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Usage Monitor

Put a Kill A Watt P3 to Work for You: How to Use a Kill A Watt P4400 Power Usage Monitor

The Kill A Watt P3 series is the "standard" home kilowatt hour meter. Just plug it into the wall, plug an appliance or lamp into it, then leave it alone for a few days. It will automatically total up the watt-hours used and the hours it's been plugged in. It provides important information that helps you lower electricity bills in the most cost-effective way.

Measuring Loads

You'll normally want to let Kill A Watt and the load run for a few days so that you get average readings. You should write down the readings at about the same time as you plugged everything in so that you're capturing full daily usage patterns.

So after a couple of days press the KWH/Hour button and write down the total kilowatt hours consumed. Press the KWH/Hour button again and note the hours of the "recording." Dividing kWh by Hours gives you the average kilowatt hour draw, per hour. Multiply by 24 hours and you have exactly the total kilowatt hour load per day. Multiply this by your utility's rate per kWh and you have the daily energy cost for that load. From there it's easy to get monthly and yearly costs.

Small Loads

Some appliances, such as digital clocks, draw only a few watts. Due to the display resolution you'll need to accumulate data for a couple of hundred hours to get an accurate read out. This kind of accuracy isn't too important for a home energy budget, but it can be important if you're planning for a solar-powered remote cabin. The Kill A Watt P3 has sufficient accuracy and resolution to measure these small loads.

Phantom Loads

Many appliances are energy vampires. They draw standby loads even when they're turned off. It's easy to find an energy vampire – the killawatt will show a wattage (and volt-amp and amp) draw even when the appliance is turned "off." You can take the wattage display and multiply by 24 hours to see how many watt hours are used each day. It's not uncommon for a single phantom load to be ½ kilowatt hour per day. That's only about 5 cents a day but over a year that adds up to $18. Entertainment centers and personal computers are notorious vampires. It's not at all uncommon for all phantom loads and always-on items like cordless phones to use over $100 worth of electricity per year and represent as much as 20% of your total electricity use. You can slay most vampires by simply unplugging them or putting them on a timer. And each incandescent bulb your replace with a CFL will save $5-$10 per year. So you see how it can be relatively easy to cut your bills by 10% without replacing any major appliances.

Home Energy Assessment

A kilowatt hour meter like the Kill A Watt P3 should be a part of any home energy audit. Looking up typical appliance wattage from a table and estimating usage hours can lead to missing both big savings opportunities and small easy-to-fix losses. It's important to know what your old appliance is using when considering replacing it. And standby phantom power can vary tremendously between different brands and even different models. Here's a priority list of electric loads to check out.

Refrigerators – usually the largest electricity user after central air conditioning. Although it's name-plate power rating may not seem that much worse than new energy-efficient units, less insulation and age-related problems can cause it to run many more hours.

Window air conditioners – Like refrigerators, inefficiencies may show up in the hours it needs to run and actual (versus name-plate and typical) watts used.

Lamps – Lighting is another big energy user. You may be surprised how long, or how little, a particular light is used. Or just how many watts a particular lamp uses.

Personal computers and peripherals – There's a lot of variation between regular load and especially standby load for different brands and models.

Fans and portable heaters.

Stereos – some models with remote controls have surprisingly high standby loads.

Video games – there are huge differences in both standby power and turned-on power between the leading consoles.

Washing machines and dryers – even gas-fired dryers can be a significant electricity draw.

Microwaves and toaster ovens – Another appliance with lots of variations between manufacturers and models. For an infrequently used appliance, standby power may be greater than the power of actual use!

The Bottom Line

With a list of all your electricity users, it's easy to find the biggest loads. You can focus on those and decide where you'd benefit from an appliance replacement. In other cases a simple timer or motion-sensor may be a quick and easy path to save on electricity bills. Sometimes lower electric bills are as simple as turning off the lights and TV when you leave the room. Knowing exactly how much it's costing you can be a great motivator. Knowing your electricity users, you can easily save 5%, 10%, sometimes even 30% off your electricity bill. That can be hundreds of dollars each year. Not bad for a $25 Kill A Watt P3 kilowatt hour meter.

About the Author

You can find out about the various Kill A Watt models, and purchase them here.

 

JD Roberts has over 10 years experience as an energy professional.  His projects have ranged from his own home to managing the auditing of millions of square feet of commercial buildings.  He has also been involved in the design of energy-efficient homes and commercial solar energy systems.

Belkin Conserve Insight Energy Use Monitor