Would you leave the heat off in the middle of a rural Minnesota winter, with temperatures nearing 32 degrees below zero Fahrenheit?
For most homeowners, the answer would be "No," besides freezing the humans inside, the pipes would surely burst. But Paul and Lynn Hunt are far from typical. Their ultra-efficient home in Pine River, Minnesota, is the centerpiece of their 70-acre "laboratory" in "abundant resilient communities," called the Hunt Utilities Group (HUG), as described in a NY Times blog.
When the Hunts faced that question two years ago, they decided to take a chance and turn off the heating system before going out of town. When they returned two days later, the interior of their new, ultra-efficient home was still a comfortable 66 degrees.
Besides the super-insulated house, the HUG campus features an administrative building constructed out of straw bales and cob, an adobe-like material made from clay and other reinforcing materials. A 14,000-square-foot manufacturing space (called ManiSpace) has a built-in greenhouse and a 76-panel glazed hot air solar array.
Their vision: grow communities where homes operate according to net-zero principles, not just from an energy standpoint but also waste management and sustainable food production.
"We are developing practical ways to grow communities that feed themselves; where the houses heat themselves; and the nutrients are recycled. In the process, our 70-acre campus is becoming a destination point for sustainable living," says HUG on its website.
HUG is testing new sewer designs, new windows and green building materials. There are green roofs and a wind turbine, which contributes modestly to energy production. Fruits and vegetables are growing in a three-acre garden that produced its first harvest last fall.
The best practices learned at HUG will be shared through two non-profits that are sited there, the Rural Renewable Energy Alliance, which focuses on making solar more accessible, and Happy Dancing Turtle, which promotes sustainable living through educational programs. One focus is building a culturally sensitive community prototype for Indian reservations.
"The whole place is a lab," Paul Hunt told The New York Times. "We need to know what works and what doesn’t so the next design gets better."
Unique to the campus is the so-called HUGnet, a network of more than 1,000 sensors that collects data about temperature, wind speed, air pressure and humidity every 5-15 minutes. That data can be accessed by anyone via the Internet.
So far, ManiSpace is their biggest success. The building stays warm by using a system that integrates underground heat exchange, geothermal heat pumps and solar.
Warm air from the greenhouse is directed up to the roof's solar panels where it's heated to 140 degrees Fahrenheit. Then it's funneled underground to be stored for future use.
Here's their website: