The Schulich School of Engineering Block E was first constructed in 1964 and was the first of the blocks to be opened at the school. 54 years later, it was decided the block was due for a renovation, and mechanical design work was initiated in the summer of 2018. Aqua Air Systems scope of the job involved the design and delivery of a 45,000CFM stacked Energy Recovery Air Handling Unit, complete with supply/return fanwalls, hydronic cooling/heating coils, filters, and space for a future humidifer. The energy recovery device used on the job was a vertically stacked heat pipe, which uses a passive refrigerant cycle to transfer sensible heat between the exhaust and supply stream at an efficiency of 62%.