You might be thinking of the work led by Professor Shanhui Fan @ Stanford some years back; https://news.stanford.edu/2017/09/04/sending-excess-heat-sky/ https:

You might be thinking of the work led by Professor Shanhui Fan @ Stanford some years back; https://news.stanford.edu/2017/09/04/sending-excess-heat-sky/ https://news.stanford.edu/2017/09/04/sending-excess-heat-sky... This is being commercialized, but I don't know how successful it has been to date. https://www.skycoolsystems.com/ https://www.skycoolsystems.com/