Restaurant, Bar, Cafe, Pub and Shop Ceiling Fan Buying Guide
Here we provide you with the essential facts to assist you in selecting and buying the right ceiling fan for your business. As we all know buying the cheapest is often a false economy that costs more in the end whereas investing in a more expensive fan will mean making an investment with a higher capital price to start with but reap dividends and save money down the line. It is therefore important not to waste this extra investment and to educate yourself with the basics of buying a ceiling fan. Ceiling fans are a wise investment and should provide paybacks of 6 months – 1 year depending on how they are used.
How does the air from a ceiling fan flow around the room?
The diagrams below shows the direction of airflow in the summer ie for cooling, and the approx positioning of the fan within the room. In the winter months the ceiling fan direction can be reversed which makes the flow direction the opposite and brings heat that is trapped in semi-stable layers at the ceiling back down to floor level saving energy.
What is the most energy-efficient number of blades to have in a ceiling fan?
This is an often asked question and we have seen many conflicting answers around on the internet as to which is more energy efficient a high or low number of blades. To get to the correct answer we need to consider fluid dynamics and the key principles without getting into the complex mathematics of fluid flow equations.
The standard drag equation is: Drag Force is proportion to density x area x velocity squared However this only applies when the velocity is reasonably high and fluid is flowing turbulently. At slow speed the fluid is not flowing turbulently but smoothly in what is known as laminar flow. In this regime the drag for equation according to Stoke’s law is Drag Force is proportional to just the velocity x area. So a blade that doubles in speed in the laminar flow regime will need twice the power whereas a blade that doubles speed in the turbulent regime will need four times the power. Conversely, for a given power the slower the flowrate the better for the turbulent flow but in laminar flow it makes no difference. Since ceiling fans in general have large blades and rotate at between 50-200 rpm they are going to be operating mainly in the laminar regimes. This will be assisted by the shape of the blades with propeller shapes being far more efficient than flat shaped.
For higher speed fans operating in the turbulent flow regime – Consider the flowrate in terms of quantity of air moved per minute, Q. Since the air is effectively pushed by the blades the more blades and the faster that they move will increase Q. For a given motor duty it can only deliver the same maximum power which gets converted into air movement and heating up the air due to the turbulence and drag (resistance). Adding more blades shares the pushing load and so to deliver the same Q will only need to rotate slower, which in turn reduces the drag on each blade. The crucial difference is that despite have more blades to add to the total drag the effect is more than offset by the large reduction in drag/blade due to the square relationship of the slower speed.
Motor power and blade speed – The motor speed increases until the drag force equals the motor force. So a fan with the same size blades with 1 blade will move 3 times the speed of a 3 blade fan and so move the same Q in the laminar regime will be exactly the same flowrate. In the turbulent regime however it will be less efficient and experience more drag slowing it down until equilibrium is reached. The amount of air moved will reduce considerably going from 3 to 1 blade but not so much going from 5 to 4. There will be some additional wind noise associated with faster moving blades but if the speed is kept low this will be avoided but at the penalty of Q.
In conclusion – since most ceiling fans operate in the laminar regime the difference really boils down to one of aesthetics. Small bladed ceiling fans with badly angled blades can operate in the turbulent zone and so waste energy (equally oversized motors with small blades can result in the same). A good brand of manufacturer will ensure regardless of the number of blades it is designed for optimal air delivery with the angle and shape of the blade designed to minimise turbulence.
How do I know what is the correct size of fan to purchase?
You need to choose the right size fan for a room to get optimum comfort and energy savings. If the fan is too small for the room, it will not move enough air to make you feel comfortable. If the fan is too big, it could move too much air. Hunter recommends the following:
Hunter recommends slightly smaller sized fans as per the table below due to their more efficient performance. These should be taken with a pinch of salt and in our experience it is always better to oversize than undersize so that you have something in reserve for those really hot days and in normal operation the fan can be run on medium speed thus avoiding any wind noise.
|For Rooms Up To:||Fan Blade Span:|
|100 sq. ft.||36″|
|144 sq. ft.||42″|
|225 sq. ft.||44″ or 48″|
|400 sq. ft.||52″ or 54″|
|485 sq. ft.||56″|
|625 sq. ft.||60″|
How do fans cool the room? – Do they actually lower the temperature?
A ceiling fan cools by creating a wind chill effect; it does not lower the room temperature. Wind chill effect makes you feel cooler by accelerating the evaporation of perspiration on your skin. It is the feeling you get when you open the window in a moving car. If you have a ceiling fan in a room whose temperature is 80 degrees, running the fan can create a wind chill effect that makes you feel as if the temperature is 72 degrees. When used in conjunction with an air conditioner, a ceiling fan can lower energy costs, because you can set the thermostat of your air conditioner at a higher temperature.
Can the fan be used in the winter for any beneficial purpose?
