The Purdue Conferences – the 25th International Compressor Engineering Conference, the 18th International Refrigeration and Air Conditioning Conference, and the sixth International High Performance Buildings Conference – were held during the five-day period spanning May 24 to 28, 2021 at Purdue University in Indiana State, the United States. Originally, the events were scheduled to be held in July 2020, but they were postponed until this year due to the pandemic and were held as online events. Here is an overview and report on the contents of the conferences.