Imagine living in a house that is so energy-efficient that you pay no utility bills.
Jack Achs hasn't achieved this goal yet, but he's getting close.
Achs and his wife, Molly, built a four-bedroom home in rural Port Byron in 2014-15 that Achs designed with a goal of looking like a "normal house," yet being totally energy-efficient.
"It was like my hobby," Achs said of working on the house. "It turned into a quest. I couldn't let it go."
He attended seminars and read "net zero home" publications backwards and forwards. He drew his own design (with construction drawings by an architect) and specified all the energy-efficient features. He expects his goal of net zero — in which the home will generate as much energy as it uses — to be met next year.
That is when he will install 10 solar array units on the house and 18 on his three-car garage, generating enough electricity to meet the needs of the totally electric home and then some.
"Then it will be free," he said of the functioning of his home. "I love free."
Achs is proud to say that the home is the first in the Quad-Cities to be built to three levels of energy qualifications: LEED, or Leadership in Energy and Environmental Design, a standard of the U.S. Green Building Council; Energy Star, set by the federal Environmental Protection Agency; and net zero, a generic term that means the building produces as much energy as it consumes.
The home contains so many forward-looking features that students from Jason Franzenberg's college-level Civil Engineering and Architecture class at Davenport's West High School, come to take tours.
Here is a closer look at some of the features.
• Prow design captures passive solar energy.
The home is designed and built to maximize the sun's free energy by facing directly south with large windows. This warms the home in winter because, with the orientation of the sun, the rays come right into the windows. And the effect is magnified by a special coating on the inside panes of the double-paned windows.
But in summer, when the sun has a different orientation, the home's prow shades the house. Light still comes in, but it's not as hot. (The prow is the home's roofline that extends 6 feet out from the house at its peak, tapering to two feet on either side.)
"It was amazing," Achs said of the solar gain in winter. "When you see something in a book, you ask yourself, 'Does this work?' It works!"
• SIPS construction makes home air- and water-tight.
Most homes in the Quad-City area are "stick-built." That means the frames are made of pieces of lumber and the roof support is made of trusses, a rigid framework of beams.
Achs' house is different, built with Structural Insulated Panels, or SIPs, that are pieces of foam sandwiched between panels of wood or, in the case of the foundation, foam sandwiched between four inches of concrete. Achs' were manufactured by a 35-year-old company called Enercept, based in Watertown, South Dakota, but there are others.
So, beginning at the basement, and continuing up through the sides and the roof, everything is made with SIPs. Large beams of engineered lumber provide the structure of the house.
"It came in two big semi trucks," Achs said of the panels required to build the house. A crane set the roof panels in place.
The result is a home that is air- and watertight, with the foam acting as a moisture barrier.
SIPs construction costs about 10 percent more than conventional, but will pay for itself in five years, Achs said.
Achs became aware of SIPs through the subdivision's developer, John Corelis, who learned of them through a manufacturer's display at a home show in Rock Island.
Corelis became convinced that the product is such a good construction alterantive that he became a representative. His daughter and son-in-law established a business called Supreme Services, of Coal Valley, that sells the product and is a certified builder. At this time, there are several SIPs builders in the Quad-Cities, Achs said.
• ERV guards against 'too tight' house.
Because the home is so tight, it must have an energy recovery ventilator, or ERV, that exchanges house air with fresh air from outside, running at a continuous rate of about 50 cubic feet per minute. The Achses manually increase this to 200 cubic feet per minute when they take showers, cook or do laundry, activities that put extra moisture into the air.
• Air-source heat pump heats, cools.
What keeps the home warm and cool? Warmth comes from the sun, augmented by a wood-burning fireplace with wood the Achses get from a friend and an air-source heat pump.
The latter is an electrically powered system that uses a compressor and "super-big condenser that works like a refrigerator in reverse to heat my house," he said. In the summer, it creates cool air, and in the winter it creates warm.
The one drawback is that it doesn't work when temperatures fall to 10 degrees or lower, which happens, on average, about 10 days per year in the Quad-Cities, Achs said.
For backup, there are electric coils, something like a space heater, that are required by code, because you can't build a house that doesn't heat itself. Coils are very inefficient, however, so the Achses depend instead on their 55,000 Btu fireplace.
(The reason the fireplace doesn't "count" as a heater is that banks lending money for a mortgage expect a normal heating system so the house is marketable, Achs said. Also, if you are incapacitated or there is a problem with the fireplace, you always need a backup plan, Achs said.)
Achs investigated geothermal for heating and cooling, but decided the air pump would work almost as well and be $10,000 cheaper.
In the year that the Achses have lived in their home, their MidAmerican bill for those times of year when heating/cooling needs are low, such as spring and fall, is about $50 per month.
When heating/cooling needs increase, such as winter and summer, their bill is $120 to $130 per month.
• Duct sealing adds to efficiency.
In a typical house, about 20 percent of warm or cool air is lost passing through the joints in the duct system. In fact, Achs' house failed the RESNET test for duct air loss. (RESNET is the Residential Energy Services Network, an independent, non-profit organization, that certifies home energy rating testers.)
While the joints in a typical house are sealed with tape or a mastic, a pasty cement, applied by hand with a brush, Achs had his ducts sprayed from the inside with an aerosol glue. This extra step took a half hour with a machine and cost $2,500, but he now there is zero leakage from the ducts.
• Rainwater is collected, diverted.
Rain water that runs off the south-facing house roof is collected into a pipe that goes to a 1,500-gallon cistern. The Achses hope to use this water for a future vegetable garden; their household water comes from a community well. Rain water from their north-facing roof goes to two rain gardens.
• Other efficiencies add up.
Energy Star appliances and LED light bulbs save on energy use and dual-flush toilets and low-flow faucets save on water use.
• House is 'an investment.'
Yes, the upfront costs were higher than a typical stick-built home. "Money for retirement went into this," Achs said. "This is an investment in our future."
He expects a return on investment between five and 10 years. "It can vary widely based on energy prices (cost of gas, electricity), our actual usage, and government incentives for the solar panels, which cost $28,000. The state of Illinois had a rebate, but it is suspended due to the budget crisis," he said.