Can A 13 SEER AC Unit Make Sense For Energy Efficiency?

I’m visiting this week with some former Austin neighbors who now live at 8,000 feet elevation in the mountains above the town of Ruidoso, NM. They just had a new house built and, being curious about their new HVAC system, I took at look at the outside AC unit. When I looked at the energy efficiency rating and saw only 13 SEER, my first thought was this: their builder ripped them off! Then, I remembered my hosts saying that, even thought it’s mid-August, they had only run their AC system for a few hours on two afternoons all summer. Luckily, I had not embarrassed myself by thinking out loud.

My next stops were under the house and in the attic. There I saw a gas furnace rated at 97% efficiency (the efficiency range of new furnaces is about 80-98%) and super thick insulation. Thinking it though, and knowing about the “whole house” approach to energy use and conservation, the reasons for their choices became clear. Due to the high elevation, colder winters, and minimal need for air conditioning, they spent proportionally more on passive solar design and windows, high-efficiency heating, and extra insulation to retain more heat.

Coming from Austin, with its long, oven-hot, subtropical summers, at first it seems a bit ironic that relatively low efficiency AC equipment of any kind can make sense.  However, when considering what my friends did with the extra money that higher efficiency equipment would have cost (or other energy use that was avoided in not generating the income to buy overkill efficiency) the interconnections do get interesting.  The focus of this post is on a new system. For a list of way you can lower utility bills and energy usage on your existing equipment, visit this page.

Leave a Reply