Revisiting radiant cooling systems from a resiliency perspective: A preliminary study

Radiant heating and cooling systems have been proven to be an energy-efficient and resource-effective heating and cooling solution for buildings. One of the key features of radiant systems is the possibility of activating and controlling the thermal mass. This feature allows spreading the heat removal from indoor spaces over a longer period, compared to more conventional systems e.g., air-conditioning. This feature of radiant systems could be particularly beneficial under heat wave and power outage events. The present study investigated the performance of Thermally Active Building Systems (TABS) and Packaged Terminal Air Conditioners (PTAC) in terms of controlling indoor temperatures under future typical weather files, and under future heat wave and power outage events. The simulations were carried out for Copenhagen, Denmark. For future typical meteorological years, TABS performed better with heavyweight construction, but PTAC had little influence from the construction type. During heat waves, both systems were able to maintain a generally comfortable temperature range but with a slightly overall higher temperature. When a heat wave and power outage occurred at the same time, the cases with heavyweight construction had lower temperatures regardless of the cooling system. With TABS and heavyweight construction, the room temperature was maintained within the comfort range of 26°C for 16 hours after the heat wave and power outage started. After the power outage was over, TABS with heavyweight construction was able to reduce the room temperature to the comfort condition of 26°C faster than PTAC by 18 – 71 hours. Results obtained from this initial set of simulations suggest TABS could be a better solution than PTAC in terms of its resiliency to heat waves and power outages although both systems could have different advantages depending on the operation, building type and building use.