Buried fresh air intake
A local TV station ran a story about a recently built energy efficient house. It was in a rural area and not on a city lot. They were short on details of what made the home energy efficient. They said wall and floor were concrete so it sounds like they have an ICF house. There is a solar panel array. Last summer the ac cost $3 a month. No mention if that was total energy use.
The homeowner claimed “it does cost anymore to build” and she didnt know why more people didnt build ee homes.
They spent the most time talking about a fresh air intake. A pvc pipe was buried 10 feet deep and runs to the house. They didnt say how long the run was but it went quite a distance. This allowed a fresh air intake of “60 degree” air year around.
I would like to hear your views on such a setup. Personally I would worry about the potential for mold and bacteria growth inside the pipe fowling the incoming air.
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Robert,
Was the homeowner named Katrin Klingenberg? If so, here is more information on her house (it includes a buried earth tube): The First U.S. Passive House Shows That Energy Efficiency Can Be Affordable.
You're right that buried earth tubes sometimes have moisture and mold problems. Here's an article about one disaster: Belgian Passivhaus is Rendered Uninhabitable by Bad Indoor Air.
No the home was near Omaha, NE. They showed the pipe sticking up from the ground but you didnt see the home. What did it cost to dig a 10 foot deep trench and how would that compare to the cost of a HRV/ERV.
I just thought it was poorly reported. I am not an expert in the cost arena but an ICF home with concrete floors with radiant heat does not cost the same to build. The cost of 18 solar panels would be an additional cost. They were short on details and lead with fluff. As someone interested in energy efficiency I didnt think it did much to inform the consumers.
Use of earth tempering the ventilation air with underground pipes is rife with hazards, particularly in climates with high summertime dew points well above the subsoil temps, which can lead to disastrous levels of mold in the ventilation air. I wouldn't do it in Omaha, but I might in Las Vegas or Fresno. Either way the effect on energy use reduction is usually quite modest, and the economics won't always make sense.
Don't expect local TV reporters to understand the difference between kilowatt-hours and kilowatts, let alone energy use modeling of different approaches, eh? (The job has more to do with reading the teleprompter without stumbling and looking good, not understanding and delivering the financial & economic details of energy efficient buildings.)