When summer temperatures record triple digits, the last place you want to be is in your attic. Having a closed-off attic will be not good for your cooling and heating system, right? Would it be great if you can vent that hot air out and remove it entirely from your house?
This is where the solar-powered ventilators can help you. These devices are designed to keep your attic cooler and help lower your overall energy cost. However, this has remained controversial among the professionals in the building industry because there’s no clear evidence on how effective these devices are or whether they are safe to use. In this article, you’ll find out the ins and outs of using these machines and understand how they are different from your home ventilation system.
A Brief History on Powered Ventilators
Before we go into the specific details of the solar-powered roof vents, let us first understand what attic ventilation is. This topic may not be something that you get to talk about often, but this is important for your home health.
Powered ventilator experts have said that these devices can extend the life of your roofing and helps to prevent the growth of mildew in your attic. Furthermore, the device also helps to make your home less susceptible to molds while minimizing the buildup of ice during winter. The main purpose of the powered ventilation system is to minimize heat gain across the roof and ceiling of your home and prevent the moisture from condensing in these areas. This is extremely important because according to studies, most of the houses in the US experiences excessive humidity.
Keeping your attics dry and well ventilated can help to stabilize the temperature in your roof and reduces the chances of mold, deterioration, and rot.
However, not everyone would agree with these claims. There are some roofing professionals who would say that instead of helping to lower the temperature in your attic, the powered ventilators would instead bulk-up your energy expenses since it sucks the cool air out of your home and this will funnel electricity off the grid to get things done.
On the other hand, every time you increase the number of openings of your roof to install the ventilator, you’ll increase your risk to leaks, and this could counteract with the ventilator’s moisture-reducing abilities.
Building oversight and research groups generally believe that more studies are needed to dismiss or backup the humidity and temperature claims of the device. This is because some of the initial studies in this area have shown some flaws, such as leaky ductwork, as well as limits because of the weather conditions and time constraints. A much better approach is to take into consideration the ventilation system of your home in the same way that you would on the cooling and heating system. It should be equal to the size and demand of your home.
What’s a Solar-Powered Ventilator Exactly?
Among the disagreements about the attic fans and the ventilation system has something to do with the confusion on its terms. It’s important to define the exact difference between the powered attic ventilators and the whole house attic fans.
Attic fans are designed to keep your homes cool at night. It usually works along with large passive vents at the rooftops and draws warmer air indoor, towards the attic where it gets exhausted into the roof vents. The windows in the downstairs are usually left open to allow for the cold nighttime air to get in, which helps to lower energy expenses.
On the other hand, powered ventilators are not a type of home cooling system, yet they tend to get confused with the whole house attic fans since they are technically fans and have similar goals and that is to reduce the overall cooling demand in a house. As a result, energy consumption will be lowered, and the attic will be ventilated. However, instead of cooling the entire house, the powered ventilators will work by exhausting hot and humid air from the attic. This method allows the cooled air outdoor to fill your home via the soffit vents. The system is usually attached to a thermometer responsible for turning the fan off and on, whenever the heat in the attic would increase above a specific temperature.
It sounds awesome, right? However, there are certain factors at home that could throw the equation off. For instance, if your attic is not sealed properly, the ventilator could pull the air-conditioned air into the gaps and will bring it outdoors. This will increase the heat in your home instead of reducing the need to use the air conditioning system. Furthermore, the ventilator can also depressurize your attic interior, and according to some findings, this could increase the carbon monoxide in your home, as it will make the water heaters to backdraft.
The solar-powered ventilators have been made to counter the claims that electric-powered roof vents are saving energy. Because the fans were powered naturally, they would not be sucking energy off the grid, which negates any energy savings resulting from better ventilation. A team of researchers from Florida Solar Energy has tested the solar-powered ventilators, and they have discovered that they did have a positive effect on home energy and reduced the homeowner’s dependence on air conditioning system.
However, some energy experts would still maintain that the savings represented by the solar-powered ventilators, which is said to be $37 per year, would not be enough to recoup the cost of getting the equipment installed, which averages at $850, excluding the labor cost.
Are Solar Attic Fans or Roof Vents Really Worth It?
Just like with the other green home renovations, the answer would be, “it depends.” They are certainly not recommended if you’ve got combustion gas appliances, such as the gas-powered water heaters because there is a potential for backdrafts. However, if your goal is to make your home energy efficient, regardless of the cost you’re going to incur, then this equipment can be a positive addition. This is especially true if you wanted your attic to be cooler. For instance, you are using it to store valuables that you don’t want to expose to humidity and heat.
