Night time air cooling
In 2003 we invented the night time air cooler which delivers colder air than the ambient.
The solar radiation absorber is designed to very well exchange heat through radiation; at night it loses heat through radiation towards the sky which is very cold (can be 600C colder than the atmosphere). In the summer nights we cool the warm ambient air by drawing it through the colder solar radiation absorber. This way we alleviate the summer night discomfort.
However, this cooling effect is smaller than the heating that can be obtained during the day.
We use this advantage of our solar collectors to extend their use through the warmer months. The diagram below shows the year-round usefulness of our solar air heaters in a temperate climate: