A CHIP off the old block
If you think that building a net-zero energy home means sacrificing all the smarts required by today’s modern living standards, think again.
The Compact Hyper-Insulated Prototype (CHIP) is proof that not only can you retain advanced automation technology, but it can also be the pivotal factor in attaining complete energy efficiency.
CHIP was designed by a team of students from two US-based schools: Southern California Institute of Architecture (SCI-Arc) and California Institute of Technology (Caltech) as part of the US Department of Energy Solar Decathlon 2011 competition.
The 10 day contest challenges 20 teams of college and graduate students from around the world to build highly efficient, solar-powered, net-zero houses, and judges them on aspects such as energy efficiency, architectural quality and market appeal. The teams spend around two years designing and building their entries at their respective institutions, before the houses are packed up and shipped across to Washington D.C. for the competition.
Upon first look, the most striking feature of CHIP is its quilted exterior. As well as providing the home with a unique architectural quality, it serves as an efficient and cost-effective insulation method. By separating the structural members from the insulating layer and wrapping the assembly in a flexible vinyl membrane, it gives CHIP an exterior envelope with the extremely high insulation level needed for a netzero house.
Additional climate optimisation is provided through the HVAC system. In cooling mode, the outdoor air condenser extracts heat from indoor air, and the waste heat is used to produce hot water. A thermal storage tank also stores this heat until it is needed.
As you step inside the home, it becomes apparent that it adopts a ‘less is more’ ethic; the modest space is optimised through interchangeable cabinets and stackable furniture, and the home is divided into a series of platforms, to progress through a homeowner’s daily tasks: downhill in the morning as they sleep, groom, dress, eat, live, and vice versa in the evening.
To power this smart living area, a 42 panel photovoltaic (PV) system is in place, using panels from Hanwha Solar. Caltech chemical engineering junior Andrew Gong was in charge of the home’s electrical connections and played a major part in the design of this solar power system.
“The competition had rules associated with it, which helped us figure out how long we would have to run devices for. Once we realised how much electricity was needed to power this, we used the US Department of Energy’s program, System Advisor Model, to create a computer simulation of potential systems and work out which would be most efficient,” Andrew says.
“Unfortunately, during the competition, it rained for around five or six days, so we produced around 127kWh and consumed 120kWh, but this still gave us a slight positive over the course of the week.”
The solar power system also employs the Tigo Energy Maximizer technology, which allows a solar array to produce the most energy possible regardless of orientation or shading issues.
“Normally you’ll have a little bit of variation in the output of each panel because of production quality, lean, shade or tilt, but these units let you attach panels in any configuration and maximise the output of each panel. This definitely improved our efficiency.
“This also allows us to communicate with a central computer and analyse the data and performance of each individual panel.”
However, it is through the clever customisation of the Control4 control system, which allows the home to come into its own.
Caltech mechanical engineering undergraduate Cole Hershkowitz led the CHIP computing systems team and says the group wanted to educate consumers on how automation technology is intuitive and easy to interact with, despite the prevalence of “fancy, complex home automation systems on the market”.
“We wanted to show people that home automation is not just a glorified remote control. Once you have these smarts, it can make your life more comfortable and more energy efficient,” he says.
Nearly all the house’s devices are linked to the Control4 system via a Zigbee network, allowing full control of the efficient LED lighting, home theatre, shades and other mechanical systems – either via smart phone or through a custom iPad app.
“The App displays a simple floor plan allowing you to activate and deactivate devices. If you click and hold on an item, you get to get more advanced features – so with the TV you initiate its remote control.
“Unlike other clunky touch screen menus which you might have to dig deep into before you can control anything, with this, a home owner can easily flip lights on and off, see the state of devices and view the energy draw of the house.”
To allow even more power of the house’s features, a custom software package uses an Xbox 360 Kinect to control devices using natural gestures such as pointing and waving.
“The Kinect has a 3D camera and can see you, your body and where your hands and head are. With our software, you can point at lights to turn them on, or point at a shade to draw it down,” Cole says.
“It also has intelligent learning algorithms in it, so if you always turn lights off in the same location, next time you’re in that spot it will turn it off automatically.”
Many other tasks in the home are carried out automatically – lighting is programmed to turn on slowly in the morning, to awake occupants naturally, and lights are turned off when a homeowner leaves a room. Further, the projector will automatically lower if a Blu-ray disc is inserted, and shades will be closed if too much sunlight is detected; improving viewing, or preventing the home from over-heating and activating the HVAC system.
The home also has water conservation firmly in mind, with another Control4 driver enabled to determine whether to trigger the irrigation system, based on the previous day’s weather and upcoming forecasts. These intelligent solutions were also expanded to maximise the team’s performance in the competition. For example, points were gained for carrying out certain tasks, such as laundry, but points were lost for energy consumption.
“We built an algorithm which used future weather predictions to create a thermal and solar model of the house. This would predict how we would perform over the next days of the competition, telling us if we would have surplus energy or not. Based on that, it could advise us whether running the dryer would justify the amount of points lost for energy consumption.”
CHIP ranked from first to third in the majority of the Decathlon’s categories, coming in at sixth place overall. However, Cole says the team was unlucky not to have finished higher.
“It was a little bit disappointing because we jumped from around fourteenth place on the second day, to third towards the end. Unfortunately on the final day the category was ‘market appeal’ and we dropped down the rankings. The judges loved the advanced control and engineering of the home, but I think the architecture was a bit too forward-thinking for them.
“Overall though, we’re really happy with what we achieved, and everybody learned a lot.”