I saw these today at Home Depot, solar powered attic ventilation fans. This is really smart for a couple of reasons, the first being the fact that heat built up in the typical house attic results in excessive AC usage in the summer as the attic heat keeps the house warm even with insulation. Ventilating attic air also ensures that moisture is evacuated and the attic environment stays generally healthy, so attic fans are just plain old smart building practice.
I have one in our house and it’s set to a thermostat that kicks the fan on when the ambient air temperature reaches 115 degrees in the attic. Basically this is everyday during the summer. These fans are lower power consumption fans but they are running continuously for at 7-10 hours on a typical summer and autumn day.
Here’s why a solar powered attic ventilation fan is a no-brainer, the fan only runs on days that the sun is out and then the fans only run during the day time hours. An attic fan is mounted as either a roof mount or a gable mount, meaning it’s always installed in a location that is sun exposed and if you roof is not sun exposed then you probably don’t need an attic fan to begin with. In short, this is a perfect application for a solar powered appliance.
The price is about $100 more than a line current option but if you are doing this yourself and would have to hire an electrician for a non-solar powered unit then the cost savings alone more than cover the premium for the solar option. This is clean tech that I like, not only does it reduce your energy consumption but it does so in a package that is well tuned to the application and for a price point that is really quite fair.