Solar Attic Fans Can Reduce Your Energy Bill

A Simple Solution To Reduce Your Power Bill

Many Hawaiian homeowners are spending a small fortune to run fans and air-conditioning trying to keep their home cool. The majority of homes, especially older homes, depend on trade winds to keep the their home from becoming unbearably hot.

Typically people who are trying to beat the heat will just install an expensive air conditioning system. What they don’t realize is that they could reduce their power bill and save money simply by improving the ventilation. It stands to reason that if you can keep the heat out naturally, you will need fewer fans and less air conditioning, thus reducing your energy consumption.

How To Keep Your Home Cooler Naturally

Radiant heat from the sun hits your roof on every sunny day. Most roofing materials will absorb much of this heat, especially asphalt or clay tile roofs. Hot air tends to rise but it can get trapped in your attic or vaulted ceiling. If this hot air is not escaping properly, it will migrate downward into your home and it will continue become hotter and hotter inside. That’s why it can often be cooler outside than on the inside of your home.

Consider ventilation like a natural fan that causes the air to move. Ideally, you want a steady, high volume of air flowing through your home.

What you want to establish is known as “Thermal Flow,” where cooler air is coming in and the hot air is going out. This thermal airflow can be established with a combination of intake or soffit ventilation and proper attic ventilation. It’s not just enough to let the hot air out; you have to ensure that cool air is also flowing in.

There are several ventilation systems that create ways for the hot air to escape:

Box vents – These vents are the most common and the least expensive up-front. They are usually made of plastic or metal. You can add extra vents to increase your ventilation however they usually won’t work on vaulted ceilings

Whirly-bird vents – These are a step up from a box vent and function well when a breeze is blowing. The concern is that they are on a ball-bearing system and will eventually wear-out and become noisy.

Ridge Venting – A very good venting solution because it creates a large air-flow over the entire ridge peak. A baffled ridge vent actually creates and area of low pressure on both sides of the ridge vent that will literally pull hot air out of the attic. This “vacuum suction” is known as the Bernoulli Effect, where the wind passing over a structure actually creates a pulling or lifting action. The lifting effect from the difference in air pressures is the same force that allows airplanes to fly and sailboats to sail.

Solar Attic Fans – These are proven to be most effective in removing unwanted heat. The small, built in solar panels cause a fan to literally suck the hot air out. A 30-Watt solar fan will typically be sufficient for every 1200 square feet of attic space. Some solar fans are specially designed for installation in vaulted ceilings. The best fans will have a brushless motor system and a warranty of 20+ years. We see many of the cheaper foreign made units failing within 5-8 years.

Solar Powered Air-Conditioner – If natural ventilation doesn’t solve the over-heating problems, solar-powered air-conditioning can be a great alternative. These cooling units are run completely by sun power. They are stand-alone units and because they don’t tie into your home’s electric system, they don’t require any special permits from HECO.

Both the solar powered attic fans and solar air conditioners are the most powerful way to get the hot air out. Being solar powered devices, they can still qualify for solar tax credits.