You've seen the ads - "Amish made space heaters cut your utility bills by 50%" or similar claims. There are also a series of ads for heaters that look like a big wood box, claiming their safety and energy efficiency. Every month, I get questions about these devices from people looking to save money on their utility bills. What's the real answer?

The first, and most important thing to know is that ALL electric space heaters, from the $29.99 device from your hardware store to the $399.95 miracle heater are essentially 100% efficient at converting electricity into heat. They work on the same principle as a toaster - electricity passes through a heating element and heats up then a fan blows the air around the room. 

The way these devices differ is their air distribution. some don't use fans, relying on convection. For example, if you have electric baseboard heating in your home, these work this way. Others are small metal cabinets that have glowing metal elements and a noisy fan to blow air around the room. Others are shaped like radiators and are filled with oil. 

All of these devices work at getting heat into the room. In fact, I've used the oil-filled radiators and like them quite a bit for heating rooms in emergencies. These particular devices have no exposed super-hot element. Instead they have the radiator fins, which get hot, but not enough to start a fire. The heat is dispersed naturally through convection, so they operate silently, other than a periodic gurgle. 

What you need to know however, is that all of these electric space heaters produce the same amount of heat for a given amount of electricity. This $50 electric radiator is just as efficient as a $350 electric miracle heater. But here's the kicker - in most areas of the country, pure electric heat costs two to five times as much as most other conventional sources of heat, such as natural gas and heating oil.

This is a critical factor. If you're looking to save money by running a few of these devices around your home instead of running the furnace, you're in for an ugly surprise as your electric bills shoot through the roof! The only way you might save energy is if you turned off your central heating system and closed all the doors to the rooms in your house. Then, you put one of these heaters in one room with you. You would be warm in that one room and freezing in the rest of the house. That might save some on your heating bill.

Note that these devices are not to be confused with heat pumps. Heat pumps actually work to give you several times the amount of heat out for a given amount of electricity in. So, the Fujitsu 12RLS that I reviewed elsewhere, actually is very efficient and cost effective to run. However, even that, at current energy prices (Fall 2009) does not have as low an operating cost as natural gas. 

Just remember, when you see ads claiming some sort of "energy efficiency breakthrough", in all likelihood, they're taking advantage of people's fear of high energy costs. Basic physics dictates how efficiently heaters operate, and no new physics has been discovered.

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Power Factor correction devices are popping up everywhere. Costing from a couple hundred to thousands of dollars, manufacturers claim that they'll save you 10%-20% off of your electric bill. What they don't tell you is that there are virtually no electric companies that will actually reduce your rates based on the power factor of your home!

Don't get me wrong, from an engineering perspective, power factor is important. In fact, I installed an industrial device that does voltage "smoothing" and power factor correction on my own electrical panel because it helps to improve my home's power and provides whole home surge supression. But it does not lower my electric bills!

Power Factor (PF) is a measure of how well the electrical load matches up with the voltage on the power line. Without getting too technical, there are different types of electrical loads. One, like a toaster,  or filament light bulb, is called a resistive load. All of the energy used by the device matches the changing voltage on the power line. Others, like electric motors, are called inductive loads. Your air conditioner or refrigerator are typically inductive loads. In an inductive load, the energy used by the device does not match the changing voltages. The Power Factor is a measurement of this mismatch between energy used and voltage. (Engineers please forgive the imprecise description. I'm trying to keep this simple.)

The reason that the PF is important is that the electric company still has to deliver the total energy to supply your needs, regardless of the PF. However, homeowners are not charged differently based on the PF of the devices in the home. Because of this, installing a PF correction device DOES NOT reduce your utility bills. 

There's a lot of mis-information out there about these devices, and the companies that make them are marketing them hard to resellers. Most of the resellers believe that these devices work. And they do work to correct the power factor of your home.They just don't reduce your electric bills.

Eventually, the utility companies may charge depending upon the power factor of your devices, but for now, save your money and stay away from these devices!

Note for businesses: 

Many businesses are charged for the power factor of their devices and in these cases, PF correction can reduce your charges 10%-20%. If you have a business that uses lots of machinery, you may be a good candidate for PF correction. However, first consult your electric company and discuss your situation with them. They will tell you whether you can save money through PF correction.

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