©2015 Green Building Advisor. From The Taunton Press, Inc., publisher of Fine Homebuilding Magazine.
Last week I was in Lexington, Kentucky speaking at the Midwest Residential Energy Conference. It was a great regional conference, and the folks there are making things happen. (I even played nice. With all those Kentucky Wildcat fans there, I held back and didn't mention in any of my talks that I'm a Florida Gator.) One of the many highlights for me was getting to visit Richard Levine’s  1970s active solar house. It stands out like no other house I've seen, and I've seen other solar houses.
Your first question upon seeing the photo here might be, “Is that really a house?” Yup. He chose the shape to maximize solar gain while minimizing the area of the building enclosure. It's a cube sliced on the diagonal, which you can see in Part 1 of the video series below. (That part starts at about the 3:30 mark.)
The creek that runs in the ravine near the house is called Raven Run, so the house is called the Raven Run Solar House. Levine designed and built it in 1974-75, one of the earlier solar houses built as a result of the energy crises of the ’70s. Martin Holladay has done a great job covering the history of solar-heated and superinsulated houses in North America. (See Solar Versus Superinsulation: A 30-Year-Old Debate  and The History of Superinsulated Houses in North America .) He contends that superinsulation won because most solar houses overheated on sunny days and froze people out on cold nights.
Holladay may be right overall, but Levine’s home is a great example of a solar home that has performed well. It didn’t overheat because he stored heat in the rock beds below and could vent excess heat out the top when necessary. His main problem was humidity that went a bit too high in summer because passive cooling doesn’t deal with the water vapor in the air.
Here's a quick rundown of a few of the cool features, including what he eventually did about the summer humidity:
Solar collector for space heating. What you see in the photo above is not all windows dumping massive quantities of sunlight into the living space. Some of them are windows, and some are a special type of solar collector that he designed and patented. Each column of collector glazingWhen referring to windows or doors, the transparent or translucent layer that transmits light. High-performance glazing may include multiple layers of glass or plastic, low-e coatings, and low-conductivity gas fill. has corrugated aluminum behind it, and as the air heats up, it rises naturally. The solar gain on those columns of air can provide up to a 100 degree Fahrenheit rise in temperature.
But he's doing more than just using the stack effect . He designed a system that uses a fan to move the hot air from the top of each column down to rock beds in the basement, where the heat gets stored. When it's cloudy, he can draw heat out of the rock beds for two weeks. It's a pretty sophisticated system, and he’s avoided turning the rock beds into a mold factory. One of the photos below shows the original controller for it, which is no longer in use.
Composting toilet. The house has had a Clivus Multrum composting toilet since the beginning. Having built and lived in a house with a composting toilet  myself, I get it. Many people don't, however, especially if it means sitting over a big open hole straight to the tank in the basement. But think of all the water he's saved by never having to flush a toilet in his home for four decades! In the second photo below, you can see the tank in the basement and the access door through which you remove the composted material.
Net zeroProducing as much energy on an annual basis as one consumes on site, usually with renewable energy sources such as photovoltaics or small-scale wind turbines. Calculating net-zero energy can be difficult, particularly in grid-tied renewable energy systems, because of transmission losses in power lines and other considerations. energy. A few years ago, Levine installed photovoltaic(PV) Generation of electricity directly from sunlight. A photovoltaic cell has no moving parts; electrons are energized by sunlight and result in current flow. modules on the studio adjacent to the house. Because of the cold winter this year, he hasn't been net zero in his energy balance between consumption and production over the past year, but he was for the two years before that.
Other updates. Levine recently installed a heat-pump water heaterAn appliance that uses an air-source heat pump to heat domestic hot water. Most heat-pump water heaters include an insulated tank equipped with an electric resistance element to provide backup heat whenever hot water demand exceeds the capacity of the heat pump. Since heat-pump water heaters extract heat from the air, they lower the temperature and humidity of the room in which they are installed. and a decade or so ago had a ground-source heat pumpHome heating and cooling system that relies on the mass of the earth as the heat source and heat sink. Temperatures underground are relatively constant. Using a ground-source heat pump, heat from fluid circulated through an underground loop is transferred to and/or from the home through a heat exchanger. The energy performance of ground-source heat pumps is usually better than that of air-source heat pumps; ground-source heat pumps also perform better over a wider range of above-ground temperatures. put in. The latter was mainly to get cooling with dehumidification. He had relied on natural cooling for a long time but finally decided that the humidity issue warranted a mechanical air conditioning system.
I didn't get to spend a lot of time there, but it's exciting to see that a classic solar-heated house from the 1970s — and one of the earliest ones, at that — has not only survived, but has served its purpose well and evolved gracefully over time.
Levine is a new board member for the Passive House Institute U.S.  (PHIUS), as am I, so I look forward to working with him. He brings a wealth of knowledge, experience, and ideas, which will help immensely as we take this movement further down the road to more sustainable buildings.
CSC Design Studio page on the Raven Run Residence . CSC Design Studio is Levine's architecture firm in Kentucky.
Four-part video series on Levine and his work by kyGREEN.tv :
Allison Bailes  of Decatur, Georgia, is a speaker, writer, energy consultant, RESNET-certified trainer, and the author of the Energy Vanguard Blog . You can follow him on Twitter at @EnergyVanguard .