The 2015 REHVA Annual Conference was organized in Riga, Latvia on 8-9 May 2015 in cooperation with the AHGWTEL, the Association of Heat, Gas and Water Technology Engineers of Latvia. The main topic of the Conference was Advanced HVAC and Natural Gas Technologies. This event brought together leading experts from the international heating, ventilation and air condition community. The Conference in Riga gathered 150 people representing 22 countries to discuss HVAC novelties, standards and researches. The presentations are available online.