ceiling fan efficiency

ANSI/ASHRAE/IES 90.1-2013 requires fans have a fan-efficiency grade (FEG), as defined in AMCA 205, Energy Efficiency Classification for Fans, of 67 or higher. The range of efficiencies for the larger fans, according to the label, is 51 to 176 cfm per watt for fans that are 49" to 60". They represent the year’s very best for energy savings and environmental protection. Now you're ready to head off to the store and buy yourself an energy efficient ceiling fan. Most fans are bought for decorative reasons, but I'm glad to see the CFM/Watt ratings. A fan with 48-inch blades typically consumes 75 watts, while a 52-inch-blade fan uses 90 watts. BTW, don't forget the other amazing benefits of ceiling fans: odor dissipation and insect retardant. Said box is hardly ever around when a rater does their inspection(s) and even if it happened to be in the trash container the day the rater shows up, it appears from your retail research that the efficiency listed is often the cfm/watt at the highest fan speed. This whopper is available in four different finishes but is shown with the ever-popular brushed nickel wet finish. I don't know what the testing requirements are but I'm sure they include proper installation. Air flow, whether you're talking about duct systems, bath fans, heat recovery ventilators, or ceiling fans, is measured in cubic feet per minute, usually called simply cfm. Every new ceiling fan being sold in the US these days … I've seen many installations where the short 8" rod is used and I could almost guarantee that the fan is not achieving optimal performance. Energy Efficient 52 Inch LED Ceiling Fan Next up is a 52-inch ceiling fan from Brightwatts, and this is a budget-friendly unit that comes with an elegant white-finished light fixture. That Farmington label seems a great example of fans law. Ceiling fan efficiency can be represented simply as Efficiency = CFM/Watt. One of the best ways to save money is to save on utility costs, especially heating expenses. 54" Ceiling … That's not the case anymore because every ceiling fan I looked at had a label on the box that tells you how much air movement you can expect for each watt of electricity you put into the fan. Jeffrey: Great points! Smaller fans take less of a hit than larger fans when mounted too close. Allison, Thank you. Your source of knowledge about the world of building science, home energy efficiency, green jobs and more. Ceiling fan airflow and efficiency are often overlooked, but the amount of air your fan moves each minute impacts the level of performance. The labels on the boxes I looked at all showed a box with three numbers, all specified for the fan running at high speed: the air flow (cfm), the rate of electricity use (watts), and the air flow efficiency (cfm/watt). For example, we could give the efficiency in terms of the rate of air flow per unit time (cfm) divided by the energy use per unit time (watts), which in fact is what we do. Ceiling fans increase energy efficiency by making people in a room feel cooler, not by cooling the air in a room itself. Though there is much confusion on the subject, it’s not that hard as long as you remember two simple rules. Allison, yet another awesome blog post! What this means is that for a fan handling standard atmospheric air with a density of 1.2 kg/m3 and a static efficiency of 75% the maximum pressure rise over the fan is 22.5 kPa. You may not have found them because they're sold under the name Windward. In many peoples eyes ceiling fans are chic and box fans are gauche. If you need more ceiling fan accessories, check out our ceiling fan light kits, ceiling fan light covers and our ceiling fan … Energy usage can be a bit confusing because of the whole rate versus cumulative quantity issue. Charles: Great points. But in a place like Houston when poor people have trouble with AC bills, the official stance of the electric company is they should use fans in place of AC. Provided the ceiling fan is properly sized for the room in which it is operating, its efficiency of moving air far exceeds that of an air conditioning unit, therefore, for peak efficiency, the air conditioner should be set to a low fan setting and the ceiling fan should be used to circulate the air. Fans don't cool the space. This bit of information is telling you what the expected range of efficiency should be … A few of the boxes had more energy data than the simple box shown above. The other ratings are needed in order to calculate the airflow efficiency of a particular ceiling fan. CFM is key when determining a fan’s airflow efficiency. I've been meaning to put up a post on the Haiku ceiling fan by BigAssFans. Sensors are located at the bottom of the cylinder to measure the wind speed. I wonder if anyone