A ceiling fan can help lower energy consumption in the winter by up to 10%. The temperature of the air in a heated room varies in layers; the air near the ceiling is warmer than the air near the floor, because warm air rises. A ceiling fan can help push the warmer air that is trapped near the ceiling back down into the room, thus de-stratifying the layers of warm air. As a result, the warm air is circulated where it is needed, and the heating system does not overwork to warm the room.
Which direction should the fan run in winter months?
The normal operating direction of a ceiling fan in the summer is anti-clockwise. To properly destratify a warmed room in winter, the ceiling fan should be run in the opposite direction ie a clockwise rotation. This pushes the air up against the ceilings and down the walls, to gently re-circulate the warm air without creating a cooling wind chill effect.
How much electricity will a fan draw?
On average, a ceiling fan run on high speed will consume less power than a 100-watt light bulb. Traditional AC type ceiling fans draw 60 watts and the newer brushless DC low-energy fans draw 3-25watts which is incredibly efficient and less than 5% of what an equivalent air conditioning unit would consume.
How much can I expect to save in heating/cooling costs?
A ceiling fan can save up to 47% on cooling costs, and up to 15% on heating costs. Savings will vary depending on local climate conditions and energy rates.
Can my fan be adjusted by remote control?
Most ceiling fans can be adjusted with an accessory remote control sold separately from the fan. In fact, remote controls can really enhance the performance and operating flexibility of ceiling fans since many include one-touch multiple speed settings, instant fan “off” operation, and full range light dimming — all possible from the comfort of your favourite chair or bedside table. Ceiling fan and light remote controls can easily be installed either with the fan during new installations or on fans which have been previously installed and in use for some time. The installation is an easy, do-it-yourself project and does not require any professional wiring. Remote control kits include a handheld transmitter for sending commands to the fan and a receiver which either conceals inside the fan canopy or mounts just beneath the ceiling. Remote controls can operate the fan or light reliably up to 40 feet away from the fan.
Can ceiling fans be mounted on angled or vaulted ceilings?
Yes, ceiling fans can be installed on angled or vaulted ceilings by using a fan canopy (the “cap” visible closest to the ceiling which covers the electrical box) which has been designed to accommodate sloped ceilings. Many quality fans will include this type of adjustable canopy, like Hunter’s Installer’s Choice® and HandsFree™ Canopy systems, but if not included with the fan at original purchase, accessory canopy adapters are sold separately at retail outlets.
Will the fan wobble?
Many factors can produce fan wobble. Substandard blade materials and improper blade sealing can produce blades that absorb moisture and warp – a prime source of wobble. Blades that are not matched in carefully weighed and balanced sets can also wobble. Inconsistent blade mounting brackets can create varying degrees of pitch (blade angle), throwing a fan into an unbalanced wobble. And poorly manufactured motors have rotors that can easily get out of balance, generating wobble from the very heart of the fan. Inexpensive mounting systems with pin fasteners can also contribute to wobble.
Hunter’s patented Anti-Vibration Technology (AVT™), featuring our unique, patented triangular hanger ball system, reduced torque for maximum stability and Wobble-Free® performance. The trilobular ball gives Hunter fans the ability to self-balance, eliminating wobble for rock-solid performance every time.
Will the fan be more prone to wobble if I use a downrod?
Using long-length downrods for fan installations actually help stabilize fans and reduce the potential for wobble. Think of a grandfather clock pendulum and its slow, heavy swing versus a smaller clock pendulum with a fast, unsteady swing. Weight and length combine to create stability, reducing wobble, whether it is in a ceiling fan or a clock pendulum.
Can a ceiling fan and a light kit be controlled from the same wall switch?
The answer here depends on how your wall switch is currently wired. If you have a single wall switch with two wires (one black, one white), the answer is “no” unless you purchase a control specifically designed for this type of switch (Hunter offers three models). The answer is “yes” if you have a three wire set-up in the single wall switch and purchase a more common, dual control that will operate a fan and light separately from a single switch. Having an electrician install a third wire can be expensive.
What is the difference being installed close to the ceiling versus on a downrod?
For maximum performance and greatest energy savings, ceiling fans should be installed approximately 8 to 9 feet above the floor. Extension downrods are used to properly position fans from ceiling heights greater than 8 feet. For example, a 12 foot ceiling would need a 3 foot downrod to position the fan at 8 feet (one foot must be allowed for the distance from the top of the fan motor to the switch housing bottom).
How quiet or noisy is the fan?
Many fans are noisy. An electrical humming created when a ceiling fan is running is usually the result of poor engineering design and a lack of precision or quality manufacturing. Some manufacturers use generic, inexpensive ball bearings to reduce cost, even though these are a common source of operating noise. A lack of proper dampening between metal parts can also create and intensify noise, as can the use of extra thin sheet metal motor and mounting system parts. Annoying hums are generated by low quality or inadequately sized capacitors which can start to breakdown after the year’s guarantee is finished. Inproper setting of the blade pitch can cause unnecessary air movement noise as well as wasted energy due to increased drag.