Also, if your house tends to suffer from excessive heat from your attic, installing the solar-powered ventilator is a potential solution to lowering the temperature inside your home and keeps your roof protected.
Other Ways to Cool Your Attic and Optimize Your HVAC System
If the attic in your home is feeling stuffy and humid, and gets excessively hot, using the powered ventilator is not the only option. As a matter of fact, coming up with a well-designed ventilation system can do the job just as well. To allow for an adequate amount of air to flow into your attic, half of the vents must be placed high into the rooftop. If possible, at the topmost peak, while the other half should be placed at the roof’s lower portion. This can help to create a natural circulation of air, allowing for the hottest air to rise into the much higher vents.
Proper sealing and insulation can also help. Filling the cracks in the ceiling can help prevent the cool air from seeping towards the unconditioned attics. Once you have sealed up these areas, consider adding insulating to the flooring of your attic.
If the HVAC system of your home runs all throughout the attic, you’ll be able to experience better performance once you move the ductwork towards your home interior. That way, you no longer need to worry about how hot the attic can become. Ensure that the seals in between the ducts are closed properly to keep the cooling and heating system from leaking.
These changes can help to improve your HVAC’s efficiency all throughout the entire year and not just during the hottest months.
However, if you’re interested in the use of solar ventilators because you find it appealing to moderate your roof temperature, then there are some “low-tech” solutions that you can apply to keep the temperatures down. First, consider the use of lighter-colored roofing. Darker roofs tend to absorb more heat. Lastly, consider planting some trees in your surroundings. This will provide you with long-lasting benefits, including shadier roof, and above all, it can help to improve your home’s façade as well!
Choosing the Right Solar Roof Ventilator
Although the manufacturing cost of solar panels is decreasing, a high-quality solar panel and motor are often the most expensive parts of the solar roof ventilators. You can expect to pay around $500 to $900 for a product that’s guaranteed to last. Compared to the recommended 2 to 4 whirly birds, which costs $200 each for a standard size home, a Single Solar Star is definitely worthwhile.
There have been lots of performance claims on the market. However, the solar-powered roof ventilation is going to make a huge difference, unlike the wind vents. So, what are the important factors that you need to take into consideration when buying the roof ventilation?
The best way to determine is to understand the solar panel’s wattage as well as the diameter of the extraction fan. Although there are other variables, this should be the easiest comparison.
Although it is typical to offer a warranty of 10 to 15 years for the solar panel, make sure you review the fine print. Most warranty will include the components, usually offering 1 to 3 years of warranty for the motor.
With the various imports being directly shipped from outside the country, customers must be careful with choosing the right product to use. A single and one-size flashing can lead to similar issues of leaking like the traditional and low-quality skylights. Consumers must choose the flashings that are custom-made to fit with the contours of their roofing.
- Market Prices
Wind vents cost between $80 and $350 per unit.
Average air volume is tested at about 80 to 100m3 per hour, and this is relatively inefficient. Usually, these products have the same performance as that of a static cap. They are in high demand in the Australian market since they are cheaper to include in roofing and insulation packages.
The main factor in the pricing of the wind vents is quality.
Here’s what you should look for:
- Does it come with a fan blade – the blade is extremely helpful regarding improving air extraction.
- What about the diameter of the product – for domestic homes, the diameter usually ranges from 250 to 350mm.
- Warranty – the bearings is one of the most important concerns on wind vents. You’ll see several low quality wind vents that have bearings that produce annoying sounds.
Budget Solar Roof Vents Cost $100 to $250 per Unit
When looking for a solar powered product to buy, you should be ready to spend a bit more for a high-quality system. Budget roof vents that are solar-powered are usually cheap because they are made from poor quality solar panels and motors. This could lead to poor performance of the product, providing little to no benefit unlike with a standard wind vent that usually comes with a warranty. If this is your budget, you might as well stick to a high-quality whirlybird.
Quality Solar Roof Vents Cost $500 to $900
We’ve already talked about how to choose the proper product type. But what about the most common questions and requests?
How Much Can Roof Ventilation Lower My Home’s Temperature?
This question is almost impossible to answer since there are lots of factors to consider such as the roof material, insulation, and the tiles. The best way to find out how the ventilation is going to work is to place your head into your roof cavity and try to feel the temperature. The temperature on your roof cavity could reach 60 plus degree easily, so replace this air with a much cooler air from the outside.
How Many Eave Vents to Install?