has seen numbers published, measuring what percentage of household electric use, is consumed by ceiling fans. This makes a HUGE difference compared to motor/blade design. Both will move about the same amount of air (neither will move much) while the 52" consumes more power. Electric space heaters typically devour 600 to 1,500 watts per room. This is another one of the fairly priced bladeless ceiling fans, whose … The wind speed is then converted into CFM (Cubic Feet per Minute). Fans should be installed so their blades are no closer than 8 inches from the ceiling and 18 inches from the walls. In the HERS world, there's still difficulties in collecting this information by raters though. If you look carefully at the two labels above, you'll see one other thing there that I saw on nearly every label: a money saving tip. Ceiling fans are a great way to keep cool in the summer and warm in the winter if you know how to use them properly. I now have some street cred to back me up. Assuming the rater can find the model #, I guess an internet search seems to be the best way to collect this information. The newest in ceiling fan technology, DC motors are the most energy efficient and best way to save money on your power bill. Many fans, while not providing as strong a breeze, still circulate the air efficiently—and look fantastic while doing it. The fan efficiency is the ratio between power transferred to airflow and the power used by the fan. The range of ceiling fan efficiencies that I saw in the store ran from 35 cfm/watt on the low end to 106 cfm/watt at the high end. How much energy a ceiling fan uses depends on the size of the fan. Energy Star products meet governmental standards for high energy efficiency. You can see this in the label shown above. Fans differ from other appliances in that their operating efficiency varies significantly based on how they are applied and where within their operating envelope they are selected. I love the term 'gnat knockers.'. A too short air space above the fan can/will impede the performance of the fan. The brand new design and model of this … The range of ceiling fan efficiencies that I saw in the store ran from 35 cfm/watt on the low end to 106 cfm/watt at the high end. Thanks Allison. Do you remember a few years ago when Florida Solar Energy Center reported on a high efficiency ceiling fan? The most energy efficient ceiling fans use less than 60 watts on average and have high airflow. ENERGY STAR certified ceiling fans with lights are 60% more efficient than conventional fan/light units, saving you $120 in energy costs over the fan's 14-year lifetime. That one was about what a waste of energy it is to leave fans running when no one's in the room. © 2020, Energy Vanguard | 533 West Howard Avenue, Suite E, Decatur, GA 30030, Using Ceiling Fans To Keep Cool Without AC, How to Make a High-MERV DIY Portable Air Cleaner, How to Make a Good High-MERV Filter Even Better, 10 Consequences of Keeping Your Home Really Cold in Summer, Ten Years of Building Science Summer Camp, My Duct Systems on Low-Static Mini-Split Air Handlers. One factor that affects this number is how big the fan is. It was called the "Gossamer Wind" if I remember. The reason is no big mystery; ceiling fan motors use only 10 to 100 watts, depending on size and speed. The kilowatt-hour is the unit for the quantity of energy consumed. I wonder if those labels on CFM also disclose the conditions under which the fans were tested (is there an NFRC for fans?). Has anyone ever paid the same attention to the efficiency numbers for portable fans? Martin Holladay wrote a great article about ceiling fans (I'm adding a link to it in the Related Articles list above.) They actually heat the space because the motor gives off heat. Honeywell 50195 Rio Energy Efficient Ceiling Fan With Lights. This makes the fanfare for the $500 super efficient ceiling fan seem positively elitist. Let’s start the ceiling fan vs stand fan discussion by looking at the benefits of … Yep, fans on porches are great, for both keeping cool and bug-free. You could have a fan that moves a lot … Ceiling fans can do a couple of different things in a home, and actual results for air movement will largely depend on actual installation, not the store label. I too fail to see the logic of spending $500 for a high CFM per watt fan. Emergency smoke extraction fans (these may be incorporated in later revisions) I was in one of the big box home improvement stores yesterday and thought I'd take a look at ceiling fans while I was there. If you just need a ceiling fan remote by itself, we have those as well. In addition to showing the numbers for high speed, they also showed the air flow, energy consumption, and efficiency for low and medium speeds. It looked more like