Invisible.AC Limited St John's Innovation Centre Cowley Road, Cambridge CB4 0WS United Kingdom T +44(0)870 9619661 E [email protected] W www.invisible.ac Technical Guide TG2016.10 Born in the USA, refined in Cambridge, UK Invisible.AC is the 21st century incarnation of the high-velocity air heating system first invented in the USA after the second world war by jet propulsion engineer Calvin McCracken. McCracken recognised the way the thrust of a jet engine creates a swirling mixing in the surrounding air and he thought of applying the same principle to cooling and heating systems. He called the principle aspiration and demonstrated its ability to create much more uniform air temperature distribution than conventional low-velocity systems. Originally commercialized in the USA by Jet-Heet and since further developed by others in North America, high velocity systems grew to satisfy many domestic requirements, but have failed significantly to penetrate UK and European markets. Among the reasons for this failure to cross the Atlantic are: • High noise levels unacceptable to the more sophisticated European customer. • High energy consumption. • Problems in the transition from 60Hz to 50Hz mains supply. • Relatively unsophisticated control systems. • Questionable reliability in service. Now Invisible.AC, working from the world-renowned St John's Innovation Centre in Cambridge, has taken McCracken's original aspiration principle and has developed a full product range for European markets. Invisible.AC has applied its own experience in international requirements and standards to build systems which fully satisfy the cooling, ventilation and heating requirements of European markets. Invisible.AC products carry the CE mark, confirming that they meet all relevant EC Directives, some of the strictest technical specifications in the world. Design features which overcome the limitations of North American systems include the application of: • The latest European electronically-commutated (EC) blower motors for: - Inherently low noise and vibration. - Low power consumption. - Total controllability for optimum blower duty under all conditions. - Electromagnetic Compatibility (EMC) meeting stringent European Directives and fully CE marked. • High-efficiency aerodynamic backward-curved blower rotors. • Energy-efficient proven leak-free UK-manufactured heating/cooling coils with extralarge surface area for responsive thermal transfer. • Thorough and effective handling of condensate with reliable large-bore low maintenance drainage system. • Zoned temperature control modulating airflow not only via dampers but also via blower speed for maximum system energy efficiency and low noise. • Bottom-up acoustic design for comprehensive noise attenuation.

Invisible.AC Limited St John's Innovation Centre Cowley Road, Cambridge CB4 0WS United Kingdom T +44(0)870 9619661 E [email protected] W www.invisible.ac The new Invisible.AC system provides energy-efficient heating/cooling for both commercial and residential buildings, designed for simplified installation and quiet efficient operation. The system incorporates a high static pressure blower/heat exchanger unit, a modular plenum duct, and a kit of ready-insulated sound-attenuating flexible mini air ducts which together create a unique system to distribute the warmed/cooled air throughout the building....

Invisible.AC Limited St John’s Innovation Centre Cowley Road, Cambridge CB4 0WS United Kingdom The Invisible.AC system operates at typical air pressure of 370 Pa (1.5 in WG) in the plenum as compared to a conventional ventilation system’s 20- 40 Pa (0.1 to 0.15” WG). This high pressure technology facilitates the remarkably compact duct sizes and air velocity to create air aspiration in living and working spaces. There is no complicated duct sizing required because the system is designed around Invisible.AC pre-manufactured parts. All air distribution components are pre-insulated and pre-assembled....