained at around 21C, for example: at a ceiling temperature of 22C the air entering the cooling tube at 12C is heated up to the temperature of the displacement air of 21C.

 

The building, which will house seminar rooms, new classrooms, staff rooms and the vice chancellor’s office is built over four and six floors and is due for completion in March 2010.  The cooling system was one of a range of sustainability design features which means the building has a BREEAM Excellent Rating.  It also played a large part in internal design; where most air conditioning systems would place restrictions on internal wall positions, this system allows for complete freedom and maximum use of space, which in this instance means that different room sizes could be housed on separate floors of the building.

 

Andy Webb, Project Manager for Cowlin Construction, commented: “Two months before we started construction of the concrete frame we invited a representative from LTi to give a presentation to the construction team so we could understand the system, how it was to be installed and make a plan that would ensure the system was fully integrated into the works.  Everything arrived from Germany as planned, with all components manufactured and pre-cut at the plant.  At the outset of the project we allowed 31 days to carry out this operation, but because of the ease of installation we reduced this to fifteen days.  All the usual fears when using a new product were unfounded; it has proved to be very robust and user-friendly.

 

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