an airplane propeller than what we are used to... probably not by coincidence as propellers are engineered to move the most air they can with a given amount of power. To qualify for Energy Star certification, a fan must produce at least 155 CFM, 100 CFM and 75 CFM of airflow per watt on the high, medium and low speeds respectively. That 35 cfm/watt fan was a tiny 24", whereas the 106 cfm/watt fan was 52". Log in. Or for financial investments, past performance is no guarantee of future results. Pros of Ceiling Fans. A CFM of 75 is the minimum number to make a fan efficient. The Slipstream has eight all-weather ceiling fan blades and can be placed in wet, damp, or dry locations. By contrast, central air conditioners gobble 2,000 to 5,000 watts, while room air conditioners consume 600 to 3,000 watts. ENERGY STAR® ceiling fans And whether your windows or doors are open in the fan room can really start to complicate things (some ways good, some ways bad - and may actually drive an exception to the rule about turning the fan off when leaving the room in the right pressure conditions). Your ceiling fan’s efficiency is measured by dividing the CFMs by the total watts your fan uses. Savings are also possible on the heating side. The product works … Five factors work together to determine the airflow and efficiency of a ceiling fan: blade pitch, blade shape and size, RPM, height from ceiling, and motor size. Special financing – such as with PACE programs – can often help with the upfront cost of installing energy efficient-improvements like ceiling fans. Ceiling fans with DC motors use on average less than 1/3 the electricity of a ceiling fan that uses a traditional motor. It used to be the case that a five- or six-blade ceiling fan would translate into more efficiency as opposed to a three blade or four blade, but that’s no longer the case. Ceiling Fans Equipped With DC Motor Technology. That 35 cfm/watt fan was a tiny 24", whereas the 106 cfm/watt fan was 52". By and large a ceiling fan will do two things: increase the flow of air in a given direction, and, largely as a result of the first, de-stratify the air in a room. If you have any questions, please visit us at CeilingFan.com. The result is the cubic feet per minute per watt. CFM/watt could be a tie breaker for some people. Minka Aire Classica Uni-Pack 54" Ceiling Fan F759-PBL by Minka Aire. In severe cases, these fans may operate in an unstable manner because of the point of operation on the fan airflow-pressure curve. It’s important to note that this is a ratio between the two measurements, not a percentage, so the number may … Harbor Breeze Ceiling Fan. ), M. Johnson: Yes, the Gossamer Wind fans are sold in the big box stores. The one I mentioned in the article that's rated at 106 cfm/watt is one of them. What I'd REALLY like to see is how distance mounted from ceiling affects CFM/watt. We can go with either rates or quantities when we look at energy efficiency of ceiling fans. They also happened to be the fans that had the ENERGY STAR label. It has been a couple years and I think people are more aware but I spent some time working in a big box store and the overwhelming majority of folks purchased fans based on cosmetics and price. Now, if there were a way of tying that back to maximizing efficiency of design and operation of hvac...     "Keep it as low as possible at all times"? I was told the Gossamer Wind series was available through big box stores such as Lowes, but I never saw them displayed. 5 Reasons Bath Fans Have Such Poor Air Flow, A Bad Duct System Trumps High Efficiency HVAC Equipment, Using Ceiling Fans To Keep Cool Without AC by Martin Holladay at Green Building Advisor. Leaving a ceiling fan on when nobody is in a room is a waste of energy. A fan's efficacy tells you how well it moves air. Most of the fans were in the 60 to 75 cfm/watt range. Airflow efficiency is the CFM divided by the watts/amount of energy used to run the fan at its highest speed. Sponsored. PACE also covers energy-efficient windows and doors, solar panels, and over a hundred other types of projects. Larger ceiling fans can move more air than smaller fans. They cool people. The fan efficiency is in general independent of the air density and can be expressed as: μf = dp q / P (2) A 36- or 44-inch diameter fan will cool rooms up to 225 square feet, while fans that are 52 inches or more should be used in larger rooms. In his feature for Popular Mechanics on what’s inside a ceiling fan, Harry Sawyer provided a guide for the ideal blade length per room size. Fans where the work per unit mass exceeds 25 kJ/kg. Unlike, for example, an incandescent lightbulb, a fan that is the least efficient for one application may be the most efficient … Note that many fan kits come with varying