Our new apartment has an electric fireplace with a fully simulated flickering flame. Ever since we moved in, I've been wondering how it works. One night I tried to take the cover off to investigate after a few glasses of wine, and decided to abandon the project for various reasons. Last night, I finally broke down and asked the Internet.
I found several websites selling electric fireplaces, and two websites purporting to answer the question of how an electric fireplace works. The first is www.electricfireplacesource.com, which answers the question thusly:
An Electric Fireplace requires no venting or installation, simulates a fire very realistically and simply needs to be plugged in. Electric fireplaces may either be inserts that can be used in an existing fireplace or free-standing units designed to look like wood stoves.
An electric fireplace gives the exact look of a wooden fireplace with its flickering flame. It is an ideal alternative to traditional fireplaces. If you live in an apartment, condo or a house that doesn't support a chimney, the electric fireplace is the right choice for you. Some styles can be fitted even on a wall, and all you have to do is plug it in and sit back and enjoy warm, cozy ambience.
Some electric fireplace models give you the advantage of a remote control and all model provide freedom from ash, matchsticks or wooden logs. You can take this portable fireplace with you when you move, and it's hassle-free so you don't have to suffer a hectic installation or wiring program. Since there are no toxic fumes, it leaves your home clear and pollution-free.
The amount of warmth generated by an electric fireplace varies among manufacturers and models, but normally around 4,500 to 5,500 BTUs of heat is generated from an average unit. However, electric fireplaces are not intended to replace a heat source. They are built to provide comfort and a focal design element in a room.They even blend with your house decor, as they are available in a variety of designs and styles.
You'll notice that this describes what an electric fireplace is, but provides absolutely no information as to how the fake flame is created. Boo, electricfireplacesource.com.
Next up was the FAQ section of www.calmexfireplaces.com, which includes this unhelpful exchange:
Q: The flame looks so real. How does it work?
A: Dimplex has developed a patented technology called ElectraFlametm which provides a realistic, wood-burning flame.
Little did Dimplex know that it had foisted its online vagueries at someone who is uncommonly familiar with the U.S. Patent and Trademark Office website! Some quick searching revealed a number of patents assigned to Dimplex, and in a few minutes I had figured out how the flame is created. Behold, U.S. Patent No. 6,385,881, "Synchronized flicker device"!
A device is provided for enhancing the realistic appearance of flames produced by a simulated fireplace (gas or electric) by providing additional ambient lighting effects in response to sensed light intensity within the fireplace. The device includes a photosensor, a control circuit, and display lighting. The photosensor senses the level of light intensity produced by a simulated flame source and changes its resistive value accordingly. The control circuit has circuit parameters which uses the resistive value of the photosensor to determine whether to apply operational power to the display lighting. The display lighting consists of at least one lamp positioned above the simulated fuel bed. When simulated fireplace is operational, the display lighting of the device produces a "flickering" effect that is synchronized with the changes in light intensity occurring within the fireplace. The resulting ambient lighting effect realistically mimics the changes in light intensity that normally occur above the flames of a real wood burning fireplace.
You lose this round, Dimplex!