There are various recommendations when it comes to this. However certain factors like sarking on a tiled have the most major impact. One way to identify this is by opening the manhole at your ceiling. If you’re still feeling a substantial amount of air getting drawn into the manhole even after the ventilation has been installed, then you probably need more eave vents.
Do They Operate at Night?
Most of these devices work in the same way as the whirlybird, however, instead of working along with the wind, they operate using the sun. The whirlybird will not work during a hot and still summer day, while the solar roof ventilator will not motorize at night. Wind vent has the same performance as that of the static cap. The solar roof ventilator would still allow for natural air at night.
- Batteries can’t work well with extreme temperatures – There have been several recalls for battery-operated roof products due to fire hazards.
- Batteries usually come with a one-year warranty, but depending on the quality, the batteries must be checked from time to time and replaced at least after a year or two.
- Battery backup – This needs to be requested, however, you must be aware of the pitfalls and consider the extra costs.
The Solar Star can still operate enough to bring in moisture from your roof cavity. However there’s little need for the device to run in full capacity. Roof ventilators often draw air from the outside, and the conditions of the outside air will determine its impact on your home.
What You Should Know About Whirlybirds
Without proper ventilation or insulation, a standard roof space traps and accumulates heat, as the sun will get into your roof. The heat radiates towards your ceiling to warm your home. This accounts for 25 to 35 percent of heat gain during summer. It’s obviously possible to install blinds to block the heat on your windows. However, you cannot place blinds over your roofing.
Once the heat in the roof starts to seep into your ceiling, your home will become hot and stuffy. Normally, homeowners will resort to air conditioning, although unventilated roof spaces will continuously transfer heat. If you don’t have the means to keep your home cool longer, your electric bills will surely skyrocket.
Over the past years, the process to ventilate your roof has drastically changed. The product that most homeowners are familiar with is the roof whirlybird. Samuel Ewart made one of the first few designs of the whirlybird in 1910. The design principle has not changed much in decades since it still relies on the wind in producing turbine spin. They could also rely on the expansion of the air in your roof cavity resulting from the rising temperatures.
How Do Whirlybirds Work?
The whirlybirds are available in two types – conventional wind-driven and the mechanical, active-powered. The more popular of the two is the conventional whirlybird that works according to the wind. Once the wind hits its turbine fins, it will trigger the vents to rotate. The motion will create a vacuum that would suck the air out of the roof. However, a single whirlybird may not be enough for a modern home and would require up to 6 units before you could feel the effect.
It’s worth it to note that these devices can help to reduce the buildup of heat and humidity while improving the circulation of air inside your home. The design can also help to resist rain, although this is not impervious.
Is a Whirlybird Effective?
Depending on the manufacturer of the whirlybird, as well as the model that you have chosen, each average unit is capable of ventilating 100 to 150 m³/h in a 12-km/h winds. However, the performance will naturally vary from one design to another. These factors will range from how warm the air in your roof space, wind accessibility, throat size of the whirlybird, and the wear and tear of the unit itself.
For you to feel the full effects of ventilation in your home, you need up to 700 m³/h of airflow to keep the space in your roof stay at near ambient to the temperature outside your home. But this also means that you will need more than one unit of whirlybird to be able to do the job well.
Using Ventilation for Commercial Purposes
Whirlybirds that are intended for industrial use need extremely strong winds to be able to operate somewhere between 2,500 and 5,000 m³/h for every hour, while the average unit needs only around 8 km/h to provide satisfactory performance.
Although the solar roof ventilation systems are mainly intended for home use, we also offer units for commercial use. They were properly designed to ventilate extreme heat, which large-scale properties tend to produce. Also, the commercial exhaust fans are great at adequately ventilating fumes on commercial properties.
Dedicated Roof Ventilation
Conventional whirlybird is old school. Its aging design has now been replaced by a far more effective and highly dedicated ventilator system. While they are still being produced nowadays and can be seen at various homes, more and more homeowners are turning into solar roof ventilation to meet their home extraction and cooling needs. Documented studies have also shown that most of the modern roof ventilator system casts a shadow over the cheaper version of the whirlybirds.
The Solar Whiz ventilator is ideal for DIYers. It’s also free to operate during the day, although it also comes with nighttime options. It’s also available in a wide variety of sizes, depending on your needs. They could easily out-perform 15 to 20 units of whirlybirds.
The old concept of using wind in ventilating a roof space is now declining. Besides, why do you need to rely on the wind in ventilating your home if the issue is the sun? So use the sun to your advantage instead! Invest in a solar roof ventilator that can help to keep your home comfortable in summer.
