Early in January 2013, a computer room in the Bryant Building used by the Faculty of Science and Technology at Anglia Ruskin University in Cambridge had its aging air conditioning system replaced with two Monodraught Cool-phase low energy cooling and ventilation systems fitted discreetly within the existing ceiling void.
In an effort to reduce its energy consumption, Anglia Ruskin University is keen to explore low energy alternatives to conventional air conditioning technologies and as a result, two Monodraught Cool-phase systems were specified to serve the Science & Technology classroom, replacing the existing end-of-life air conditioning system that provided comfort cooling but no ventilation. The Cool-phase systems provide intelligently controlled ventilation that naturally cools the area through the use of phase change material housed in thermal battery modules. The systems maintain thermally comfortable conditions and good air quality levels throughout the year.
Following the award of the contract, Monodraught’s design engineers first carried out dynamic thermal modelling, the results of which determined that two Cool‑phase systems (8KWhr) were required to ventilate and cool the space and, as is often the case with retrofit projects, the installation was rather challenging.
At the Anglia Ruskin site the conventional wall louvre assembly for supply and exhaust air also had to be reconfigured due to the existing building construction, but the design team engineered a solution that utilised a roof mounted supply and exhaust system to serve the two Cool-phase units. Similarly, the installation of both Cool-phase systems was also carried out by Monodraught’s installation team in to prevent disruption to teaching commitments.
Commenting on the selection of the Cool-phase systems, Andy Lefley, assistant director of building services, estates & facilities at the University says the university was grateful to the department for allowing the trial in the Bryant Room and will be monitoring the results closely to gauge the impact.
“If the trial is successful, the Estates & Facilities team will consider a range of further applications across the Cambridge and Peterborough campuses.” He says.
Each Cool-phase system continually monitors and records temperature, CO2 concentration and energy usage. Data collected the computer room between January 25th and September 2nd 2013 show very impressive results.
The average daily temperatures for the Science & Technology computer room clearly demonstrating that the Cool-phase systems have consistently maintained the internal temperature well within a comfortable band and that while internal temperatures have exceeded 25°C, 28°C and 32°C during the data logging period, the Cool-phase systems have maintained an ideal temperature of less than 25°C within the room for 97% of the occupied hours across the thirty-one week period. At no point has the room exceeded either 28°C or 32°C – a level of performance that far exceeds the target overheating criteria stipulated by both CIBSE Guide A and BB101.
The typical background or atmospheric CO2concentration is recognized as approximately 400 parts per million (ppm). In education facilities CO2 levels should ideally remain below 1500 ppm, with levels above 1500 ppm considered high. The CO2concentration in Room 016, where the two Cool-phase units are installed, is consistently maintained below the threshold level.
But perhaps the most impressive result shows that the combined energy consumption of the two Cool-phase systems was 197.6 KWh of electricity across the thirty-one week data logging period. Assuming a standard electricity tariff of 0.11£/KWh, this amounts to total energy costs of £21.74, or just 70p a week, for both Cool‑phase units.
Commenting on the choice of Cool-phase for the project, Andy Lefley, assistant director of building services, estates & facilities said; “I am very excited by this technology and by the opportunity to improve student comfort without increasing the energy burden to Anglia Ruskin University. The results achieved show that the solution has complied with the overheating and air quality criteria, keeping temperatures and CO2 concentrations within acceptable levels. This has been achieved with very low energy usage and equally low running and maintenance costs.”
Commenting for Monodraught, Cool-phase development manager John Curley says the two systems have clearly met the design criteria and specification requested by the client, adding: “Both Cool-phase systems delivered comfort cooling and maintained internal temperatures within an acceptable band, whilst providing fresh air to ensure that CO2 levels were maintained within acceptable boundaries.”
Further information and videos are available at http://www.cool-phase.net
Cool-phase® is a registered trademark owned by Monodraught Limited.
In the current climate of soaring energy prices and the fear of global warming, increasing attention is being focused on Monodraught’s natural ventilation, natural daylighting and natural cooling product ranges.
Monodraught has always sought to invent, explore and develop innovative technologies that harness the wind and sun. Products include Windcatchers, Sunpipes, Suncatchers, Sola-Vents, Sola-Boosts and Cool-Phase.