By Prof. Raymond Adomaitis, University of Maryland, USA.
The engineering design of reACT (resilient Adaptive Climate Technology) was driven by a set of functional requirements aimed at producing a house with an unprecedented combination of resiliency and adaptability. Future houses built using reACT’s design must be able to adapt to both the fixed location in which they are constructed as well as their dynamic environment that will change continuously over multiple timescales.
To maximize our measures of sustainability, reACT had to be able to use or recycle low-value resources that would otherwise go to waste. Adaptability means self-awareness, and so reACT needed to predict its state over a reasonable time horizon so that it can work with the homeowners on the best use of resources over the upcoming day, or to carry out those tasks autonomously.
The primary challenge to meeting these functional requirements is the complexity of integrating a large array of engineering subsystems while preserving our goal of a disentangled design to simplify inevitable future upgrades and modifications of reACT and its systems. We focused our engineering design process on model-based systems engineering concepts, making extensive use of both existing and in-house open-source simulation tools developed by our engineering team specifically for reACT.
As reACT’s design evolved, so did our simulation tools, transitioning from static, model-based engineering design to dynamic performance prediction. Having the ability to predict future states of the electrical and thermal energy, water, carbon, and other resource inventories in response to current weather forecasts using a physically based model of the house dynamics, reACT virtual came online nearly a year before construction of the physical manifestation of reACT prototype was complete, allowing the engineering team to explore the behavior of its major engineering subsystems both in College Park, MD as well as a number of other locations including the 2017 Solar Decathlon competition site in Denver, CO.
One outgrowth of studying the interplay between reACT’s engineering and architectural design elements was the development of four sustainability measures: four metrics that rigorously quantify different aspects of what it means to be sustainable with respect to energy, water, and food. More information on the continuing refinement of these metrics can be found at reactvirtual.eng.umd.edu.