What causes a fan to stop working?
A number of possible faults can develop:
- Motor size and blade pitch are not specified and matched correctly.
- Improperly installed on/off pull chains can become faulty and be pulled out of the housing.
- Inadequate quality, testing, manufacturing and inspection procedures send poor quality fans to market.
- Defective motor windings can lead to electrical shorts in the motor.
- Low quality fan bearings may be “shielded” on one side only, allowing dust to enter and cause premature failure.
- Inexpensive materials, poor engineering, and substandard manufacturing processes are used to create “bargain” fans.
Hunter ceiling fans are known for their performance and powerful operation. It is the only manufacturer with an on-site UL-approved sound testing lab that allows it’s engineers to design for optimal performance on every ceiling fan.
Will the manufacturer stand behind the warranty?
Most manufacturers only provide 1 year warranties against defects in the motor. All of the brands that are sold by The Henley Fan Company come with either a 10 year or lifetime warranty even if the manufacturer doesn’t provide it. For example Hunter backs its fans with a lifetime warranty on the motor, and they back that warranty with 130 years in the ceiling fan business. Since the motor is the only moving part in the ceiling fan this is a real statement of confidence in a company’s product and you get the peace of mind of knowing you’ve got the best-backed warranty in the business!
What is covered by the fan warranty – how does the Hunter warranty compare?
Most fan warranties are limited warranties that cover just the motor parts for the stated life of the warranty eg a 20-year warranty will cover the motor parts for 20 years. Labour for the motor is generally covered for 1-year, as are parts and labour for all other components of the fan. The warranty also excludes accidental damage or damage from water ingress, damp (watch out if you are using it in a conservatory) or electrical power surges which happen far more often then you would expect. Since the motors built these days are extremely reliable with a very low failure rate this guarantee is not so crucial although we do get a regular stream of customers who have their fan motors failing. These are almost always down to damp or water ingress than a manufacturing fault but Hunter is very good at giving the benefit of the doubt and replacing such failures. We replaced 5 fans last year for a bar that had shown electrical failure, most retailers and manufacturers would have said “tough luck” but we believe in great customer service. All Hunter fans are backed by a Limited Lifetime motor warranty. Most importantly, Hunter is the only fan company in existence with over 115 years of experience behind its warranties.
What length down rod should I use with my fan?
A general formula for calculating down rod length is: ceiling height in feet minus 9′ = down rod length. This formula is based on the fan-to-floor distance of 8 feet plus 1 foot for the dimension of the fan. So if your ceiling height is 12 feet, you need a 3 foot down rod in order to properly position the fan 8 feet from the floor.
Too low and you won’t be able to use one due to the danger to tall people. Too high and you will need a drop rod to bring down the fan’s operating height to the optimum level (3m or 9ft). Use this diagram to select the correct drop rod length. Drop rods are not available in all lengths so just pick the closest to what is given below as they are only an approximate guide.
How do I select a ceiling fan?
Step 1. Select your product: Choose the appropriate size fan for the proper combination of comfort and efficiency. If you’re unsure about the room size, choose a larger fan to maximize your comfort at low/medium speed.
Step 2. What style and color do you prefer? For a coordinated look, match the blade finish to furniture or wood molding. Or select a fan body finish that matches door or cabinet hardware. Many fans feature reversible SwitchBlades®. A different finish on each side of the blade permits styling flexibility.
NOTE: Blade finishes are pre-matched to motor finishes. Blades are not sold separately.
Step 3: How high is your ceiling? – See above question
Most Hunter fans come with the Installer’s Choice® 3-Position Mounting System for installation versatility.
Hunter Low Profile® fans are specially designed for low ceiling applications. The motor housing fits flush to the ceiling.
If your ceiling is 9 feet or higher, you’ll need an extension downrod.
*Longer downrods must be purchased separately. 34° maximum angle.
Step 4: Do you need a light? Choose a fan with a coordinated light fixture included or customize the fan with your choice of accessory light fixture. All Hunter ceiling fan light fixtures are UL listed for installation on Hunter fans.
Step 5: Select a fan control. To operate your fan and light separately from a single switch without additional rewiring, choose a Hunter wall control. For convenient, easy operation in bedrooms and rooms with high ceilings, consider a wireless remote control.
Step 6: Select and buy your fan.
What tools will I need to install my fan?
Installation is a simple procedure and can be done by any competent DIY person. Electricity supply can be taken from an existing ceiling light socket. NB: Ensure that the electricity supply is isolated and double check with a meter before commencing the electrical work. The tools you will need are:
- Electric drill with 9/64 inch bit
- Standard screwdriver (magnetic tip recommended)
- Phillips-head screwdriver (magnetic tip recommended)
- Wrench or pliers
- Ladder (height dependent upon installation site)