The AIHTC and Begell House have agreed to establish the IHTC Digital Library (IDL). The IDL is an online archival library featured with interactive web interface and advanced search engine for the use of active researchers and engineers. It is composed of the past and future Proceedings of the International Heat Transfer Conferences under the auspices of the AIHTC. Thus, all papers of IHTC-15 are uploaded and included in the IDL.