Tag: Passive House

John Avenson of Westminster Is a Committed Teacher of Energy Efficiency

The sponsors of the annual Metro Denver Green Homes Tour, held on the first Saturday each October, are preparing to “go virtual” in case an  in-person tour is not allowed.

John Avenson’s house at 9988 Hoyt Place, Westminster

That will be accomplished by creating online video tours of the most notable “green” homes featured over the past 20 years. Since I’m on the steering committee for the tour and have the equipment and experience from creating video tours of homes for sale, I volunteered to create those video tours, starting with John Avenson’s home at 9988 Hoyt Place in Westminster.

By clicking here, you can view the 41-minute video tour, led by John, which I created last Friday. It is highly educational.

John Avenson

Many people, myself included, have created homes which can be considered a “model” of sustainability, solar power, and energy efficiency, but John is surely the only homeowner who has turned his home into a classroom for teaching it. He even posted pictures and diagrams throughout the house with instructional content about this or that feature, as you will see on that video.

He also hosts monthly Passive House meetings in his home theater which are also streamed online. They can be found at www.meetup.com/Passive-House-Meetup-S-W-Region/

John’s house was originally built by the Solar Energy Research Institute (SERI, now the National Renewable Energy Laboratory or NREL) in 1981 using then-state of the art technology, but John has diligently, and at great personal expense, kept retrofitting his home with newer technology, which he is happy to explain to visitors and which he explains on the 41-minute video.

CERV monitor screenshot

For example, because of increased insulation and Alpen quadruple-paned windows, he was able to get rid of SERI’s supplemental natural gas furnace, installing a conditioning energy recovery ventilator (CERV) which is powered electrically. His grid-tied solar PV system provides all his home’s energy needs and has reduced his Xcel Energy bill to under $10 per month — the cost of being connected to the electrical grid.

Some of the technological innovations featured in my video with John were new to me. For example, the Alpen windows across from his kitchen have horizontal micro-etching which redirects the sun’s rays 90° upward to his ceiling instead of straight through the glass, reducing the need for lighting.

John provided his email address in the video, saying that his “learning center” is open 24/7 and that he welcomes all inquiries and visitors.

Passive House Technology Underlies Going ‘Net Zero Energy’

“Passive House” is a concept born in Germany as “PassivHaus” but growing in popularity here in America. Although its primary focus is on reducing the heating and cooling needs of a home through proper north/south orientation, the placement of windows, and roof overhangs, it also includes design elements that make a home better for its inhabitants. It has many other positive impacts as well, including healthier and quieter spaces, greater durability, and greater comfort for inhabitants.”

Prior to the oil embargo of 1973, home builders did not concern themselves much with making homes energy efficient, but that all changed as we quickly realized how dependent we were on foreign countries for fossil fuels to heat our homes and fuel our cars. Homes built before then were poorly insulated, drafty and less healthy.  (For example, lead-based paint wasn’t banned until 1978.)

The passive house concept took off in America as a result of that wake-up call. The “Lo-Cal” house created in 1976 consumed 60% less energy than the standard house at the time, and the concept continues to mature.

If you participated in any of the “green home” tours that Golden Real Estate co-sponsors each fall, you’ve learned about various passive home strategies in addition to “active” strategies such as solar power, heat pumps, geothermal heating, and energy recovery ventilators.

When “active” systems are introduced to a home with passive house design, they work more easily to create the ultimate goal of a “net zero energy” home — one which generates all the energy needed to heat, cool and power the home and, perhaps, charge the owner’s electric vehicles.  Without passive house design features, you can still achieve net zero energy, but it may require substantially more solar panels to compensate for such factors as inferior orientation, fenestration (windows) and insulation.

You can learn all about passive home technology, including trainings and public events, online at www.phius.org. Also, search “Passive House SW” at www.meetup.org for local events.

An excellent example of new construction which combines passive house design with smart active systems in the Geos Community in Arvada, which you can learn about online at www.DiscoverGeos.com. The homes in Geos are all oriented to maximize solar gain in the winter, but also designed for sun shading in the summer. Some have a geothermal heating, while others have air source heat pumps and conditioning energy recovery ventilators (CERVs). The CERVs installed in the Geos homes not only provide heat when needed but also track the level of CO2 and volatile organic compounds (VOCs) in the air and adjust their function to reduce those levels, thereby improving indoor air quality.

None of the Geos homes uses natural gas, just solar-generated electricity.