Photo by Sean Gallagher.
It's the peak of summer. For most, that means it's time for peak energy consumption. But how much electricity, exactly, is your AC guzzling? And might there be a more voracious energy hog among your appliances? The DIY experts at Stack Exchange offer a few tips on hunting that hog down.
Question: My electrical bill is outrageous. I pay three times as much my next-door neighbor, and four or five times what my neighbor across the street pays. Of course, the bill is worst in the summer (I live in central TX), but I've had the air conditioner inspected, and while the house is right at the maximum capacity for our unit, the unit should still be able to take care of the load. That also doesn't explain why our winter bills are larger than the comparables.
How do I go about figuring out where my money is going?
Answer: Kill A Watt & Eliminate
For devices that plug into an electrical outlet, you can use Kill A Watt or an equivalent device to monitor how much electricity the appliance is using.
If that doesn't help you hunt down a clear culprit, go low-tech and look at your electric meter as you turn off circuits at the service panel one at a time. When you see a big change in speed at which the wheel is spinning (for older meters) or the digits are changing (newer meters), you've found your hog.
Also, it might be time for an energy audit.
Answer: Invest in an Ammeter
Open up your electrical panel and measure the draw on each circuit. This will show you which circuits are drawing the most.
An alternative method: As Mike Powell points out, you can clamp on to the main lines and turn off each breaker, noting how much the value drops as each breaker goes dark. (You will have to do this for each leg of the main).
Once you know which circuits are drawing the most power, you can start eliminating devices on that circuit until you find the largest consumers.
To figure out how much your devices cost to run, see these formulae:
Watts = Amps * Volts
Kilowatts = Watts/1000
Kilowatt-hours = kilowatts * Hours used
Cost = kilowatt-hours * cost per kilowatt-hour
Or Cost = (((Amps * Volts)/1000) * Hours Used) * Cost per Kilowatt
You could also do like I did and split an old extension cord (so you can clamp on to a single wire), then plug one end into the wall, and your device into the other end. Then you can measure the draw of just that device.
— Answered by Tester101
Answer: Home Energy Monitors
Depending upon how much time and money you want to invest, there are several home energy monitors on the market, some of which are DIY installs.
The Blueline Powercost Monitor is a definite DIY install (for the most common meter types). It is a little box which interfaces with the meter (even analog meters), and monitors the usage in real time. It integrates with Microsoft Hohm (now discontinued), and delivers real-time statistics, recent usage history, fancy graphs, etc.
The other big contender is the TED 5000. This device offers pretty much the same story (statistics, history, graphs, etc.). It is essentially an ammeter hooked up to the electric line coming in your house. Because of this, it is more accurate than the Blueline. The downside is that you have to open up the breaker box to install this (which may or may not be DIY for you).
Compared to the standalone ammeter (~$80), the TED 5000 is significantly more expensive (~$250). However, the usage statistics over time may help you to reduce your overall electric consumption once you have found and eliminated the main hog(s) in your house.
If you find your air conditioning is the culprit, check out how long it might taketo make your money back after buying a new, more energy efficient AC.
More reading: Engadget Review of the Blueline - with some comparisons to the TED5000.
— Answered by James Van Huis
Answer: One More Home Energy Monitor
Brultech offers a solution called the ECM-1240 Home Monitorthat will show you how much each circuit uses. You might need an electrician to install it. It works like the ammeter. tracks usage over time and can send live data to your iPhone.
— Answered by Joseph
Comment: Don't Forget
When conducting a one-time measurement of an appliance's energy consumption, you must take into account that appliance's duty cycle. For example, your heat pump may draw exactly the amount of current it's supposed to, but if it's running constantly instead of for 15 minutes per hour, that's 4x the expected energy usage.
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