Solar Attic Fans Pros and Cons
Solar attic fans are mechanical fans powered by solar panels that could be an ideal option for homes that receive surplus amounts of sunlight. These fans increase the aesthetic value of the home while helping you live a sustainable lifestyle. Though the cost of solar attic fans is high, government incentives make the purchase possible.
However, it may take 10-15 years to recover the initial investment. Also, it may seem easy to install the roof fans, but if not done correctly, may create leaky roofs. There is a need to hire a professional and the cost of installation may increase the net cost of a solar roof fan. Other than this, just one fan may not be sufficient to take care of a large-sized attic, thus adding up the cost.
This blog drills down 20 such pros and cons of installing a solar roof fan in your home.
Solar Attic Fans – Top 20 Pros & Cons
10 Pros of A Solar Roof Fan
1) Pay once, save later
Investing in a solar roof fan can be a cost-effective decision in the long run. These fans have a long lifespan and operate without contributing to your electricity bill as they are powered by solar energy. On the other hand, using an electric attic fan can increase your energy consumption during hot summers, leading to higher electricity bills. In contrast, a solar roof fan operates for free, making it a more eco-friendly and economical option.
2) Maintains attic temperature
During the scalding summers, the temperature of the attic may rise to 130⁰. This creates a dire need to lower the attic temperature to maintain the lower temperature of the house. A solar-powered fan uses this sunlight to push out the warm air in the attic, thereby reducing the workload of the air conditioner. This also helps save money during the warmer seasons. These fans also help to pull the air into the attic during the cooler seasons, thereby warming up your home in an efficient manner.
3) Noiseless
Unlike solar roof fans, electrical vents need more power to remove hot air from the attic and cool it down. The electrical vents produce a humming sound of 50-60db which may end up irking someone. The brushless motors of solar attic fans enable them to function silently while rotating at 1600 RPM.
4) No electrician required
To install a traditional electrical fan to the grid, an electrician is required to do so which adds up to several hundred dollars in the cost of installation, whereas it is easy to install a solar fan by yourself. Besides this, the electric fans create a negative pressure zone, during which they pull the air from the air conditioning system of the home. Electric fans are known to have burn-out and end up in fire hazards. On the other hand, solar-powered fans ensure safe use.
5) No risk of carbon monoxide
The electricity-powered attic fans may create negative pressure zones that pull the carbon monoxide from the combustion appliances of the home into the attic. Exposure to carbon monoxide gas can lead to harmful effects on health. Solar attic fans do not function on electricity; hence this risk is avoided.
6) Save your roof
During the winter season, the heat rises to the attic. This solar roof fan helps to prevent moisture-related problems like mold and wood rot. If there is poor ventilation and insulation in the attic, it may result in “ice damming” because of the warm air leaks from the interior. This warm leaked attic air will melt the snow on the roof and when the snow freezes again, it will form ice on the edge of the roof. When more amount of snow melts, the ice at the edge of the roof holds it like a dam. This “ice damming” can damage the sheathing and the walls of the home. The use of a solar fan can help prevent this trouble by facilitating ventilation and preventing the accumulation of warm air in the attic.
7) Low Maintenance
A solar fan runs on an inductive motor that faces minimal wear and tear making it low maintenance. A solar fan also has a longer lifespan. As some of the electric fans come with thermostats that stop them at regular intervals, the recurrent on-and-off cycles may create problems.
8) Green Energy
Solar fans reduce dependence on exhaustible fossil fuels by harnessing abundant natural energy. These fans do not produce any harmful greenhouse gases like methane, carbon dioxide, or nitrous oxide, there is a little less worry about the carbon footprint of the home. The worries about the adverse effects of greenhouse gas emissions on health are also reduced. The solar fans help you live a sustainable life.
9) Aesthetically impressive
The installation of a solar fan can make a style statement of being eco-enthusiast. It can motivate others to go green and save energy as well. To install a solar fan, there is no requirement for roofing cement, caulk, or any other product to prevent leaking. All you need to do is cut a hole or more depending on the number of fans you get. Then, fix the fans in the roof to get an aesthetically impressive seamless look.
10) Government Incentives
The pressure on the fossil fuel industry is boosting solar energy markets and is well supported by governments across the globe as well. Despite the high cost of solar fans, government incentives and policies make it possible to purchase one. Before buying a solar fan, one can confirm the availability of such incentives to make sustainable living inexpensive.
