Feasibility study of novel integrated aerogel solutions
District heating networks are commonly addressed in the literature as one of the most effective solutions for decreasing the greenhouse gas emissions from the building sector. These systems require high investments which are returned through the heat sales. Due to the changed climate conditions and building renovation policies, heat demand in the future could decrease, prolonging the investment return period. The main scope of this paper is to assess the feasibility of using the heat demand
... the heat demand -outdoor temperature function for heat demand forecast. The district of Alvalade, located in Lisbon (Portugal), was used as a case study. The district is consisted of 665 buildings that vary in both construction period and typology. Three weather scenarios (low, medium, high) and three district renovation scenarios were developed (shallow, intermediate, deep). To estimate the error, obtained heat demand values were compared with results from a dynamic heat demand model, previously developed and validated by the authors. The results showed that when only weather change is considered, the margin of error could be acceptable for some applications (the error in annual demand was lower than 20% for all weather scenarios considered). However, after introducing renovation scenarios, the error value increased up to 59.5% (depending on the weather and renovation scenarios combination considered). The value of slope coefficient increased on average within the range of 3.8% up to 8% per decade, that corresponds to the decrease in the number of heating hours of 22-139h during the heating season (depending on the combination of weather and renovation scenarios considered). On the other hand, function intercept increased for 7.8-12.7% per decade (depending on the coupled scenarios). The values suggested could be used to modify the function parameters for the scenarios considered, and improve the accuracy of heat demand estimations. Abstract The market share for fibre reinforced aerogel insulation materials is expected to increase as production costs are lowered, and in this context, the development of layered products with integrated aerogel is highly interesting. The effect of uniaxial compression and humidity on the thermal conductivity of commercially available aerogel insulation blankets were measured in order to assess the feasibility of integrating aerogel blankets with other building components. The thermal performance under uniaxial compression was measured by compressing commercially available aerogel blanket materials in a heat flow meter apparatus. Up to 11.5 % decrease in apparent thermal conductivity was observed at a compressive strain of 16 %, corresponding to an applied stress of approximately 22 kPa. The thermal insulation properties of the aerogel insulation blankets remained excellent within the range of compressive stress investigated in this study (up to about 40 kPa), making aerogel integration highly interesting for building components that will be used under compression. However, a 32 % increase in thermal conductivity was observed upon exposure to an atmosphere of 95 % relative humidity (RH). Thus, in order to widen the range of application for fibre reinforced aerogel insulation materials, further investigations should be conducted to understand and improve their tolerance to moisture.