Solar Powered Attic Fans - The How and Why Of Installing Them

When it comes to energy usage these days a lot of people are looking for alternative energy sources and as such solar power is very much coming into vogue. At its current level of technological evolution, solar power is a useful means of powering small engines to run simple devices. Fans are one such simple device and you will many instances where using a solar powered fan makes more sense than a fan powered by conventional means.

Many manufacturers now offer solar powered attic fans to ventilate and help keep attics cooler. If there is inadequate ventilation in the attic and poor sealing between the attic and the other rooms in the house, attic fans powered by electric means can potentially draw air from the house into the attic. Not only does this compromise energy efficiency but it can also increase the risk of moisture problems in the attic.

Solar powered fans rely on a small solar panel (typically 10 or 20 watt) to power a DC motor when the sun is shining. The fans are installed with intake vents to provide high-capacity powered ventilation without electric operating costs. Most vents are mounted high on the roof near the ridge and are combined with soffit or gable vents for balanced intake and exhaust air streams. Ventilation is only provided when there is ample sunshine to power the fan motor. The highest fan speed will tend to coincide with the greatest heat from the sun and consequently the greatest need for attic ventilation. By reducing attic temperature, attic fans can help reduce summertime cooling loads while at the same time providing ventilation without the added utility load.

Using solar energy to power air vents in your attic means you eliminate the need for electrical wiring in this part of the house and as a solar ventilator uses no electricity you are also avoiding any ongoing operating costs. You will find that the equipment costs for a solar powered attic fan are higher than those of a conventionally powered fan (around $200 more) but this will usually be offset by the money you save in not having to extend electrical wiring into the attic. In addition to attics you will also find solar powered fans used in greenhouses, outhouses, garages, sheds, out-buildings, and paint rooms.
Retail prices for solar powered attic fans range from about $350 to $600 depending on ventilation capacity, the manufacturer, and optional features such as a thermostat.

In instances of new construction, roofers will usually install powered ventilating units. If these units are solar powered roof vents there will be no need for an electrician to rough and finish wire the units. For retrofit projects, a roofer or do-it-yourselfer will be able to install a solar-powered attic fan using conventional tools and techniques.

Whilst not applicable in every instance where cooling is required, solar powered attic fans are an example of smart thinking utilizing a natural energy source.