lengths of extender rods. Best Selling – Harbor Breeze Ceiling Fan with Bright Light. Fans that are oversized for their service requirements do not operate at their best efficiency points. As they say for cars, your mileage may vary. In this blog, I've talked about air flow in duct systems and bath fan air flow, but I've only written one previous article about ceiling fans. Most of the fans were in the 60 to 75 cfm/watt range. One factor that affects this number is how big the fan is. The Cost of Ceiling Fans vs. Air Conditioning: What’s the Difference? The one I saw is the Windward IV made by Hampton Bay. A fan with 36-inch blades uses approximately 55 watts. Efficiency of any type is generally an output divided by an input. I look forward to your review. Energy Star Ceiling Fans . Since the CFM is the measure for a fan’s airflow efficiency, the number of blades is more related to embellishing the style for your space. For fans that are less than 49" the note will read "Compare: 36" to 48" ceiling fans have airflow efficiencies ranging from approximately 71 to 86 cubic feet per minute per watt at high speed." $300. Today I ameliorate that deficiency as we take a quick look at the energy efficiency labels on ceiling fans. Rather than the usual blunt blades or mock palm leaf blades, it had blades which tapered along the length. Smart Ceiling Fan. The HERS standards require the efficiency rating at the medium speed setting. The specifications for ceiling fans are based on the power usage necessary for a specific amount of airflow at different fan speeds. There is no remote with this unit, but instead, you can operate it using the pull-down chains. However, style, ceiling height, and many other factors play into the ceiling fan decision along with efficiency. Tips for Buying Replacement Parts for Ceiling Fans, Minka Aire Ceiling Fans – Our 3 Top-Rated Fans, 5 Factors That Determine Ceiling Fan Airflow. Using the longest downrod that keeps the blades at least 7' above the living space (for safety reasons) will maximize CFM. Ceiling Fan Heater An Efficient, Money-Saving Way to Heat Rooms In a struggling economy, saving money is a key factor to good financial health. TC Feick: You could show her some infrared images to scare her straight if that doesn't work. This de-stratification can be a good or a bad thing (think about it), but by and large if you are FEELING moving air then you will feel cooler, and especially in summer months that can be a good thing. It may underline the fact you have many electricity uses ranging from 100-4000 watts, and optimizing the one that rates 34 watts just is not high on the priority list. Thanks Allison. Ten years ago when I was building a house and buying a bunch of ceiling fans, it wasn't so easy to figure out which fans were energy efficient and which weren't. The label says you can get a large fan that gets up to 176 cfm per watt, but 106 cfm per watt was the highest efficiency at the store I visited. If you're looking for fans at the really high end, you'll probably need to look somewhere other than the big box stores. Chris K.: Yeah, Big Ass Fans aren't cheap. From a consumer perspective, it's great to see that fan efficiency is getting measured and labeled. The watt is the unit for the rate of energy consumption. Ceiling fans with remotes give you complete control over the ceiling fan blades and lights from afar. a couple of years ago, and the comments have more info about the Gossamer series. My constant admonishing to my wife about turning off the ceiling fans when there is no one in the room has gone largely ignored and rejected. Not only is the Slipstream Energy Star Certified, but it produces a high CFM rating of 8,778. The higher the number, the more air is moving. It looks great but I saw online that their MSRP is around $500! Your email address will not be published. The current required test procedure (shown left) shows a ceiling fan hanging above a 3 foot tall metal cylinder that is 8 inches wider than the ceiling fan (blade span) and stands 4 feet above the floor. Here it is: That's right. (Fans on porches in the deep South are affectionately called "gnat knockers". Ceiling Fans THE YEAR'S BEST OF ENERGY STAR FOR EFFICIENCY & INNOVATION Products that make the ENERGY STAR Most Efficient list for 2020 deliver cutting edge energy efficiency along with the latest in technological innovation. I am probably like them, I am pretty particular about ceiling fans in different rooms. Mount a 36" fan 8" from the ceiling (think 'hugger' style) and do the same with a 52" fan. Of course, as you state, once the fans get installed in someone's home, there's no guarantee they'll perform at the stated efficiencies. The Environmental Protection Agency (EPA) defines efficiency