Applicability of aerogel as a nano-insulator for thermal regulation of residential building envelope

Abstract

Thermal regulation and thermal control in building is best achieved when the building’s envelope is given particular attention. This is usually done by improving the thermal mass of the building. However, the drawback for increasing thermal mass is that it comes with a proportional increase in weight. This is however countered with the introduction of aerogel which is a good thermal insulator.
Aerogel can be used in many building envelope applications with limited space as an effective remedy for intense thermal bridging. Its high flexibility makes it a promising insulation candidate for buildings. The rig-set up is a cavity wall was built using commercial aerated blocks, the blocks were laid and sealed with silicon between the joints, and two separate built-up walls placed parallel to one
another with a cavity between them of 35mm. This wall is placed as one face of the rig cell, and the other five sides consisted of an insulated material of half inch plywood and 50mm Celotex® board and a heat mat was laid. The internal dimensions of the cell measures 1200 x 1200 x 1200. Readings taken and results show that with the application of the aerogel blanket in the cavity with no application of heat from the heat mat, temperature was constant at an average of 10.5°C, but when there was heat mat was turned on, the temperature was a basic sine curve peaking at 60°C and dropping to 20°C, at constant intervals, thereby giving the indication that as the heat tries to penetrate, the aerogel barrier repels the heat and makes it to drop through a difference (ΔT) of 40°C. However, when there is no aerogel in the cavity, and heat applied, the behaviour of the temperature is slightly unpredictable and more heat passes through the wall, peaking at 82°C, which is 20°C higher than when there was a buffer of aerogel. The lowest temperature recorded is 42°C which shows how effective the aerogel insulation is, as less heat is dissipated into the cell when the aerogel is in the cavity.