Breeze Window Vent V2

A decentralised heat-recovery vent that cores through an outside wall in an afternoon, no ducting and no loft. A ceramic core stores the outgoing heat and hands it back to the incoming air, recovering around 88 percent - which is what makes airtight insulation and open windows stop being a contradiction. It runs from the air monitor's carbon dioxide reading, and reverses every seventy seconds so quietly that it is hard to tell it is on.