How to Choose Energy Efficient Ceiling Fans

When looking for a ceiling fan, most homeowners tend to use them on moderately warm days instead of using their air conditioning, but choosing an energy efficient ceiling fan can be a daunting task. There are literally hundreds of ceiling fan models to choose from, but there are three lines from three different manufacturers each with special ECM motors that outperform standard ceiling fans.

In addition to an energy efficient ceiling fan, you can buy lighting kits that can improve your old fan and upgrade its energy efficiency. Instead of purchasing new fans you can retrofit your old ones. However, if you want to change the look of your home and overall comfort, invest in energy efficient fans with the Energy Star label for the most energy efficiency.

Energy Star Rating

Energy Star-qualified residential ceiling fans undergo testing to determine airflow efficiency based on cubic feet per minute (CFM) airflow per watt of energy consumed.

These measurements are taken at low, medium, and high speeds and given a score at each speed. At low speeds, Energy Star's minimum airflow requirement is 1250 CFM with an efficiency of 155 CFM/watt. At high speed the requirement is 5000 CFM and 75 CFM per watt.

Energy Star claims its fans are 50% more efficient than non-qualified models.

A PDF of Energy Star rated ceiling fans can be found at http://www.energystar.gov/index.cfm?fuseaction=find_a_product.showProductGroup&pgw_code=CF  There are Excel spreadsheets and PDF formats and the database is broken down in to Qualified Ceiling Fans, Qualified Ceiling Fan Light Kits, and Qualified Ceiling Fans with Light Kits.

What are EC motors?

Newer ceiling fans are extremely efficient because of they use electronically commutated motors (ECM), also known as DC brushless motors or sometimes called EC motors. ECMs have electronic commutators which is part of the motor that helps control motor speed and torque rather than mechanical commutators and brushes, and use permanent magnet rotors and built-in inverters.

ECMs can be precisely controlled to maximize efficiency as the motor changes speeds, and there are almost no mechanical losses or heat generation that you find in AC motors. This is why they are far superior motors for low horsepower uses like a ceiling fan.

Fan Blade Selection

Manufacturers claim that newer airfoil fan blades are more efficient. This is true at high speeds, but at lower speeds the fans may actually be less efficient than standard fan blades. The number of blades, the size, and the pitch also affect energy consumption. If the motor is not correctly sized for the fan blades the performance drops off significantly. Before EC motors came into use, the blade was an important factor relating to energy efficiency.

Ceiling Fan Selection

Ceiling fan blade spans range from 29 – 54 inches - the most popular being the 52-inch model. To determine which size you need, measure the room where the ceiling fan will be installed and follow these guidelines:

Ceiling fans should be installed, or mounted, in the middle of the room and at least 7 feet above the floor and 18 inches from the walls. If ceiling height allows, install the fan 8 - 9 feet above the floor for optimal airflow.

Wet/Damp Rating. If you are placing a ceiling fan in a bathroom or other humid locations you will need to purchase a fan that has been UL listed with a “damp” rating. For fans that may come in direct contact with water, like on a patio or front porch, look for a UL “wet” rating. These fans include features such as sealed/moisture resistant motors, rust resistant housing, stainless steel hardware, and all weather blades.

Light Kits

If you are replacing an existing light fixture with a combination ceiling fan and light kit you may want to install an energy efficient light kit equipped with a CFL lighting kit. Some of the top rated fans are equipped with an integrated CFL light kit.

Most Efficient Fan

The Emerson Midway ECO is the first of a new breed of ceiling fans that sets the standard for the future. Proven to be over 300% more efficient than any other Energy Star qualified ceiling fan with lights. The Midway Eco, model CF955WW is a powerful, yet low energy consuming fan that moves 6,936 Cubic Feet of Air per Minute while consuming only 24 watts of electricity. This is an unprecedented breakthrough in ceiling fan technology and far exceeds the standards set for Energy Star Qualification by the Department of Energy (DOE). The light fixture uses 4-13 Watt CFL bulbs for the equivalent of about 200 Watts of incandescent light while only consuming 52 Watts.

The fan and lights combined use about as much electricity as a 75 watt light bulb.

The fan comes in three colors, rubbed bronze, brushed steel, and gloss white.

Emerson Midway ECO Ceiling Fan Model CF955WW

The only downside is that the fluorescent light fixture is not dimmable. The prices ranges from $400 to $750 depending on size, finish, and options.

This fan is so efficient that if you operated it for 12 hours a day, 365 day a year your annual electric cost would be $12.61 at $0.12 per kWh. This is because the fan only uses 24W per hour while the average ceiling fan uses about 76W per hour.

Other very efficient models are Emerson Avant ECO (DC Motor) Ceiling Fan Model CF921BS and Emerson Carrera Grande Eco 60 (DC Motor) Ceiling Fan Model CF788ORB.