This work explores responsive hydrophilic polymers for convergent functions of climate control with architectural material systems. In buildings, the transition across exterior and interior space occurs through the envelope, which is an enclosure system that mediates heat, light, air and moisture transfer functions. Conventional building envelopes are typically constructed to form a barrier that insulates and hermetically separates outdoor and indoor conditions. The dynamic environmental responses of superporous intelligent hydrogels are shown to be beneficial at the interior layer of a double-skin glazing system for building envelope applications. If the hydrogels are integral to the building envelope system, then various environmental functions (such as natural daylighting, heat transfer, airflow and moisture control) can be achieved through integrated actuators to result in improved building energy performance.
The composite embodiments emulate bio-analytical functions when embedded microbore-tube water channels serve as actuators for swelling and deswelling kinetics respectively. Each prototype is conceived in response to hot-arid climate contexts. The prototype presented here is a lightweight ventilation cooling and daylighting system. Initial prototypes are inserted into an environmental test-bed that is consequently divided into two chambers to represent an outdoor and indoor condition. The input chamber includes controllable heat and light elements that affect the dynamics of the hydrogel system. The output chamber on the opposite side of the prototype division includes temperature, humidity and photo sensors that are connected to an Arduino board for data collection. Dependent upon the environmental conditions of chamber two, a control program actuates small hydro-pump to saturate the gels with water.
The initial results provide correlations between mechanical (elasticity) and thermal (conductivity) properties. Current work in progress includes documentation of average rates for sorption-desorption kinetics and correlations between saturation loading and visible transmittance. The physical test data will also be integrated into building-scale energy performance simulations and hygrothermal transfer numerical analysis for building envelope compositions. The embedded material logic of the hydrogel is exploited in an architectural configuration for a convergence of prior building mechanical system and building envelope functions. The current work demonstrates a highly promising application of soft-skin membranes for much needed reductions in energy consumption within the building sector.