Home > Is Your Light Bulb Making Your A/C Work Overtime? Is Your Light Bulb Making Your A/C Work Overtime? Your forehead is drenched in sweat. The ice cubes melt before you even get to put them in the glass. The AC is cranking away full-blast, but you’re getting no mercy. Yes, it’s summer time. A time for fun, vacation, family picnics…and temperatures that make you wish the sun would just die already. Sometimes there’s nothing much you can do about it but sweat and smile. But have you ever thought about how much heat your light bulbs gives off? It is well-known that incandescent light bulbs use more energy than alternative light bulbs such as fluorescent and LED lights, and therefore force you to pay more in energy costs every month. But what is not mentioned so often is how much heat incandescent light bulbs give off. The more watts in an incandescent light bulb, the more heat fills up your home. And the more heat from light bulbs in your home, the more you’re living like a lizard basking under a heat lamp without even knowing about it. Approximately 95% of the energy required to illuminate an incandescent light bulb is emitted as heat. That leaves only 5% that makes the light you’re using the bulb for! All this heat goes into your home and increases the overall temperature, making you hotter and making your A/C work harder. The reason for all this extra heat is because incandescent light bulbs use heat to make light. The light you see in an incandescent light bulb is produced by heating up the filament inside until it is white-hot, thus producing the white light that you see. Thus, the light you see is actually heat. It is estimated that the average temperature in a home can be raised approximately 5 degrees from the use of heat-produced light from incandescent bulbs. So next time you break into a sweat while reading a book, it might not be from the gripping suspense – it might just be your reading light! Thus, if the fact that governments all around the world are starting to ban incandescent light bulbs due to their energy inefficiency wasn’t enough to convince you to switch to fluorescent bulbs, then maybe the profuse sweating and ice bulbs melting before they get to your glass will!