Using an old technology that's gaining new attention, Alex Avery is partially heating her home with help from the sun.

She's hoping the solar hot air circulating system she had installed in October will reduce her electric bill considerably.

A duct system equipped with a small fan draws air from inside Avery's home near Santa Fe and funnels it up to a solar collector on her roof. The air flows through the collector, passing between a black-painted aluminum sheet and a special thermal glass, and is warmed by the sun. Then the air is blown by the system back into the house. Dampers control the air flow and a thermostat controls the temperature.

So far, Avery's been pleased. "It can be 16 degrees outside, and inside it will by a steady 68 degrees [with no additional heat source]," she said.

It only works during the day, and is best, of course, when the sun is shining. At night and on New Mexico's rare cloudy days, Avery uses a wood stove and electric heaters to boost the temperature.

Electric heaters and wood were her only heat source until she had the new system installed. An old radiant floor system in the house had failed and would have cost more than $30,000 to replace. The cost, plus Avery's desire to reduce her use of fossil fuels, sent her looking for alternatives.

She read a lot about other solar power systems. She settled on the air-circulating one as the best option for the least money.

Avery, who owns a boutique in Albuquerque, tracked down Triple A Solar Service, which makes the solar air circulating panels. Through them she found Belen installer Jeremy Martinez, a licensed electrician who owns Sol Energy. Martinez already had a decade of work as an electrician under his belt when he started learning about solar. "It amazed me," he said. "The more I put my hands on it, the more I went ' wow.' "

Martinez said versions of the solar circulating air system were installed in many New Mexico homes during the 1970s and '80s, when the state was a leader in solar development. But, "As soon as the tax credit went away, so did the systems," Martinez said.

Avery's system for her 2,000-square-foot home ran about $8,000 for materials and installation. Martinez said typically he can install one of the systems for $3,500 to $5,000, depending on the size of the house. The downside of the system is it doesn't qualify for the solar tax credits and incentives currently available for solar photovoltaic systems. This system is, however, exempt from sales taxes.

Avery's electricity bill in November was $75. Martinez said most people using propane for heat can reduce costs by one-third to two-thirds.

Martinez can install the panel on the ground and run the ducting underneath trailers. He can also mount the panels directly onto a wall. The system can easily work in workshops, kennels and barns as well as homes and offices, he said. The systems require little maintenance, he added, and the panels come with a five-year warranty.

"I've seen some of these where I went to replace a blower and the system has been in there 30 years with no trouble," he said.

In the summer, people simply turn off the thermostat that controls the solar hot air circulating system. Some cover the solar panel with a protective cloth, much like the ones used on air conditioners in the winter.

Contact Staci Matlock at 986-3055 or smatlock@sfnewmexican.com.