The amount of CFM or CMM needed to cool an area is about 3 to 4 times the area.
You might be interestedYou can use a conversion calculator to easily switch between measurements.
You are watching: Outdoor Fan Blades
Larger Outdoor Fans Aren’t Always Better
Consider using a combination of outdoor fan styles. A small ceiling fan can be used to cool the middle or one side of a patio and a standing fan or table fan can reach the corners.
An open area will allow that moving air to cover as large an area as possible, but will also allow it to dissipate. For example, a canopy or gazebo that’s open on all sizes will likely need a larger fan than the same sized area closed on two or more sides. A good general rule to determine how many outdoor fans to use in an open area is that you want to create some air movement where most people will be most of the time.
Since there are no walls or ceilings in completely open areas, you will need to use a free-standing fan such as a pedestal or standing fan, a floor fan, or even a table fan sitting on a wall or ledge.
Read more : How To Keep Cats Off Outdoor Furniture Cushions
Especially with floor fans, the air flow originates low to the ground, meaning people moving in front of it can more easily block the airflow. You can lower the chances of that if you use an oscillating fan, or several fans set up around the area to “bathe” it with moving air.
How Many Blades Should An Outdoor Fan Have?
Is a 4- or 5-blade ceiling fan better?
Three is generally the most efficient number of fan blades for outdoor cooling. Four to six blades are usually used because the extra 1 to 3 blades make for a quieter fan. More blades than six is almost always less efficient, but it can be more decorative – especially important for ceiling fans. Fewer than three blades don’t take advantage of a motor’s power and move less air. Choose a three-blade outdoor fan when noise level is not as important but cost and efficiency are crucial.
Any more than six fan blades can put more strain on the motor than the resulting air movement would justify. The exceptions are specialty outdoor ceiling fans that may use up to ten blades and extend 24 feet across. These use a combination of specialized outdoor ceiling fan blades and motors.
The Shape of the Fan Blades
The wider the blade, the more air it will move … up to a point. The fan blades on some very decorative fans can be so wide they would nearly overlap each other. This may not allow enough air in between the blades for good air movement. If beauty is more important than maximum airflow, these can be a fine option.
Some fans have just the tips of their blades tilted. This doesn’t “even out” the air flow the way tilting the entire blade does, but it can enlarge the area a fan affects. This is often seen in standing fans.
Still, other fan blades have specialized shapes. Some are shaped like airplane wings with more surface area on the top than on the bottom. Some curve forward. You may need to contact the manufacturer to learn how these special shapes affect the air flow.
Outdoor Fan Speed / Fan Blade Rotation
Read more : Why Are My Plants Leaves Turning Black? What You Should Know
Faster blade rotation is basic to greater airflow, which means greater cooling. Blade rotation is sometimes called “fan speed” and is measured in RPM (revolutions Per Minute). It is simply the number of times any one blade makes a full rotation in one minute. An outdoor fan with two speeds will have a lower RPM with less air flow on LOW and a higher RPM with greater airflow on HIGH. Look at the CFM / CMM rating for each speed.
Blade Pitch and Tilt
The angle at which the fan’s blades are angled up from the flat plane of their rotation is referred to as the “blade pitch”. The greater the pitch, the greater the airflow. But as pitch increases so does the drag. So as the pitch increases, so must the power of the motor. Blade pitch usually varies between 9 and 15 degrees. Very strong motors can drive blades with a pitch in the 20s which makes for exceptional air flow.
Some outdoor fans modify not only the pitch of the blades but also their tilt. Tilting the fan blades back (or up, in the case of ceiling fans) distributes the blowing air more evenly around an area. So there’s less airflow directly in front of the fan, but more in the outer reaches of the fan’s airflow. The airflow is “evened out.”
Blade Materials
Fan blades should be made of sturdy, warp-resistant materials. An outdoor fan, being exposed to much harsher elements than an indoor fan, needs to have blades that resist corrosion and warping. The most common materials are aluminum and various kinds of plastics, such as ABS. Heavy-duty fans may also incorporate fiberglass into their plastic / polypropylene blades.
Materials like rattan and most woods won’t hold up to long periods of outdoor use. But aluminum and plastics can be treated to look very much like them and still be durable enough for outdoor use.
A common cause of drooping fan blades is simply attachment screws that loosen over time. This can be fixed by tightening the screws with an ordinary screw driver. But when the material, itself droops or warps, the fan blades may need to be replaced. Look for lightweight, durable blades that are the same size as the original blades.
Source: https://gardencourte.com
Categories: Outdoor
