On a quiet, blue-sky day, spending time outside is almost mandatory. Yet, these are invariably hot days, so it would be great to add a cooling device to your porch. Installing an AC out here would be completely useless—and very costly. Ceiling fans, however, provide a cooling effect in a completely different manner.
Because of how they function, ceiling fans are likely the solution you are looking for. However, there are considerations in choosing and placing the fan.
Ceiling fans are one of the most effective ways of providing cooling outside because the cooling mechanism relies on the movement of air over skin as opposed to the cooling of the air itself. Size, position, and weather rating are important to the effectiveness and safety of outside ceiling fans.
How Ceiling Fans Work
Unlike air conditioners, ceiling fans do not actually cool the air in a room. Instead, they move the air around. They do this by rotating pitched blades.
The performance of the fan is usually dependent on factors like the number of blades, the size and design of the blades, the speed setting, the fan’s capacity, and the blade direction.
By default, ceiling fan blades spin in a counterclockwise direction. This movement of the blades draws the air above and around the ceiling towards the fan. In this direction, the pitch of the blades directs the air downward.
The downdraft results in a wind chill effect.
A wind chill effect is a perceived drop in body temperature because of an increase in airspeed over the surface of the skin.
As the air passes over your skin, it sweeps away the heat trapped there. You feel cooler without this layer of heat against your body. Additionally, your body is able to lose more heat through your skin once the insulating air is moved.
If you are sweating, the flow of air over your skin will also allow you to benefit from evaporative cooling.
Some fans have a reverse switch that allows you to change the blade direction from counterclockwise to clockwise.
In this direction, the pitch of the blades pushes air up toward the ceiling, displacing the “warmer” air here. This air then flows down the sides of a room or space and around the occupants of the room/space.
Ceiling Fans Are Effective Outdoors
Cooling systems like these typically function by drawing in hot air, removing the heat, and releasing the cooled air. Therefore, for optimal results, it’s recommended that you close every route through which conditioned air can escape or unconditioned air can enter.
Outdoor areas aren’t enclosed by walls and are usually exposed to the elements, so installing air conditioning would be a waste of money and effort.
Ceiling fans, on the other hand, do not remove air from a room, so there isn’t a risk of losing conditioned air to the atmosphere if they are installed outdoors.
Their mode of operation makes ceiling fans one of the best ways to stay cool outdoors.
One thing to keep in mind is that the atmospheric temperature influences the effectiveness of outdoor fans.
While the actual movement of air over your skin is the main cooling method, if this air was cooler, the effects would be enhanced.
Besides their cooling effect, installing a ceiling fan outdoors has the added benefit of keeping pests away. This makes for a more comfortable lounging experience, especially if you enjoy staying outdoors late into the night.
Ceiling fans also add character to a space, and if you purchase one with lighting, it will provide extra illumination to your outdoor space.
Factors Influencing Effectiveness
If the distance between the blades and the ceiling is less than 12”, the fan would not be able to effectively move air around.
As a general rule, there should be a minimum of 7’ between ceiling fan blades and the floor. Failing to adhere to this rule would put you and passersby at risk of getting injured by the fan.
Besides the safety concern, the distance between the fan and the occupied area also influences how well the fan circulates air.
If the blades are too far from the people it is supposed to be cooling, the breeze might be lost before it reaches you.
For optimal airflow, the distance between outdoor ceiling fan blades and the floor should be between 8’ to 9’.
If your ceiling is very high, rather than using the downrod that came with the fan, you can purchase a longer rod to help reduce the distance that the air has to travel before flowing over people.
The size and layout of the space also influence how well an outdoor ceiling fan performs. For instance, if your fan is too small for the space, it wouldn’t have much cooling effect. So, it’s best to take the square footage of the space into consideration while purchasing the fan.
Ceiling fans installed in outdoor spaces that have at least some walls perform better because rather than being lost to the atmosphere, the walls cause the breeze from the fan to bounce back, resulting in improved cooling.
The CFM (cubic feet per minute) rating determines the volume of air the ceiling fan is able to move around in a minute.
If you are yet to purchase your fan, it’s essential that you purchase one that is ideal for your outdoor space as it plays a huge role in determining how much satisfaction you get from your ceiling fan.
Bigger fans typically come with higher CFM ratings and whether a fan is appropriate for your outdoor space or not would depend on the size of the space.
If the CFM rating is too low for the space, the fan will not be able to move around enough air, which means that it wouldn’t cool you properly.
Another factor that influences the performance of outdoor ceiling fans is the speed of air movement. This determines how fast the fan moves air and is measured using rotations per minute (RPH) or miles per hour (MPH).
Sizing a fan for outdoor areas is a little different to sizing it for an indoor space. If you were to compare it to indoor standards, you should always oversize for the outdoors.
Blade Size and Design
Although the effectiveness of an outdoor ceiling fan is ultimately dependent on its motor, the composition of the blades also influences how well the fan moves air around.
The elements of ceiling fan blades that affect airflow include:
- The blade’s pitch, which is the angle the blades are set, is a key factor in determining how much air a fan can circulate through an outdoor space. The greater the blade pitch, the more air it is able to move (to a certain point; after this, resistance becomes too great to affect any further benefit).
- The blade’s span also influences airflow. Shorter blades create a narrower, more forceful airstream directly below the fan, so they are only effective in smaller spaces. Larger blades deliver slightly less forceful airstreams over a greater radius and are better for large spaces.
- The number of blades influences how much air the fan is able the move around. Ceiling fans with fewer blades typically circulate air better because more blades increase the drag on the motor, causing the fan to circulate less air. However, this is only true to a certain extent.
Do You Have to Buy an Outdoor Ceiling Fan?
If you intend to install a ceiling fan outdoors, then you most definitely need to use a fan specified for use outside.
Here are some of the features that distinguish outdoor ceiling fans from their indoor counterparts.
The Ceiling Fan’s Rating
Ceiling fans are rated by the Underwriters Laboratories (UL) based on their installation location.
A fan can either be dry-rated, damp-rated, or wet-rated.
All indoor ceiling fans are dry-rated and outdoor ceiling fans are either damp-rated or wet-rated.
Outdoor fans are specially designed to withstand the elements.
The level of weather resistance of an outdoor fan is dependent on its rating.
Damp-rated fans can only withstand a fair level of moisture exposure, so they are ideal for outdoor spaces that aren’t directly exposed to the elements, while wet-rated fans can withstand direct exposure to the elements.
Exposing indoor fans to moisture would not only lead to physical defects, but it can also damage the motor and worse can become an electrical fire hazard.
The quality of ceiling fan materials varies from one fan model to the next. However, because outdoor fans are exposed to harsher conditions, they are usually made from sturdier and more durable materials.
The motors of outdoor fans feature a weatherproof seal that protects motor components from moisture exposure.
While indoor fans do not have any form of weather protection, the components of damp-rated fans are crafted from weather-resistant materials and wet-rated fans are made with weatherproof materials.
Cooling an outdoor space requires more air movement than indoor locations, so manufacturers sometimes use wider blades for outdoor fans. Outdoor blades are also crafted with steeper blade pitch.