10 Cons of A Solar Roof Fan
1) Initial cost
When compared to the alternative types of attic fans, like electric fans, the cost of purchasing a solar fan is way too high. A solar fan may cost up to $300-$600, and the cost of installation may range from $150-$300. So, the total initial investment is $450 to $900 to get a fan and install it on the roof.
The number of fans required depends on the size of the attic. In case you buy two solar fans, the expenses may shoot up to $750 to $1500. There may be additional costs to get the permits and other stuff.
2) Low monetary saving
After a heavy sum of money is invested one may expect the saving would be in huge amounts as well. However, for a 1000-square-foot-air-conditioned house having two solar roof fans saved approx. 460kWh of energy in a year. So, the savings for a year are only about $40, which is less than expected.
3) Leaky Roof
For installing a solar fan in the attic, a hole needs to be cut in the roof. The more the number of fans, the more the number of holes. But if the hole is cut improperly or not maintained correctly, it can be open for leaks. There is a high risk of such leaks if the installation is done by a layman. However, hiring a professional to complete this task can minimize the risk of leaky roofs.
4) Low Air movement
The solar fan may prove to be eco-friendly but is not as powerful as the traditional electric fan. It may be discovered that the solar fans do not have enough strength to push the warm air out of the attic as expected. Hence, there might be a need to combine solar fans with passive flow options to keep the electricity demand low. The solar fans are only capable of pushing the air around the hot and humid air in space instead of exhausting it. So, the investment may not prove to be worth it.
5) Needs sunlight
Most of the models do not have a battery backup to power the fan in the absence of sufficient sunlight. The fan stops spinning the moment it loses contact with light. Therefore, the presence of dust or shade trees can affect its output. This means that in such situations, the attic will not be cooled, which will warm up the house as well, with no possible way to get rid of the problem. The installation of solar fans may not be beneficial in regions that receive only a few days of sunshine per year.
6) Less powerful than an electric fan
Generally, solar roof fans have a CFM rating of up to 1200 CFM, but a traditional electric vent can have a high rating of up to 1600 CFM. This means the solar fan cannot push much attic fair out as opposed to an electric fan.
7) Change the roof structure
A solar fan cannot be installed without cutting a hole in the roof. For a large-sized attic, there might be a need for more fans to be installed, which means creating more holes in the roof. Apart from this, the total weight of the installation could disrupt the supports that are present on the top of the house.
8) Long time to recover the initial cost
By choosing an Energy Star-rated solar fan, you can qualify for the tax credits which equal up to 30% of the initial expenditure. As there will be a need for two fans at least to get results like a single traditional electric fan, the expenses will shoot up. According to HGTV, to cool a home of 1,000 square feet with solar roof fans, about $40 per year in a warm climate like Florida can be saved. This means it may take 10-15 years to recover the initial investment.
9) Number of Fans
The number of fans required to effectively cool down the attic depends on the size of the attic. One solar fan can push 800 to 1200 CFM of air. An attic of 1,000 square feet needs approx. 700 CFM, whereas attics with steep or darker roofs require 15% higher CFM. The solar fan can prove to be effective only when it meets or exceeds the CFM requirement of the attic space.
10) Makeup air
When the passive vent or the makeup air in the attic is not sufficient, the solar fans will draw the conditioned air from the main regions of the house. In such a situation, the cooling of the entire home gets disturbed.
Summary
So, there you have it – 10 pros and 10 cons of solar attic fans so that you can have a balanced decision before you go for one. To sum it up, a solar fan is more costly than a traditional electric fan and may also not prove to be effective in terms of energy output. The installation is easy but involves the risk of creating a leaky roof as well. The solar fan enables you to have a sustainable lifestyle with aesthetically impressive ventilation. However, it may take 10-15 years to recover the initial investment, hence it is important to check the need before purchasing it.
Frequently Asked Questions
Solar roof fans may not prove to be as effective as electric fans. To get an output like an electric fan, more solar fans need to be installed.
Solar roof fans can last up to 20 years, just like solar panels.
Since solar fans are dependent on sunlight, they cannot work in light. Also, unlike a solar panel, most solar roof fans do not have a battery backup to function at night.