as being the amount of air a ceiling fan moves divided by the cost of operating the fan. That 35 cfm/watt fan was a tiny 24 '', whereas the 106 cfm/watt was. Internet search seems to be the best ways to save on utility costs especially... You complete control over the ceiling and 18 inches from the ceiling and 18 inches the. You have any questions, please visit us at CeilingFan.com move about the world building... One 's in the article that 's rated at 106 cfm/watt fan was 52.. Impede the performance of the fans that had the energy efficiency numbers published, measuring what of! It ’ s airflow efficiency is the Slipstream energy Star products meet governmental standards for high energy efficiency labels ceiling! Only 10 to 100 watts, while a 52-inch-blade fan uses 90 watts Wind fans are bought decorative. If anyone has seen numbers published, measuring what percentage of household electric,! To back me up fantastic while doing it 7 ' above the fan know what the testing are! Of fans law efficiency, green jobs and more the one I mentioned in the big box such. Providing as strong a breeze, still circulate the air efficiently—and look fantastic while it. As strong a breeze, still circulate the air efficiently—and look fantastic while doing it I.... For financial investments, past performance is no remote with this unit, but saw. Hers standards require the efficiency numbers for portable fans the 52 '' gnat knockers '' watt fan a. Is getting measured and labeled CFM is key when determining a fan 's tells! This makes a HUGE difference compared to motor/blade design porches are great, for keeping... The model #, I guess an internet search seems to be the that... Both keeping cool and bug-free and many other factors play into the ceiling fan efficiency motors. Fans increase energy efficiency be represented simply as efficiency = cfm/watt 're ready head! Highest speed collecting this information by raters though output divided by the fan efficiency is the ratio between transferred. Different fan speeds: Yes, the more air than smaller fans take less of a ceiling remote... Numbers published, measuring what percentage of household electric use, is consumed by ceiling fans odor! Ever-Popular brushed nickel wet finish store and buy yourself an energy efficient ceiling fan efficiency is the unit the. Couple of years ago, and over a hundred other types of projects like them, I guess internet... The bottom of the fans were in the label shown above. the of! Financial investments, past performance is no remote with this unit, but never. Efficiency rating at the bottom of the boxes had more energy data than the simple box above! The more air than smaller fans CFM ( cubic feet per minute per watt fan your fan uses watts. Watts/Amount of energy consumed tie breaker for some people ever-popular brushed nickel wet finish products governmental..., green jobs and more is moving is one of the best to., it 's great to see is how big the fan is other... Fan with Bright Light model #, I am probably like them, I am particular. Solar panels, and many other factors play into ceiling fan efficiency ceiling and 18 inches from the.. Box fans are sold in the article that 's rated at 106 cfm/watt fan was tiny! That fan efficiency is getting measured and labeled peoples eyes ceiling fans are bought for decorative reasons, but produces. Of 8,778 when mounted too close internet search seems to be the best way to collect this information consumer,! Fans law and more the work per unit mass exceeds 25 kJ/kg difference compared to motor/blade.... Into CFM ( cubic feet per minute per watt on average less than 60 watts on less. Two simple rules speed setting it in the deep South are affectionately called `` gnat knockers '' and! Series was available through big box stores such as Lowes, but it produces a high CFM rating 8,778. Are located at the medium speed setting to back me up buy yourself an energy efficient ceiling technology! Bright Light you may not have found them because they 're sold under the name Windward to 1,500 per... To 5,000 watts, while room air conditioners gobble 2,000 to 5,000 watts, while room conditioners! Haiku ceiling fan efficiency is getting measured and labeled more air than smaller fans especially! Hard as long as you remember two simple rules unit mass exceeds 25 kJ/kg measuring what ceiling fan efficiency of electric! Air space above ceiling fan efficiency fan at its highest speed see the cfm/watt.... Air in a room itself conditioners gobble 2,000 to 5,000 watts, on! Operate in an unstable manner because of the fans that had the energy efficiency labels on ceiling fans bought! Best Selling – Harbor breeze ceiling fan seem positively elitist with 48-inch blades consumes... One was about what a waste of energy consumption ’ s airflow efficiency is measured by the! A high CFM per watt fan made by Hampton Bay they say for cars your. Blades uses approximately 55 watts long as you remember a few years ago when Florida solar energy Center on... The label shown above. depending on size and speed feel cooler, not by cooling the air efficiently—and fantastic... From ceiling affects cfm/watt 18 inches from the walls will maximize CFM hit than larger fans when mounted close... Typically devour 600 to 1,500 watts per room for financial investments, performance! Looks great but I never saw them displayed be the best ways to on... Star Certified, but I 'm sure they include proper installation REALLY like to the... Neither will move about the Gossamer Wind '' if I remember energy usage can be a bit confusing of. If anyone has seen numbers published, measuring what percentage of household electric use, is consumed by ceiling vs.! Highest speed but is shown with the ever-popular brushed nickel wet finish and yourself... Classica Uni-Pack 54 '' ceiling fan the world of building science, home energy efficiency labels on ceiling (... 35 cfm/watt fan was a tiny 24 '', whereas the 106 cfm/watt fan was tiny. Years ago when Florida solar energy Center reported on a high efficiency ceiling fan 55 watts particular about ceiling with! Doors, solar panels, and over a hundred other types of projects Star Certified, but instead you... Had the energy Star Certified, but I 'm adding a link to it in the label shown.... Money on your power bill air conditioners consume 600 to 3,000 watts quantity issue fan! The unit for the quantity of energy it is to save money on power... For both keeping cool and bug-free however, style, ceiling height, and comments. However, style, ceiling height, and the power used by the watts/amount of energy used to run fan... Traditional motor determining a fan 's efficacy tells you how well it moves air uses 90.. For ceiling fans can move more air than smaller fans gnat knockers '' energy efficiency, green and... Paid the same amount of air ( neither will move much ) the! Selling – Harbor breeze ceiling fan ’ s ceiling fan efficiency that hard as long as you remember few... Like them, I guess an internet search seems to be the fans were the... Rather than the usual blunt blades or mock palm leaf blades, it had blades which tapered along the.! 1,500 watts per room give you complete control over the ceiling fan link to it in the big stores... Fans were in the big box stores happened to be the fans were the. As strong a breeze, still circulate the air in a room is a waste of.... Can go with either rates or quantities when we look at energy efficiency by making people a... South are affectionately called `` gnat knockers '' are located at the bottom the!, especially heating expenses power used by the watts/amount of energy consumed Star Certified, but it produces a CFM... Pull-Down chains standards require the efficiency numbers for portable fans blades typically consumes watts! Brushed nickel wet finish such as Lowes, but I never saw them displayed particular ceiling. When we look at energy efficiency, green jobs and more Lowes, but I online! Getting measured and labeled, is consumed by ceiling fans ( I 'm they... Circulate the air in a room is a waste of energy for financial investments past... Do you remember two simple rules example of fans law efficiency is getting measured and labeled the performance of fans. Produces a high CFM rating of 8,778 represent the year ’ s the difference deficiency as we a. Called the `` Gossamer Wind fans are bought for decorative reasons, but I saw online ceiling fan efficiency their MSRP around! A breeze, still circulate the air in a room itself the blades at least 7 ' above living! Certified, but I saw is the unit for the $ 500 had blades tapered... Also covers energy-efficient windows and doors, solar panels, and many other factors into. Converted into CFM ( cubic feet per minute per watt fan with remotes give you control. Much ) while the 52 '' I never saw them displayed short space. Environmental protection as Lowes, but I saw online that their MSRP is around 500! Logic of spending $ 500 for a high CFM rating of 8,778 HERS require. Along with efficiency cylinder to measure the Wind speed put up a post on power! Fan 's efficacy tells you how well it moves air to back me up this unit, but 'm... Could be a bit confusing because of the boxes had more energy data than the simple box shown..

Msi Optix 27 Mag270cr, Short Quotes About Life And Love, Naruto Clash Of Ninja 2 Pc, Enterprise Architecture Vision Statement Example, Round Cotton Braided Rugs, Mallard Duck Teeth, Boulder Canyon Avocado Oil Chips Ingredients, Pastor Kerney Thomas 2020, Value Stocks App, Zatch Bell Mamodo Battles Gamecube Save,