October 2, 2021 - January 15, 2022
I’m a retired building systems engineer and I designed and value-engineered my home to be highly energy efficient with minimal added cost. The basement design and passive solar features, along with tight construction, are the primary contributors to ultra-low heating and cooling loads. How low? I estimate the heat pump consumes less than 1,800 kWh/yr. I took a risk with HVAC and installed a single 1-ton heat pump. As predicted, the basement rarely has a heating or cooling call.
The entire energy bill has averaged less than 6,300 kWh/yr (based on 2 years of occupancy). The only fossil fuel is for the outdoor grill.
I advocate passive solar as part of a holistic approach to building design. I collaborated with Debra Rucker Coleman of Sun Plans several years ago, providing mechanical design services for many of her passive solar home clients (circa 2009-2016). Debbie graciously contributed to my home’s design.
The solar array consists of 12 LG panels @ 320 Watts (LG320N1C-G4), 12 Enphase IQ6+ microinverters (IQ6-60-2-US), Enphase IQ Combiner (X-IQ-AM1-240-2) and Unirac GFT ground mount, with 6-ft deep x 24-in diameter concrete footings. The system was installed by my good friend Chad Waits of Net Zero Solar in Tucson. Production has averaged 7,840 kWh/yr thus far, or just over 2,040 kWh/yr per kW. You gotta love southern Arizona!
We would appreciate an RSVP if you plan to visit in person.