Solar Attic Fans
Ventilate Your Attic with Energy From the Sun
Any homeowner knows that a properly ventilated attic is critical to the structural integrity of your roof, not to mention the comfort of your home. Without sufficient airflow, heat can get trapped in the attic, increasing the load on your A/C unit in the summer and causing dangerous ice dams in the winter. In addition, trapped moisture can cause wood to rot and allow mold to grow, threatening the safety and health of your family. Thankfully, keeping your attic properly ventilated can help you avoid these issues, and a solar attic fan provides an exceptionally effective, eco-friendly way to do so.
How Do Solar Attic Fans Work?
Whether from the hot summer sun, rising interior warmth, rain, or condensation, warm air and moisture in the attic can cause significant damage to your home. Soffits and gable vents provide entry and exit points for air to flow through an attic, but they rely on natural convection, and this is oftentimes not enough to ensure sufficient airflow. A power attic ventilator (PAV) pulls air up through soffits or vents, circulates it to pick up heat and moisture, and then pushes it back out. This process keeps the temperature in the attic lower and allows moisture to evaporate and escape quickly.
Benefits of a Solar Attic Ventilator
As with a traditional PAV, a solar ventilator is mounted to the roof of a structure and uses a fan to circulate air through the attic space. However, a solar unit is not bound to an outlet and instead uses a small solar panel to capture energy from the sun’s rays and power the fan. Not only does this save energy, but it allows for more flexibility when placing the fan and means the system will work even during a power outage. Another major benefit to solar is its efficiency. A traditionally powered attic ventilation system uses a thermometer to gauge when the system should turn on. However, by the time it’s activated, the attic is often already extremely warm, causing the fan to run longer to play catch up. A solar fan turns on at dawn, so it starts working before heat builds up, plus it dries out condensation formed by cool night air on wood and insulation.
|Stay Cooler in the Summer
Vents your Attic:
Removes damaging heat and moisture by keeping your attic up to 15 degrees cooler in the summer.
Ventilates up to 1800 sq. feet with no electricity expense. Lightens the load on your air conditioner.
High-quality solar cells begin working at dawn to prevent heat build-up and runs until dusk without harmonic noise.
|Protect your home in the winter
Maintains attic temperature:
Helps maintain consistent attic temperature to help prevent ice dams.
Removes moisture build up that can affect insulation performance and lead to mold and mildew problems.
Hurricane rated to 140 mph wind and driving rain. Will not leak from melting snow.
Our Solar Attic Fan: Quiet, Heavy-Duty, Reliable
Renewable Energy Corporation is proud to offer Solar Dynamics SDF-20SF model solar attic ventilator.
Some details of this model include:
- High-efficiency 20 watt photovoltaic unit
- Offers reliable ventilation for up to 1800 sq. feet, moving 1275 CFM of air
- Withstands 140 mph winds and resistant to hail and other extreme conditions
- Flush-mounted design offers unbeatable durability and reliability with respect to both performance and looks
- Operates from dusk until dawn, even in hazy conditions
- 5-year warranty on labor and parts, stainless steel brackets, UV stabilized plastic, and a heavy-duty bird and rodent screen
- Solar Dynamics has been producing high quality solar attic fans for the last 20 years right here in the USA
Solar Dynamics SDF-20SF
Slim profile, 7-1/2” high, square design blends in well with angular pattern of shingles. Surface mount models designed for most standard sloped roofs with regular or dimensional shingles.
Heavy gauge stainless steel bird and insect screen provides maximum protection from insects and animals without impeding air flow.
Specially designed one-piece, 12” aluminum 5-blade fan is pitched for maximum airflow and operates whisper-quiet with no harmonic noise.
Frequently Asked Questions: Solar Attic Fans
Click to reveal the answer:
A: During the summer, as the sun radiates heat onto your roof, your roof’s shingles or tile become very hot, well above 150 degrees F. This heat is transferred through the roof and in turn heats the air inside the attic. Ridge vents or soffit ventilation is sometimes referred to as convection ventilation, the theory being simply “hot air rises” and will vent on its own. Unfortunately this theory is somewhat flawed because heat also expands and radiates. The roof holds the heat, the attic holds the heat, and everything in your attic holds the heat. As your roof begins to broil, the air in your attic begins to expand, in every direction not just up. There is no question the vents at the ridge of your home will exhaust air, but only as it is warmed to the point of expansion. In short, the convection-ventilation process actually requires heat retention to begin in order to maintain this inadequate ventilation process. Your roof will never be cooler than the heat load point required for convection and by the time that happens, your house is already cooking, causing your air conditioner to have to work harder.
