How do we engineer our homes to be functional,
reliable, and environmentally-active? The SCIArc/Caltech Team developed five systems
that address these concerns in CHIP. We start with our energy source. Our computer models
show the photovoltaic system reliably generates enough energy to go netzero in almost all
weather conditions. Tigo module maximizers can connect panels on different slopes using
only one inverter, increasing the overall power output of the array while reducing cost.
We combined HVAC and hot water into one efficient system and manage them through our customized
algorithms. Our HVAC system draws heat from the house to heat a thermal storage tank.
The tank preheats the hot water before the water flows to a heat pump, and then out to
the taps. The fan coil units filter and circulate air within the house. The Energy Recovery
Ventilator provides a constant supply of fresh air to meet ASHRAE recommendations. The whole-house
fan quickly exhausts stale air from the house. The home’s upward slope promotes natural ventilation
by letting hot air escape out the north window as cool air enters from the patio area. When
it rains, water runs down the roof and falls into a storage tank beneath the deck. The
computing system collects weather forecast data and predicts when to send water from
the tank to drip emitters that irrigate plants. We reuse the greywater from the laundry machine
to water plants, as well. We combine our customized software with affordable off-the-shelf hardware,
so the smart home can automatically save energy. The house predicts energy use and generation
to make intelligent decisions for the homeowner. Window shades close automatically to keep
out sunlight, and smart occupancy sensors will turn off all the lights if they detect
that no one’s home. The homeowner can intuitively manage energy use through two interfaces.
One interface uses the XBox Kinect’s 3-D camera to read a person’s gesture and location,
so he or she can control lights and media. The second interface is an iPAD app that can
display real-time energy use and lets the homeowner easily control lighting, TV, and
appliances. Finally, we need to maintain the internal climate, but we do it our way: we
put CHIP’s insulation outside the structural walls and wrap them in a weatherproof vinyl
skin. This prevents heat from escaping through uninsulated wood while the skin acts as an
effective radiant barrier. The vinyl skin resists deterioration
and can be easily maintained. Intelligent design and engineering can meet the growing
need for solarpowered housing. CHIP generates enough electricity from its solar panels to
power more than two typical California homes in a year, and it also consumes two-thirds
less energy than those ordinary homes. Shouldn’t all our homes be doing this?