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With today's cheap power, it is impossible to justify CCAT's solar and wind electrical system on money alone. The electrical system serves as an engineering political statement, as an education tool, and as a center for ecological R&D. On the other hand, CCAT's solar water heating and space heating systems are cost effective, even in today's energy glut.

Solar Water Heating

During sunny periods, water is heated by an active solar thermal system. One of CCAT's first projects was construction of two flat plate collectors. They heat propylene glycol, a non-toxic antifreeze, which is pumped through a heat exchanger in an 80 gallon hot water tank. The pump is powered by an 18 Watt Solec PV panel, and

Above: CCAT's home in Arcata, California. PV power and solar hot water on the roof and a wind turbine in the backyard.

Far Left: the inside of CCAT's greenhouse. Note window from greenhouse into the building's second story.

Left: a cold box in CCAT's kitchen. Here veggies keep fresh and healthy without electric power.

Photos by Mark Newell a differential thermostat turns off the pump when the collectors are colder than the tank, or when the tank is too hot. An Aqua Star natural gas flash heater further heats the water if necessary. In order to reduce consumption of hot water, showers are equipped with low-flow shower heads which draw only 1.7 gallons per minute, compared with regular heads which draw between 3 and 5 gpm.

Urban Passive Solar Retrofit

The house is an excellent example of a passive solar renovation. A large greenhouse spans the entire south side of the house. Besides growing food and nurturing springtime "starts", the greenhouse heats the house. Inside the greenhouse a thick rock wall stores radiant heat trapped during the day. On the main floor of the house, windows open directly into the greenhouse. When it is cold these windows are opened allowing heat to rise into the living space. For summer cooling, the upper part of these same windows open to the outside above the greenhouse. The greenhouse can also vent hot air to the skies if it gets too hot for the plants.

The walls, floors, and ceiling are insulated with fiberglass batting, loose cellulose, and bubblepack Reflectix™. Part of the interior of the library wall of CCAT has a plexiglass covering so you can visually compare insulation types. Cellulose is shredded recycled newspaper, treated with boric acid to make it fire resistant. It is generally less expensive and has a slightly higher R value than fiberglass. It is particularly good for retrofits and attics because it can be blown into existing wall spaces. For this reason, it is also much easier to insulate around conduit and junction boxes. Reflectix is a 5/16 inch thick reflective insulation which is made up of five layers. Two outer layers of aluminized polyethylene reflect radiant heat. Two inner layers of bubblepack resist convective heat flow and an inner layer of polyethylene gives the Reflectix additional strength. The R values for a single sheet of Reflectix range from 8 to 14 depending on orientation. Thanks to a large donation by the manufacturer, CCAT uses Reflectix in many of their solar thermal projects.

Currently, all the windows in the house are single-paned glass. Thermal curtains keep the heat inside at night. The thermal curtains are made out of blankets filled with fiberfill or Reflectix. Magnetic strips in the curtains and on the window frames hold the curtains against the window frame. In the morning, pull a drawstring and the thermal curtains fold up like an accordion above the window.

Hot Boxes and Cold Boxes

The kitchen has several homemade, inexpensive, energy conserving appliances. They have a homemade solar oven and try to use it whenever possible. In addition, there is an insulated hot box in the kitchen that keeps pots of food hot. Food will even continue to cook in one. Rice, for example, that has been cooked for 25 minutes on the stove will finish cooking in 15 minutes once placed in the hot box. Their hot box is simply a drawer that has been very well insulated. The hot box at CCAT was insulated with rigid foam and Reflectix. Rigid foam, however, probably isn't the best choice because it will outgas (give off toxic fumes) when directly exposed to cooking temperatures.

A cold box is an insulated cabinet that has a north facing vent which allows cool outside air to flow into the cupboard. Warm air rises up a flue through the roof to the outside, creating a constant flow of air. Cold boxes were common at the turn of the century — in fact the CCAT house originally had one — but they went out of fashion with the advent of freon. Even though it's efficient, the Sun Frost refrigerator uses a large portion of CCAT's electricity. CCAT students reduce the number of times the refrigerator is opened and closed by storing fruits and vegetables in their homemade cold box.