A: If the hot air stays inside your attic, the heat from this air will eventually enter your home forcing your air conditioner to work harder to eliminate the heat. By removing the hot air from your attic, the process of heat transfer into the home is minimized.
A: thermal switch is designed to shut off the fan once the attic temperature drops to roughly 50 – 65 degrees. F. The benefits are regional and mainly for winter application. Some parts of the country may experience very dry cold winters, in this case ventilation is not necessary since moisture and ice dams are not as great a concern.
A: At first light our SPAV begins to exchange the air in the attic – before the heat of the day. It does so silently – and without harmonic noise that AC motors generate. By starting early, heat-gain is all but eliminated. Moist air that may have entered the home during the night is drawn out before it has an opportunity to heat up, stopping the compounding effects of humidity, and dramatically reducing the potential for mold and mildew.
A: Although it’s true, in winter your attic doesn’t see the oppressive heat of the summer sun, the colder season offers its own set of issues that proper attic ventilation can help to eliminate. Just as the sun’s effects are stronger depending on your position on the globe, the same holds true for the winter’s cold. The very dry, cold climates, as a rule, don’t experience some of the negative effects of winter humidity. However many areas still continue to experience moisture build up in the attic that can lead to the dampening of insulation, mold and mildew. When insulation is dampened, it becomes inefficient and forces your furnace to work harder. Add a little snow to equation and the constant changing temperatures is a leading cause of ice dams.
A: An ice dam is a ridge of ice that forms at the edge of a roof and prevents melting snow (water) from draining off the roof. The water that backs up behind the dam can leak into a home and cause damage to walls, ceilings, insulation, and other areas. Ice dams can be prevented by controlling the heat loss from the home. A solar attic ventilator helps in two ways, first by controlling the temperature in the attic, eliminating the cold and hot spots that cause the snow to melt and refreeze and second by helping to eliminate damaging moisture that can dampen the insulation rendering it useless and allowing the heat to escape.
A: The Solar PAV is very easy to install – easier than a Standard PAV because there are no electrical wires to connect. A homeowner could install one in less than an hour and a professional in less than 30 minutes. Installation on a tiled or cedar shake roof, flat roof, or severely steep roof requires a curb mount installation and a bit longer installation time. Solar Dynamics has the product to fit this application as well and can provide detailed instructions on how to build a curb out of simple 2 x 4′s. (A curb is nothing more than a box to form a slightly raised platform)
A: The Solar Dynamics SPAV can easily replace existing PAV’s in a matter of minutes. In MOST, if not ALL cases, the roof opening will be acceptable to the SPAV. It’s as simple as removing the nails from the surrounding shingles, removing the old PAV, sliding in the new, caulking, and nailing the shingles. The electrical connection must be capped off inside the attic. That’s all there is to it.
A: The Solar Dynamics SPAVs are paint compatible. The roof surface mount is offered in three of the most popular colors; black, brown and weather wood (dark grey). However, if someone has a green roof and they want the SPAV to match, painting is not an issue. Specifications for the type of paint are provided in the installation instructions.
A: Solar powered attic fans can be roughly classified into two major performance categories: 10 watt and 20 watt. The 10 watt SPAVs are typically less expensive and ventilate less than 1200 sq. feet. Since the majority of residential attics are larger than 1200 sq. feet, it is usually necessary to install multiple units to meet ventilation requirements of a home. This means more roof penetrations, and fan installation and can raise the cost significantly. The higher powered, 20 watt SPAVs are usually sold by professionals and are designed to move quite a bit more air. While more expensive than the 10 watt versions these fans have the capacity to adequately ventilate an attic space up to 1600 sq. feet or more. They are constructed of quality materials and designed to provide years of service.
A: The Solar PAV is designed to be effective no matter the angle of the sun, but studies have shown that positioning on the globe can play a role in the effectiveness of the photovoltaic cells for all Solar products at capturing the maximum percentage of sun’s rays. Those regions with the greater amount of direct rays, on average, will perform at peak efficiency a greater percentage of the time. When the sun moves farther into the southern hemisphere during the winter months, the entire US can expect to experience a drop in the performance of all solar products but these are also the months when heat build-up in the attic is not as great a threat.
