The product, which has been installed in thousands of homes across Europe, uses a specially formulated phase change material to store large amounts of energy from renewable and other sources and release it as heat to deliver hot water and space heating as needed. The PCM is sodium acetate trihydrate-based with a patented formulation giving a melt point of 58 degrees Celsius.
In independent testing conducted by ZAE Bayern, the PCM was successfully melted and solidified in a UniQ heat battery for 10,000 cycles. At the end of the test, no significant differences in stored thermal energy capacity were found between the cycled samples and an uncycled sample of the PCM. The product, which also passed leak testing, earned the association's highest level of certification, Grade A.
Over 3,000 UniQ units are now in service, with Sunamp projecting a tenfold growth in sales next year. The quality mark will be featured on Sunamp’s website and in other marketing materials, UniQ manuals and product labels.
“We are delighted that our thermally charged UniQ product range of heat batteries has been awarded a globally recognized mark of quality,” said Kate Fisher, Ph.D., a materials integration scientist at Sunamp, which is based in Edinburgh, Scotland. “RAL certification is a huge accolade and cements Sunamp’s position as world leaders at the forefront of the technology.”
The RAL Quality Association PCM was established in 2004 to develop standards for the PCM industry. Members include Axiotherm, Microtek Laboratories, Rubitherm, Croda Europe, va-Q-tec, PCM Technology, Global-Systems Europe, Sasol, Sunamp, Pluss Advanced Technologies and PureTemp LLC.
Members and non-members alike can submit their products to the association for independent testing and earn the RAL Quality Mark. To qualify for the mark, products and materials must meet standards for energy storage capacity and phase transition temperature and stability, as defined in RAL-GZ 896.
“I am delighted that more and more products with PCM technology can be awarded the RAL Quality Mark as meaningful and transparent proof of quality and longevity,” said Stefan Thomann, the association’s managing director. “The great thing about Sunamp´s UniQ heat batteries is that they can be installed and used in homes very easily and save a lot of energy costs and carbon emissions immediately. The fact that they passed more than 10,000 cycles make sure that users will be able to profit from these benefits for decades.”