Thursday, February 19, 2015
Not All LED’s are the Same (Addendum)
In the recent blog of September 10th, 2013, EMI and LEDs – Not all LEDs are the same!we described dirty electricity and examined several brands of CFLs and LEDs. This blog tests several more brands of LEDs to determine which produces the least amount of dirty electricity.
It has often been said in the dirty electricity circles that LED lighting produces less dirty electricity than CFL lighting. CFL lighting produces dirty electricity due to the fact that CFLs operate at high frequencies (typically between 10kHz to 40kHz) and need electronics to control the voltages and frequencies to make it operate. LEDs, it is commonly thought, produce less dirty electricity since LEDs use DC current and the electronics needed to convert the 60Hz down to DC current is less complicated.
Our previous blog showed that this is not always the case. Depending on the circuitry that a particular brand uses to convert AC to DC for the LED to operate, the amount of dirty electricity produced by an LED can be many times that of a typical CFL.
So which LEDs produce the least amount of dirty electricity?
In addition to the Ecosmart, Philips and CREE brands that were tested before, a couple more LED brands were put to the test. Using a Stetzer meter and a Greenwave EMI meter, the dirty electric values of several LED manufacturers were measured. Both meters were used since the methods of their quantification of dirty electricity is different. These CFLs and LEDs were all chosen with the luminosity of near 800 lumens (the equivalent of a 60W incandescent bulb).
Using the Greenwave EMI meter on the LEDs and correcting for background dirty electricity levels: Ecosmart and CREE measured much better than Philips, though Ecosmart still produced more than 100mV of dirty electricity. Sylvania and FEIT Electric were two more pricey LEDs that were added to the test. While the FEIT Electric did perform better than the Ecosmart, the Sylvania measured a bit worse. Overall the least amount of dirty electricity was still produced by the CREE brand LED. The CREE brand added only 17mV of dirty electricity to the electrical circuit.
Using the Stetzer meter for the same test and correcting to a background level of dirty electricity: Ecosmart, CREE, FEIT Electric and Sylvania all again measured much better than Philips. Using the Stetzer meter, both the FEIT Electric and the Sylvania produced less than the Ecosmart. The CREE brand LED still produced the least amount of dirty electricity of the brands tested. Using the Stetzer meter, the CREE brand LED produced 39 ‘Stetzers’ of dirty electricity. [Please note: we do not know the precise definition as to what a ‘Stetzer’ equates to. The Stetzer Electric company has not openly defined it for others in the industry to understand and, therefore, is a questionable ill-defined unit. However, it does allow for comparisons to be made between brands for this limited study.]
What do these measurements say to us? On average, LEDs do produce less dirty electricity than CFLs, but be wary of the brand you are using! If you are sensitive to dirty electricity or are concerned about dirty electricity, Philips brand LEDs should be avoided.
In this addendum research we explored LEDs from Ecosmart, Philips, Sylvania, FEIT Electric and CREE which were all available from Home Depot. If dirty electricity is a health concern in your home and you are interested in saving electricity and money in the long run, it is most recommended that you consider using CREE LEDs based on this limited research. If CREE LEDs are not available, you might consider using FEIT Electric or Ecosmart. Sylvania LEDs were are par with Ecosmart, however the Sylvania LED was the most expensive of the LEDs tested ($37 per bulb!). Further research with different manufactures will be performed in the future to continually expand the selection of recommended brands. A direct link to Home Depot’s CREE LED webpage can be found here.