Windcatcher Zero natural ventilation with heat recovery uses an integrated counterflow heat exchanger and a robust intelligent control strategy. The adaptive controls sense air quality in real time and seamlessly switch between energy efficient modes: natural, mechanical, and heat recovery ventilation. An integrated ‘Air to Air’ core mounted heat exchanger within the natural ventilation system automatically varies between ventilation modes. Integrated solar PV panels run boost ventilation fans, and ventilation requirements are achieved efficiently without consuming electricity even during periods of very low wind speed. A volume control damper, inlet air filters and datalogging are provided as standard. With Windcatcher Zero smaller and fewer heat emitters are necessary within the occupied spaces and overall boiler loads are reduced.