MADISON – Finding ways to use energy more efficiently has become a priority in the fight against climate change.
Madison Rotary members were introduced to a more climate-friendly way of living — the “passive house” — by Mike Bianchi, a Madison resident who lives on Loanka Way, during a meeting on Thursday, Jan. 20.
A “passive house,” Bianchi explained, is a specific building design that aims to reduce the building’s carbon footprint through its insulation, windows, reduced thermal bridge, airtightness, ventilation, and dependence on solar energy.
He started his presentation with the measures he used to make his own house a “passive house”.
The house was originally built in 1958, used natural gas for heat and hot water, and had a small amount of insulation in the walls and ceilings. Bianchi and his wife, Joan Maccari, mostly used electrical appliances and had an attic fan.
He said he decided to research energy-efficient renovation solutions and came across the concept of “passive house”.
“The name comes from the initial goal, which was to have a house that got all its energy from the environment and didn’t need to be connected to external energy sources like electricity and gas. and stuff like that,” he said.
Bianchi said that creating a Passive House reduces home energy costs by around 75%.
Her home now uses geothermal heat pumps to provide heat and cooling and thick insulation. Old appliances have been replaced with energy-efficient ones, like a heat-pump clothes dryer and an induction cooker, which heats pots and pans, not the surface they sit on.
Despite adding an additional 2,000 square feet to the home, Bianchi said the home’s energy use has dropped from 55 megawatt hours of electricity and gas in 2015 to just 10 megawatt hours of electricity and no gas. in 2020.
“Almost all of our electricity came from solar panels,” Bianchi said.
Bianchi explained that there are five basic principles for making a passive house.
The first is thermal insulation, which involves installing thick layers of insulation with air and vapor control layers.
Layers of insulation help maintain a consistent temperature throughout the house, as there is little room for air to escape.
“The result is you have this huge thermal mass that’s hard to get away from,” Bianchi said.
The second principle is to install thicker windows to prevent heat from escaping.
Bianchi said the best windows to use are four-paned. They have an outer layer and an inner layer of glass as well as two plastic films and are filled with argon to increase window efficiency.
The inner film reflects the infrared radiation waves to the inside of the house while the outer film reflects the infrared waves to the outside. By comparison, normal windows allow infrared radiation to pass through.
The third principle is to prevent thermal bridges from occurring.
Thermal bridging is the loss of heat through a wall and can be avoided by having two sets of studs staggered across the entire wall in a sort of zig-zag pattern and placing a layer of insulation in the middle of the sets.
This leads to the fourth principle, which is to ensure that the construction of the house is airtight, which means that there are no unnecessary spaces in the walls, floors or ceilings for so that the air can escape.
Bianchi said that to achieve this, air and vapor barriers, water barriers to prevent moisture from entering, and thermal barriers to prevent heat from escaping should each be continuous.
“There can’t be any holes in there that aren’t absolutely deliberate,” he said. “And that’s where the attention to detail ends up giving you a big win.”
He said the house still needs to be able to bring in fresh air.
The fifth and final principle is good air ventilation.
Bianchi said the most energy efficient system is called an energy recovery ventilator which uses fans to draw in air from outside and other materials to convert heat and moisture from that air in cooler, drier air, expelling heat and humidity during the summer.
Cool air in winter is converted into heat by the same system.
Solar panels and excess energy
After the presentation, Bianchi opened the floor to comments and questions from those present.
Some questions were asked about how Bianchi insulated his foundation floor, and more details about the windows he uses – Alpenglass.
Rotary member Barry Kroll noted that Bianchi’s home was in a “very shady” area and wondered how effective the solar panels were.
Bianchi said that although there are “shading issues” during the day, most of the time the panels are in direct sunlight, especially during the summer.
He said he wishes there was a way he could give his neighbors who might not be able to have solar panels installed because their homes are even more shaded his excess solar power at nine to 10 cents per kilowatt hour.
That price, he said, matches what Madison pays Jersey Central Power & Light and other power companies. The borough then charges residents 20 cents per kilowatt hour for their electricity.
Bianchi said he hopes one day to be able to resume home visits as the family did before the COVID-19 pandemic.