Solar house earning returns
On a quiet dirt road cul-de-sac surrounded by panoramic views of sage dappled prairie, a traditional adobe dwelling sits drinking in the New Mexico sun like photosynthesizing plant life.
The house boasts all the charm of old fashioned Pueblo style, but has the modern advantages of high tech, state-of-the-art engineering and solar power. Passive solar is used in the design and photovoltaic panels are used to collect energy from the sun.
The recently built Belen house provides New York couple Pam and Sal Primeggia not only respite from the bustle of big city life, but a monthly check from PNM.
The design of the house was masterminded by Los Lunas residents Alex and Laura Sanchez.
They have been involved in passive solar design for decades. Alex teaches green building and computer-aided drafting at the University of New Mexico-Valencia Campus, and Laura ran a design and drafting business specializing in passive solar designs.
They have co-authored a book about affordable solar adobe houses, “Adobe Houses for Today — Flexible Plans for Your Adobe Home,” published by Sunstone Press.
The couple was approached by UNM-VC biology professor Claudia Barreta, who asked them if they would design a house for her sister and brother-in-law.
Barreta moved to Belen six years ago, and about two years later, her sister, Pam, and brother-in-law, Sal, bought 2.6 acres adjacent to her property as an investment.
“She (Claudia) bought the property across the street and behind, and said, ‘Wouldn’t you like to invest in the property next door?’ And we did,” said Pam.
As Pam and Sal approached retirement, they decided to build a house on the property.
The sisters met with Alex and Laura at a local restaurant to discuss the house to be built and offer a wish list of features they hoped to implement, Alex said.
“We left excited about the idea of designing a comfortable passive solar ‘zero energy’ house for Pam and Sal,” he said.
Out of the collaborative effort, a 2,200 square foot, grid-positive solar house was built utilizing local contractors for the project.
Los Lunas contractor Hansen and Prezzano Builders teamed up with Andrew Otero, and built the house.
The seven kilowatt solar system was installed by Jeremy Martinez, owner of Sol Energy in Belen, with 30 photovoltaic panels mounted on the roofs of both the garage and a portion of the house.
The walls are made from concrete blocks filled with foam, called “green blocks,” for insulation, and a new, state-of-the-art central heat and refrigerated air system that was installed by Johnny Gardner, owner of Gardner Plumbing & Heating Service in Belen.
“It’s new in the sense that the efficiencies are pretty amazing,” Alex said.
Gardner had never installed one of these before. The system uses the same ducts, so the Primeggias aren’t paying for two separate systems.
The air conditioner is so quiet, Pam said she doesn’t even know when it comes on.
She has the thermostat set to 77 degrees and said she hasn’t had to go any lower as long as they keep the windows and doors closed.
But they open the bedroom windows on most nights to enjoy the nice breezes that come in, Pam said.
All the floors are ceramic tile on concrete to hold the heat or cool and maintain the desired temperature. All the windows are double-paned, even on the doors.
One of the neat features of the windows, besides air-tight insulation, are the mini-blinds between the panes to reduce the need for cleaning.
The ceiling has fiberglass insulation. Laura thinks sufficient ceiling insulation is more important than wall insulation.
All of the appliances are Energy Star, and the motion sensor security system is solar run.
“We didn’t want a propane tank in the backyard, so everything is electric,” Pam said.
Electric houses have a reputation for high electric utility bills, but the normally high electric load is reduced by using passive solar for heating, natural night ventilation for cooling, the super efficient heating and cooling system and the hybrid water heater, said Alex.
“It’s a regular water heater, like an electric water heater with the element in it to heat the water,” he said. “Then on top of it is this little bonnet — the heat pump.”
The heat pump draws heat out of the air and transfers it — the same process as before with the coil unit — and draws it into the water at a higher efficiency than the element would. It claims to save 62 percent of your energy use versus a regular water heater, Alex said.
The house is shaded on the east and west ends by spacious screened-in porches along with wooden awnings above windows, so the house doesn’t heat up, said Laura.
The awnings extend just far enough to curb summer sun without eliminating the winter sun. Laura figured in the seasonal angles of the sun when she designed them.
“You want to get more sunlight into the living areas, the common areas that are open — the living room, dining room kitchen — rather than an overheated bedroom,” Laura said. “Over-heating is almost a problem more than getting enough heat.”
The length of the house was built on the north-south axis with lots of windows on the south side to take advantage of the longest sun exposure, an ancient practice.
Pueblo Indians have made use of southern exposures for millennia, such as the rock dwellings that open to the south, like Chaco Canyon and Casa Bonita, Laura said.
“The garage is on the north side of the house, because it serves as an insulating barrier against the cold,” she said.
Currently, the Primeggia’s are making more energy than they use, and receive about $80 a month from PNM.
“We don’t have a whole year’s worth of bills yet,” Alex said. “So, it’s kind of hard to tell what it’ll do in the winter.”
By day, the house’s photovoltaic system provides electricity, but at night, the house operates using energy from PNM’s grid.
UNM-VC students enrolled in Alex’s sustainable building classes have the opportunity for hands-on learning.
“This past spring semester, the first energy auditing class performed an energy survey of the house using a blower door and infrared cameras,” Alex said. “This fall, the green building class will repeat the energy audit and compare results. Because of the extent and variety of energy saving features, this house is a prime teaching example for students.”
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