Paper Conference

Proceedings of BSA Conference 2022: Fifth Conference of IBPSA-Italy


Modeling Energy Consumption in a Single-Family House in South Tyrol: Comparison Between Hemp Concrete and Clay Bricks

Silvia Ricciuti, Irene Lara-Ibeas, Annamaria Belleri, Francesco Babich

Abstract: The built environment generates nearly 40 % of annual global CO2 emissions. To reduce these emissions, alternative materials able to store CO2 have started to be used in the construction sector. In the case of hemp concrete, part of this storage occurs during its service life leading to a potential decrease of indoor CO2 levels. Assuming that CO2 is used to control ventilation rates in certain buildings, the use of this material might lead to lower ventilation requirements and, thus, reduced energy consumption. The aim of this work was to develop an energy model including the CO2 sequestration capability of hemp concrete to estimate the potential energy savings derived from its use in a typical residential building in South Tyrol with CO2-based demand controlled ventilation. This result was later compared with the energy consumption of the same building made of clay bricks and the influence of air infiltration on indoor CO2 levels was also evaluated. The results obtained from the simulations showed that indoor CO2 levels were always lower in the hemp concrete buildings compared to the building made of clay bricks. However, in hemp concrete buildings with high air infiltration rates, the effect of the CO2 absorption by the hemp concrete wall might be negligible. The energy required for the mechanical ventilation to maintain the CO2 levels under the 1200 ppm threshold was estimated to be 0.28, 0.02 and 0.01 kWh/(m 2 yr), for the clay brick with low infiltration, hemp concrete houses with low and high air infiltration, respectively. Therefore, the operation of hemp concrete buildings with CO2-based demand-controlled ventilation may have a slightly lower energy consumption as well as environmental impact than the equivalent clay brick buildings.
Pages: 341 - 348