Solar Roof Ventilation vs. Whirlybird
For instance, you own a business, and you’ve got to choose between your two employees – one employee shows up to work regularly and produces consistent and reliable work results while the other employee will only show up now and then and provides variable work results. Of course, you’ll choose the first employee since he can offer the most benefit to your business.
Choosing between the wind-powered vent and the solar powered ventilation system is like the situation above – the wind vents will only be effective if the wind is available. Although occasional wind breezes are a joy to have especially when you’re spending some time outdoors, this is not going to do much when it comes to improving the humidity and hot air in your home.
On the other hand, the Solar Star roof ventilation works using a solar-powered fan capable of moving a large amount of air at any time when the sun is shining. In fact, it works even on partly cloudy days and during those days when there’s no wind at all. During the midday heat when there’s not much air moving, the solar-powered fan is still hard at work. The device also eases the burden of the air conditioning system, which means that the unit will not have to work as hard and this results in energy savings!
Why is Consistent Air Movement Important?
During the hottest months, the space in your attic could reach a temperature of up to 60-degree. And although hot air would rise, once it gets trapped in your roof, it will wind up heating the air at the lower floors. The trapped heat could lead to significant problems in your roofing and will cause extreme heat damage to your roof shingles and underlay. Also, if the weather will turn humid, the air inside your attic could get damp, providing for an ideal place for mildew and mold to grow.
By keeping the air to circulate in your attic and give it a place to escape, you’ll be able to maintain your roof’s integrity while improving the level of comfort inside your home. Furthermore, by taking away the damp and humid air and encouraging the movement of air, the ventilation system can significantly help to prevent damages in your home, most especially the growth of unhealthy mold.
How Good is the Solar Star Ventilation System?
The Solar Star is extremely good. As a matter of fact, comparison testing of the device and traditional wind vents using the Australian Standards during the calm sunny days has resulted in the removal of humid and hot air in a rate of 1080m3/hour – 1800m3/hour, which is about the same amount of 10 – 15 wind vents! This means that you may need to cover your entire roof with the vents to get the same effect.
If you want an economical way to keep your home healthier, drier, and cooler, the Solar Roof Ventilation system should be number on your list.
Comparison Between the Two
The whirlybirds have been around since forever. But lately, there have been some discussions regarding solar-powered roof ventilation system.
So what’s the hype over these solar fans?
At the moment, the focus is on the volume of the air that gets moved by the different roof ventilation fans available.
The average whirlybird moves at 100 cbm per hour, at a wind speed of 12 km/h. It’s difficult to find this kind of data from the manufacturers of wind-driven fans, although there seems to be a consensus when it comes to studying the different options for solar-powered roof ventilation that they’re equivalent to about 10 – 30 whirlybirds.
The only wind-driven fans that have capacities almost similar to the solar roof ventilation are the industrial whirlybirds. These devices are available in a wide variety of capacities and sizes. But then again, it’s hard to find the data that can support this.
The most well-known industrial whirlybird in Australia is the Edmonds branded at 900 mm with a capacity of 2700 cbm per hour at a wind speed of 12 km per hour. The biggest problem is that they mainly rely on wind. And as you know, it may not be too windy during the hot summer days when the ventilation is needed most.
Currently, it’s somewhat unusual to see industrial type whirlybirds being used at residential homes and offices, retirement villages, day care institutions, etc. You will only find these extremely large units in warehouses and factories.
However, if you prefer the roof ventilation that’s wind-driven to match the solar ventilation alternatives, you may need to check the extremely large industrial whirlybirds.
The biggest benefit of using whirlybirds is that they are cheaper to purchase. Yet, these devices would also incur installation costs. Those whirlybirds that are for residential use are quite easy to install, but if you’re not capable of doing it yourself, then you need to pay for the installation cost. The cost of installation could be several times the cost of the unit itself!
The Solar Roof ventilation system may be more expensive. However, they are up to 30 times more effective. To circulate enough air to improve the temperature in your roof space, the whirlybird will unlikely make any noticeable difference to both the roof space temperature as well as the amount of heat that radiates through the ceiling of your house.
If you consider the cost of buying 10 whirlybird units versus one solar powered roof ventilation system, the numbers will not stock up favorably for the whirlybirds, most especially if you need to hire a professional for the installation. Thus, the solar roof ventilation system is far more valuable if you need power and wanted to make a serious difference in the changes in the airflow in your house.