Frank Schiavo’s compact, tract-built, three-bedroom ranch-style home in a modest San Jose neighborhood demonstrates that remodeling to create a cutting-edge green home is neither difficult nor expensive. Heated with sunlight and cooled by night air, his home is comfortable, quiet and tasteful, filled with light and local art. With only modest investments in a sun room, extra insulation, new windows, a very small array of rooftop photovoltaic and solar hot water panels, his electricity bill for the coldest, cloudiest months of the year averages a few dollars a month. His gas bill is even more modest.

What’s most impressive about Schiavo’s house isn’t that it’s so comfortable and practical for him to own, it’s that it demonstrates that lofty resource conservation goals can be achieved on a modest remodeling budget.

Passive Solar Energy is Inexpensive

Schiavo’s remodel performs so well, and for so little, because it focuses on conservation, not features. San Jose has plenty of sun, so Schiavo’s house exploits passive solar design. First, Schiavo thoroughly insulated. Next, he added heat-collecting thermal mass (in the form of a small sunroom addition) to store heat energy in the winter and stabilize temperatures. In the summer, he stores the cool of the night air. Interior walls sport an unusual finish detail that, at first brush, appears to have been motivated by modernist aesthetics. Stacks of black, rectangular solids suggestive of consumer electronics protrude from interior walls extending from the floor to chair-rail height. As Schiavo explains, these are actually five gallon metal cans that have been painted black and fitted into steel support racks in key wall sections. The cans are filled with water, which has terrific thermal mass for its weight and volume. Many of these cans are situated in an interior wall that separates the interior from a south-facing sunroom. The water-filled cans store heat in the winter (and the cool of night air in the summer) and release it into the interior of his house.

Passive Solar Heating/Cooling: Operating the House

In the winter and early spring, Schiavo lowers special insulated doors in his sunroom, exposing the water-filled cans. Sun enters the windows of the sunroom and heats the brick-in-sand floor. The warm air in the sunroom then heats the water-filled cans. At night, Schiavo closes the insulated doors, and the water-filled cans radiate heat back into his house. This is an implementation of a passive solar Trombe Wall.

An added benefit of the sunroom space is that it makes an ideal place to hang laundry to dry. Schiavo admits he does use his gas dryer: about a minute or two per load, with no heat, to fluff-up his clothes and remove lint.

Schiavo Himself

A sustainability activist, passive solar design consultant, and retired environmental studies instructor from San Jose State University, Schiavo doesn’t shrink from publicity. A recent article in the San Jose Mercury News (4/5/2008, Is that a lion in the yard? S.J. fence-mural draws second looks) covers the extensive mural in Schiavo’s front and side yards, painted by a friend.

Schiavo first found the public eye in a well-publicized struggle with his local garbage company. Through a combination of disciplined purchasing habits, composting in his yard, and extensive recycling, he has virtually ceased to produce any trash. For years, he continued to pay the local garbage company for a service he wasn’t using. The mayor of San Jose found out and ordered the garbage company to stop billing him. His example led to the City’s composting program, run, incidentally, by a former student.

If you live near San Jose, you can see Schiavo’s house and mural at 1186 Bayard Drive. Look for footprints painted on the sidewalk, position your feet in them, and watch mural, building and landscaping meld into one large piece of art.

Related Articles:

• Life Cycle Costs
• Vancouver Adaptive Reuse
• Super-Insulating Vacuum Glass
• Patrician Place: an Experiment in Energy

What is Heat Exactly?
If we’re going to talk about better ways to heat a home, we’d better have some idea of what heat is. What you experience as heat is just the energization of the molecules in your body. Heat is the energy that gives those molecules kinetic (vibratory) energy.

Obviously, your body produces its own heat through the metabolic process (burning calories); the important thing is that your environment neither inundates you with excess energy (when it’s too warm), or draws too much energy away from you (when it’s too cold). This begs the question, how does your environment give or take energy from you?

Physicists and engineers call the process heat transfer. There are three different mechanisms: radiation, conduction, and convection. Radiation is what you feel when you stand in front of a fireplace or in sunlight. Electromagnetic waves, primarily in the infrared portion of the light spectrum, strike you and transfer their energy. Conduction is how a coffee cup warms your hand: the kinetic (vibratory) energy of the coffee mug creates a resonance with your molecules, transferring energy. Convection heats by moving a warm fluid (typically air) across a cooler surface (you). In each case, the warmer object loses energy to the cooler one.

Another way of looking at heat transfer explains cooling in terms of heating: if you decide something is too warm, you cool it by finding something colder and facilitating heat transfer between the two. Strangely enough, for substances like gases (say, air), you can apply mechanical energy to drive this flow of energy. When you compress a gas, you raise its temperature; now the heat will tend to go some place cooler (indoors, if you’re trying to heat, or outdoors, if you’re trying to cool). When you remove the pressure, the gas is now cooler than its surroundings. Heat pumps, including refrigerators and air conditioners, work this way, more or less.

Unfortunately, the occupants of a house can’t depend on contact with warm, solid surfaces as a primary source of heat (despite what you might hear from people who deal in heated counter tops and toilet seats). At best, conductive heating is a side benefit (or a luxury feature). Thus, home heating is primarily about radiation and convection, known as radiant heating and forced air heating, respectively.

The next article in this series explains the drawbacks of using forced air heating, cooling and ventilation systems (HVAC).

Previous articles in this series:
Heating Your Home: Radiant Heat, Wood Heat.

Related articles:
Super-Insulating Vacuum Glass

According to the U.S. Department of Energy, heating and cooling amounts to 46% of all energy consumed by our homes. Water heating uses another 14%. In coastal California, where extreme heat is rare and winters are mild, a properly sited, well designed passive solar home can generate its own heat and hot water, and do without air conditioning.

Historically, few homes are so well sited or built. Since our area has more heating days than cooling days, most homeowners need a heating system. What few know is that many indoor air quality problems can be by-products of forced air heating, ventilation and air-conditioning (HVAC) systems installed in their homes.

Too often, homeowners are unaware that they have better options. Radiant heat delivery is more efficient than forced air and has the potential to solve a number of indoor air quality (IAQ) problems. Fewer still know that wood-based radiant heat, besides avoiding these IAQ issues, has even more benefits. Significantly:

• wood heat is usually less expensive than fossil fuel
• heat produced from wood is carbon-neutral
• with the right equipment, wood will burn cleanly enough to meet stringent air quality standards

Some municipalities also are unaware that wood can be burned cleanly, and prohibit wood burning appliances in new homes. If we don’t take the time to educate others about the benefits of wood heat, one of the next best alternatives to solar heating is in danger of being banned everywhere.

The next article in this series explains what heat is and how it’s used to warm a home.

Photo credit: Temp-Cast Enviroheat LTD