The evolution of data tools that support improved energy performance of buildings follows the broader development of data management and processing, a field which has expanded rapidly in recent years. This article reviews the various types of applications currently available.
The first part of this article focused on software-only tools. Among other things, we observed how new applications can evolve hierarchically, e.g. the use of web-based tools for the generation of Energy Performance Certificates (EPCs) facilitates the development of aggregate databases of EPCs and these in turn support realistic models of energy consumption for entire cities and regions.
This second part looks at state of the art applications which also integrate hardware tools. Due to the cutting edge nature of such applications, fewer commercial options may be widely available. Major contracting firms may also use custom-developed solutions, integrated with their other tools and processes for design and construction.
In order to better understand the concepts and possibilities, we'll consider first some of the available options for automatic data collection, and then how these are applied in modelling and other areas.
Automatic data collection
The most obvious source of energy data for a building or dwelling is its mains power meter. Automatic meter reading (AMR) allows recording of power consumption across entire areas for the generation of utility bills. Contemporary smart meters go further, by registering consumption of electric energy at intervals of an hour or less, as well as recording power outages and power quality issues. These meters also enable two-way communication with the central system, in effect responding to data requests in real time.
Buildings equipped internally with energy monitors or 'smart plugs' can provide much more detailed data on consumption. Such data is usually used on the premises, i.e. in a Building Management System (BMS) / Building Automation System (BAS). These systems will nowadays often connect to the internet –either for remote management or for technical support– and in consequence it becomes possible to centrally monitor how power is used internally in many buildings, whole blocks and neighbourhoods, etc.
Intelen's DiG platform is an example of this local/central approach: it allows energy users to monitor their own consumption –in full detail if they have installed smart plugs– and for energy utilities to gain insights into their clients' consumption patterns.
In a different context, energy inspectors can use thermal imaging to identify parts of the building envelope that would benefit from improved insulation or airtightness. It is now possible to use 'location aware' thermal imaging devices which record all information required to accurately match each image to the corresponding surface as depicted in the building plans. In addition, regular geotagged photos can be used to document specific aspects of the building, including quality of the works, e.g. installation of insulation and corrections of thermal bridges.
Drones can also be employed to automatically scan a full building, both externally and internally, with thermal or visual cameras. Although such applications are still at the pilot stage, they are indicative of the potential unleashed by contemporary hardware-software integration. The costs of such applications continue to fall with the emergence of products such as Google's Project Tango framework and consumer-grade mobile devices and drones.
Part 1 of this article mentioned how consumers can use their smartphones to identify products via bar codes to automatically access relevant information. Similar technology can be used to identify building products and (packaged) materials during construction, and to access their energy performance characteristics.
Making sense of the information
The sheer quantity of data collected through the above methods necessitates new information processing and representation approaches, such as Building Information Modelling (BIM).
A Building Information Model can be thought of as a virtual prototype of a building – or a site, an infrastructure system or even a city. The model integrates all relevant aspects of the building itself, e.g. building elements, materials, systems, networks etc., even water pressure in plumbing systems and external conditions such as wind forces and solar light and heat. BIM can then be used to simulate the building's behaviour in full breadth and depth, facilitating decision making during the design process. BIM's usefulness continues beyond the building's delivery, as it can also support operation and maintenance.
Typically, the BIM data structure is composed of several layers integrated with the building drawings. Correspondingly, most popular computer aided design platforms are linked to compatible BIM tools, e.g. Autodesk has developed Revit as a BIM platform supporting AutoCAD. Given the extended range of building aspects covered by BIM, there may be different tools available to simulate and explore specific aspects. However, most tools should be able to use the same integrated BIM files as reference.
An example of a BIM tool focused on energy performance is the cloud-based gEnergy, developed on the EnergyPlus platform. It helps users to apply best practice in their buildings designs, providing dynamic simulation and detailed data of their proposed building’s performance.
Following the design stage, the BIM can be used as a full reference during construction. Real data collected on site, such as product and material specifications, and construction documentation, can enable direct comparison of the building performance as designed and built.
Integration via Augmented Reality (AR)
Identification of deviations between simulated and actual building energy performance is the subject of Energy Performance Augmented Reality (EPAR). Users collect large numbers of digital and thermal imagery from a building under inspection using a single thermal camera. Through an image-based reconstruction process, actual 3D spatio-thermal models are automatically generated and are superimposed with expected building energy performance models generated using Computational Fluid Dynamics (CFD) analysis. The outcomes are EPAR models which visualise designed and actual performance in a common 3D environment.
The Horizon 2020 research project INSITER aims to leverage the energy efficiency potential of buildings based on prefabricated components from design to construction, refurbishment and maintenance. The use of prefabricated components in construction offers several advantages, but a significant part of the energy performance still relies on the quality of the build on site. INSITER therefore seeks to extend the use of BIM for standardised inspection and commissioning protocols, involving all actors in the value chain.
The INSITER project also advances Augmented Reality (AR) as an intuitive and cost-efficient approach to inspection. In fact, AR probably represents the most direct and effective integration of BIM (or other design framework) and the real world data. What AR does is to place virtual layers over the world with geographic specificity ensuring a good fit: an inspector equipped with an AR viewer –which can be a simple smartphone– may point it to a wall of a building and see superimposed cabling, water piping, thermal images, specific measurements, etc. The saying "a picture is worth a thousand words" can be paraphrased here as "an image can represent a thousand numbers".
Fraunhofer Centre for Sustainable Energy Systems (CSE)
Potential applications of BIM and AR extend beyond construction, to operation and maintenance. Within this context, the US National Renewable Energy Laboratory has developed an Augmented Reality Building Operations Tool (ARBOT) to support technicians with minimal training and experience in diagnostics, commissioning, and maintenance. ARBOT uses a mobile device (e.g a smartphone) and a server linked to a Building Management System to provide operating data to the technician at the location of a possible fault. The operator takes a geotagged photo of the equipment under investigation; the photo is transmitted to the server, the system identifies the equipment and sends back an image with actionable guidance at the point of failure or poor performance. The technician is then able to use the mobile device to perform diagnostics or maintenance on the equipment, order a replacement, or store a reminder to perform an operational check.
The shape of things to come
A number of applications that are made possible by contemporary tools and processes are highlighted in the Horizon 2020 project BUILT2SPEC. The project covers several aspects of a building’s specification and performance, including energy efficiency, and includes numerous interesting tools and approaches: 3D and imagery tools, BIM, smart building components, energy efficiency quality checks, indoor air quality tools, airtightness testing tools with air-pulse checks, thermal imaging tools and acoustic tools.
In the introduction of the first part of this article we made reference to some of the trends that have made sophisticated data tools possible and affordable for consumers, namely 'always connected', the integration of advanced technologies, crowdsourcing and the interconnection of reference databases. Such trends and developments will also continue to support the evolution of data tools available to building professionals, as elaborated throughout the article and demonstrated by the BUILT2SPEC project among others. The only ‘limit’ is imagination.