Natural and non-toxic products are used wherever possible in the kitchen. The walls are painted with Safecoat, a waterbased, non-toxic enamel. The liner of the floor is made out of Naturelich, a linoleum made out of powdered cork, jute, tree resins, and linseed oil. All the cleaning products are biodegradable and safe for grey water system.

Nutrient Cycling

The electrical system and thermal systems try to make appropriate use of locally available energy sources, but CCAT is just as concerned with recycling of organic matter. CCAT's Bill Lydgate and Michael Nelson explain the philosophy behind this:

"CCAT is dedicated to promoting independence and self reliance. This basic challenge has led us to try to complete nutrient cycles at home instead of importing and exporting vast quantities of nutrients in the form of food, fertilizer, and sewage at the expense of energy, money, and pollution. Furthermore, we would feel hypocritical about producing our own power while still using petrochemical based fertilizers to grow our own food.

"In nature, nothing is wasted. Waste is a very human concept created as we break the natural cycles in life, and end up with by-products that are out of place because our lifestyles are out of balance. We have set for ourself the challenge to reincorporate our 'waste' materials back into the cycle instead of throwing them away.

"There are three main nutrient cycling programs at CCAT: human excrement composting and reuse; household greywater treatment and reuse; and kitchen, garden and yard composting."

Composting Toilet

The composting toilet is used by the three residents as well as workers, volunteers, and guests. Even with this high use, the toilet is only emptied once a year. The composting toilet is in the bathroom in the house between two bedrooms. This is an indication that the odor is not a problem.

One of the most important factors of successfully living with a composting toilet is to keep the decomposition aerobic. This will keep the pile healthy and prevent bad odors. To do this, urine is separated from solid waste by a funnel (and poured on the outside compost piles weekly to add nitrogen) and the pile is turned weekly with a shovel. Ninety percent of human manure is water, most of which evaporates. Instead of flushing with 6 gallons of precious water, the toilet is flushed with a coffee can of fresh sawdust. This helps to provide the correct habitat for the organisms that break down the pile by balancing the carbon to nitrogen ratio.

The temperature is recorded weekly in a log, and the health of the pile is monitored. After a year of collecting fresh manure, the full pile is turned into a holding chamber where it is stored for another year. The extra year should exceed the life cycle of any potential pathogen that may have entered the system. The pile is turned weekly while it is in the holding chamber, and the composting temperatures are monitored. To help the composting process, the pile is warmed from below by a coil of 1/2 inch copper tubing containing pumped, solar-heated propylene glycol. An 18 Watt Solec PV panel powers pump whenever the sun shines.

Once a year, the two year old human manure compost is dug into the soil around the fruit trees as a fertilizer. Guess who has the best fruit in the county!

For guests who are squeamish about the composting toilet, the CCAT bathroom also boasts a low flush toilet which uses 2.2 gallons per flush compared to conventional toilets which use up to 7 gallons per flush.

Appropriate Technology

Appropriate technology describes a way of providing for human needs while making the best use of the Earth's finite resources. AT reaps the benefits of both modern scientific advances and effective traditional practices to create solutions that allow people to live comfortably without threatening other peoples or the environment. Appropriate technologies maximize the use of renewable resources through conservation, recycling, and precycling (avoiding packaging). They are designed to be environmentally benign through the understanding of local conditions. The form of an appropriate system is determined by local climate, geology, hydrology, and ecologies as well as by financial, material, and social constraints. This sense of place gives us a deeper understanding of "home".

Appropriate technologies are built for human beings to use, fix, and maintain. As E.F. Schumacher said, it is "technology with a human face", technology which encourages people to rely on themselves for what they need. Small-scale systems such as those in operation at the Buck House help lessen our ties to such

impersonal entities as the supermarket or the power company, and make us realize that we are in charge and have the power to guide our future.

At CCAT we seek to celebrate the resourcefulness and creativity of humanity, to find solutions to human problems, and to live a good life through self-reliance and respect for the natural world.

-Campus Center for Appropriate Technology

_ GREYWATER FROM t* KITCHEN & BATHROOM

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