105068FREEHEAT: Revolutionising the viability of natural ventilation through heat recoveryClosedCollaborative R&DInnovate UK"Free Running Buildings Limited targets the first cost-effective high-performance passive ventilation system with heat recovery, with the aim of radically reducing the energy, carbon dioxide and cost-burden of achieving legislative requirements for indoor-air-quality in public-sector buildings: namely schools, healthcare facilities and leisure centres. Health, performance and productivity of occupants in these buildings is significantly impacted by failure to maintain acceptable levels of carbon dioxide, pollutant/allergens and temperature. Adequately ventilating these buildings requires the inside-air to be fully refreshed every 6-10 minutes, with existing approaches to ventilation and heating yielding over 60% of energy-use and running-costs in these sectors. To address the huge energy and cost-demands of current technologies such as air-conditioning or mechanical ventilation systems, adoption of wind-tower-based passive ventilation is growing. However, the requirement to constantly and rapidly raise the inlet air temperature, when the weather outside is below a comfortable ambient temperature, stimulates a significant space-heating requirement in many market territories. This requirement fundamentally restricts the zero-energy operating window and corresponding viability of this approach in many scenarios. In response, and working collaboratively with the University of Sheffield (Building Energy Group and the Advanced Manufacturing Research Centre), Free Running Buildings now aims to further develop their core technologies for wind-driven passive ventilation and heat-exchange to realise FREEHEAT. Targeting a 5-degree Celsius thermal gain using novel heat pipe designs and configurations to capture exhaust energy and pre-heat inlet air to realise a step-change in passive heat-recovery-efficiency and system weight, integrating this technology into their proprietary modular flat-pack assembly also catalyses new retrofit capability for existing passive ventilation systems."