Live, Learn, Grow: Stevens to Build Smart House That Teaches Homeowners to Live Greener

4/29/2013

A team of students representing nearly every academic discipline at Stevens is joining forces to build “Ecohabit”, an intelligent, energy-efficient and sustainable home. 

The project is part of the Solar Decathlon, a biannual competition hosted by the U.S. Department of Energy in which 20 university teams from around the globe compete to design, build and operate the most energy-efficient solar home within budget and building limits. In 2011, the first year that Stevens competed, Stevens’ “Empowerhouse” won awards in two categories – affordability and hot water – and is now home to a working mother of three in an inner-city neighborhood in Washington, D.C.

This year’s entry – created by more than five dozen students with expertise in engineering, design, architecture and computer science – will not only demonstrate that solar power is an affordable and reliable home energy source, but will also teach its inhabitants to live more sustainably. Each component of the house features intelligence, which contributes to the home’s efficiency, affordability and sustainability.

“All of the houses in the competition are zero net-energy, but Ecohabit stands out because it is a ‘smart house’ that gives the occupants total control of their home,” said Alexis Moore, a computer science major. “Our desire is for the homeowner to learn how to become friendlier with the environment. The systems all work together to make suggestions to help the occupants make adjustments in their lifestyles and live greener.”

Solar power is of course one important aspect of the house, working to both conserve and produce energy. Ecohabit’s roof will be constructed with an incredibly new technology – DOW POWERHOUSE™ solar shingles – which were donated by team corporate sponsor Dow Chemical Company. The shingles include a fully integrated photovoltaic (PV) system that converts all of the sun’s rays into electricity to power the house.

“Ecohabit will be the only house in the competition with solar shingles instead of solar panels,” said Tim Weeks, an electrical engineering major. “They are much smaller and less obtrusive than solar panels, which will give us an aesthetic advantage over the competition.”

Another cutting-edge feature is the “phase-change materials,” or PCMs, which will be built into the interior walls of the house. The PCMs absorb, store and ultimately release heat, enabling the house to harness the sun’s energy during the day and release it into the house at night to maintain a constant temperature.

The house also includes a rainwater harvesting system which collects 100 percent of the rainfall and uses it irrigate and hydrate a “green roof” and “green wall” – which are covered in real plants, flowers and vegetation native to Southern California – as well as a regular outdoor garden. The green roof and green wall will act as extra insulation, storing heat and even reducing pollution and serving as a soundproof barrier.

“What is unique about Ecohabit’s rainwater harvesting system is that all of the components – from the collection tank to the plumbing system to green wall, green roof and garden – are integrated together,” said Erin Hopson, a civil engineering major. “First rain drains onto the green roof to bring water and nutrients to those plants, and then any excess gets pumped into the green wall, and finally to the garden.”

And virtually everything about the HVAC system is innovative.

One technology, the condensate misting system, reduces energy usage by collecting condensate to use for cooling.

“Usually, all of the cold condensation that builds up on air conditioner pipes is just dumped,” said Spencer English, a mechanical engineering major. “We’re storing that condensate and will spray it onto the outdoor unit of the HVAC system to keep it cool, which increases the load capability and energy efficiency.”

There is also the desiccant system which uses a special humidity-absorbing material to control the humidity level, ensuring maximum comfort while using very little energy. Typically, energy-sucking air conditioners are used to lower humidity.

“Air conditioning takes up a lot of electricity,” said Dan Tipaldo, an electrical engineering major. “The desiccant system is a low energy system to remove humidity and let the air conditioner focus on cooling.”

The heating system also includes a recirculating heat pump which transfers heat from the ambient air into the hot water heater.

“On a sunny day, the pump saves a lot of energy,” said English. “The sun is basically a constant source of energy for the hot water heater.”

This innovation also preserves water resources by ensuring the water is already warm when you turn on the faucet to take a shower or wash your hands.

“Instead of turning on the faucet and waiting for the water to get warm, you hit a button to start recirculating hot water through the plumbing system,” said English. “The button changes color to notify you when there is hot water ready at the tap.”

What’s more, special sensors in the bathroom will know when someone walks in and automatically turn on the pump. The house will then alert the user when the water is warm and ready for use.

But perhaps the most innovative technological advancement in Ecohabit is what makes it “smart” – the central control system which will receive data from sensors located throughout the house, adjust certain systems to ensure the most energy-efficient usage, and even provide feedback to inhabitants on important factors like weather patterns, temperature, occupancy levels and power usage so they can learn to live more sustainably.

The system begins with custom sensors in every outlet which will collect a constant stream of data on temperature, humidity, light intensity and other environmental elements. Through a low-power wireless communications protocol, the data will be aggregated by a central monitor, which will dispense it in such a way as to help inhabitants make smart and sustainable decisions and maintain an energy-efficient lifestyle.

The monitor will provide a complete understanding of how much energy is being used by a certain appliance or system at a certain time of day in a certain area of the house. Based on the data, it will make recommendations to the occupant on actions they should take – “lower the thermostat;” “turn the air conditioner off;” “flip off the lights in the bedroom.”

It even collects local weather data to alert the occupant of coming temperature changes – i.e. “it will be 80 degrees in one hour; turn the air conditioner on low.”

And the occupant can make adjustments directly at the monitor, or from anywhere in the house using smart phone connected to the wireless system.

“The information we will collect will be incredibly granular,” said Assaf Kipnis, a cybersecurity major. “You’ll be able to tell how much power is being used by every single appliance and system.”

“There are companies out there that make certain solitary functions of a house intelligent, but it is rare to find a house where all of the smart functions are integrated and controlled by the same central system,” added Maunil Sanghavi, a computer science major.

In addition to utilizing energy-efficient technologies, the unique layout of Ecohabit also makes it an optimal space for sustainable living. The unique L-shape creates as spacious as possible a house for the small size requirements of the Solar Decathlon competition – under 1,000 square feet – and a modular furniture system and a “flex” room that can serve as an office or a second bedroom will allow occupants to reconfigure the rooms as their needs change.

Ecohabit also utilizes the outdoors in a variety of ways. Exterior glass walls will fold open to both provide natural ventilation and an expanded living space, and two large covered decks also extend the interior space.

“Our biggest design challenge is making the roof big enough for the solar shingles,” said John Ivanoff, a product architecture major. “Our roof will be very expansive – we call it a massive ‘wing’ – and it juts out past the core of the house. We are using the areas under those sections of the roof as small outdoor decks or porches that serve as an extension of the living room or as a barbeque area. It’s perfect for Southern California weather, because those outdoor spaces can be used all year long.”

Ivanoff said the architecture and design team is extremely focused on improving the marketability, usability and consumer appeal of the house.

“We want this to be somewhere people can actually see themselves living and fitting in and calling home,” he said.

All in all, Ecohabit redefines the traditional relationship between the home and its occupants, allowing both to learn from one another and ultimately creating a more sustainable, energy-efficient way of life. With all of the energy and water savings made possible by the vast array of advanced technologies embedded into the infrastructure, Ecohabit is also an incredibly affordable living space with utility bills that will hardly compare to the average home.

Following months of designing and planning, construction of Ecohabit is now underway on a construction site in the parking lot of Stevens’ Griffith Building along the Hudson River, overlooking the New York City skyline. After being shipped to Irvine, Cali. for the Solar Decathlon in October 2013, the house will eventually become home to a deserving war veteran in Southern California.