A: Solar Dynamics’ Solar-Powered Attic Ventilators are the best at removing heat and moisture from your attic because every component has been aesthetically designed and engineered for superior performance. From the solar panel to the low-profile housing, we have built consistency and quality into our manufacturing ensuring our product delivers the performance you expect while looking great on your roof. You take pride in your home so why would you want to upset the look of the roofline with an unsightly panel jutting up a foot or more? The Solar Dynamics difference begins on the outside, with a low-profile square design that matches more closely with the geometric pattern of shingles. Unlike many SPAVs that require the solar panel be raised and angled toward the sun to be effective, the Solar Dynamics SPAV has a low 7-1/2″ profile.
Highly Effective Solar Panel: Unlike most solar attic fans, you can expect consistent performance from our photovoltaic cells because we are utilizing top-of-the line, high quality cells as opposed to off-the-shelf, inferior panels. These panels cost a bit more, but the result is worth it – the fan does what it is designed to do – remove the heat and humidity from the attic space. Without getting too technical, our photovoltaic cells have a heightened light sensitivity which means they will perform better in less light. To prevent heat build-up and remove nighttime moisture, it is critical that the ventilator begin as soon as the sun comes up. Because our panels are so light sensitive, they will begin at dawn and keep on working until dusk. And our panels are individually tested at the factory to ensure they are outputting a full 20 watts. If they don’t meet this standard, they are rejected. You can be assured that the product you take out of the box will perform as expected once it’s on the roof.
Heavy Duty Motor: Our top-of-the-line motor – engineered for this application – will provide years of maintenance-free performance. Its Whisper-quiet, direct current motor ventilates average size attics of 1600 sq. ft. Our Variable voltage motor automatically adjusts the fan speed based on the amount of available sun light which means it can run in all light levels not just when the sun’s rays are strongest. Sealed ball-bearings provide increased protection against motor wear while our zinc plated, steel motor housing provides protection against corrosion. Finally our dynamically balanced motor reduces noise and damaging vibration. While other SPAVs use less costly brushless motors, our durable motor features replaceable brushes to further extend the already long life.
ABS Dome: Many fans use a metal housing that conducts temperature, dents, rusts and corrodes. The Solar Dynamics SPAV was designed to resist these attacking elements, made from molded, UV-enhanced, ABS plastic. The color is consistent throughout, and will resist dents, scratches and marring.
A: The effectiveness of the solar panel at capturing the sun’s energy and converting it to power is at the heart of how a Solar Dynamics SPAV performs. It would seem logical that angling the panel to directly face the sun should enhance the performance. However ANGLING IS ONLY REQUIRED IF THE SOLAR PANEL IS INEFFICIENT AT COLLECTING THE SUN’S RAYS.. Because we use highly sensitive panels, we are able to design a streamlined product without unsightly pieces jutting out from the roof. Don’t be fooled by claims that the angled panel is more effective. The Solar Dynamics SPAV panel does not have to be raised because it is engineered to be efficient while flat.
A: Standard PAV’s offer many of the same benefits that a Solar PAV does, venting out the hot air built up within the attic. But actually, that’s where the similarity ends. Beyond the obvious cost savings would it surprise you to learn that a Solar PAV is actually BETTER than a PAV at removing this heat? When choosing between a PAV and an SPAV, many think that opting for a Solar PAV is either an attempt to lower their electricity costs or a gesture at helping the environment. Both are valid reasons, but neither touches on the real reason one should opt for a SPAV – performance. The Solar Dynamics SPAV panels are highly light sensitive because of our high-grade photovoltaic cells and can begin working at dawn to eliminate the moisture that has built up from the cool overnight air, and then, prevents heat build up. A PAV has to reach a high temperature before the thermostat kicks in and tells it to start working. By this time the moisture has already worked its way into the insulation and the walls. Because it has to play “catch-up” the PAV is already starting out at a disadvantage and must run all day. Driven off AC power, a PAV can be noisy emitting “harmonic noise”, and although it is possible to override the thermostat and let it run, the motor is not designed to handle this constant demand and will be subject to failure much sooner.