Grant: Idea to Innovation

The emerging geothermal industry has shown rapid growth related to the construction of green buildings. Designing geothermal heat pump systems used for heating and cooling of commercial, institutional and industrial buildings requires an in situ assessment of the subsurface thermal properties. The conventional testing method, namely thermal response test, can only be used to measure the subsurface thermal conductivity. The subsurface heat capacity is evaluated from the available literature and associated to the geological materials identified while drilling without conducting any field experiments or direct in situ measurements. This can result in uncertainty when designing a geothermal system and calculating the length of the ground heat exchangers, which is the most expensive component of a ground-coupled heat pump. This project aims at developing a prototype and verifying a new test method to evaluate the subsurface heat capacity. The prototype will be built for pre-commercial tests, based on oscillating heat injection and recent development of thermal response tests with a heating cable. Results are expected to reduce uncertainty about the ground thermal properties to better constrain the design of geothermal systems and decrease their installation cost. *