Customer Reviews

P3 International P4400 Kill A Watt Electricity Usage Monitor

5 star:		(447)
4 star:		(213)
3 star:		(53)
2 star:		(16)
1 star:		(28)

 

 

I absolutely love this thing.

Having recently moved out on my own, and generally just enjoying statistics in general, I bought this to monitor my electric costs after two high electric bills in a row. The various results I found were quite surprising.

My air purifier, which I bought here on Amazon, uses 85 watts all the time... 85 * 24 hrs * 30 days / 1000 watts = 61.2kWhr * $0.20 = $12.24 a month.

Well, that's quite a costly monthly addition I never thought of. And that's just the begining.

My Vornado fan uses 45w... my air conditioner, on high 6 (out of 12) spikes up to 1200 watts. Jeez.

My computer, at idle with external drives, uses about 250w. When doing extremely intensive things, like encoding a video, 310w.

My light behind my computer desk, with five, 10-watt bulbs, doesn't actually use 50-watts total. No, it uses 50-watts for the bulbs, PLUS 30-watts apparently just for the light unit to function.

You too will find out all these things you never knew, and possibly save money by cutting out, or replacing energy guzzlers.

The product is also made in China. Just like everything else now.

I absolutely love this product, it's one of the best devices I've aquired in a long time. When I purchased it a few years ago, I paid close to $50, but it was worth every penny. Some of my joy from using the device simply comes from the fact that I'm curious how much energy the products in my home use (I now know, for instance, that my cable box uses 15W of energy whether it is on or off, at that it wastes a little more than 10 kilowatt hours each month, or that my fridge uses 350W when on, or that my laptop only uses 40W - a useful fact to know when I went to buy an inverter to use it in my car), but it can also be used to save energy (I found that hitting the switch on the surge supressors of my computers at night can save me almost $5 a month off my electric bill). Additionally, it's interesting to find out where all the power you use goes, and even what members of the family use the most electricity (you could do a side by side comparason of a child's computer with yours).

Even though I've had my Kill-A-Watt for years, I still take it out regularly to test any new equipment in my home. I know my cell phone charger uses 4 W, my regular battery charger 5 W, and my IC3 15 minute battery charger 73 W.

Surely most will not have as much fun with this unit as I do, but it can be both practical and enjoyable for people such as myself or those looking to save some money off their electric bill. It's also an asset for anyone off-grid, who is generating their power with solar energy or by other renewable means.

Two years ago, my electricity consumption jumped about 40% and I ignored the problem until this fall's rate increases. I wanted to find out what I bought back in 2003 that's still eating power today. Enter the P4400 Kill-A-Watt unit, which is the only low-cost product of its type on the market today. I tried but failed to find its specifications online. So I bought a couple of these things to try them out. Here are the details on what it can do.

* How big is the display: 4 digits.
* What are the front-panel button capabilities: volts, amps, watts, volt-amps, power-factor, frequency (hz), KWH, timer (since reset).
* Does it lose its data in a power failure: yes.
* You have to plug the unit into a nonswitched wall outlet, it can't measure overhead lighting or large appliances.
* It will report the amount of time (hours:min up to 99:59, then hours for about a year) since last reset but won't tell you how much of that time the attached device was powered on.

How did I figure out usage? I created an Excel spreadsheet with the following columns: Device, estimated wattage, estimated hours/month, kilowatts avg/month, measured kwh/day, measured kilowatts, annual cost. I went through the house and inventoried everything I could find, entering it into a row of the spreadsheet. Then I filled in the estimates:

- Hours/month: if I use a TV 3 hours a day, I enter the formula 3*365/12; if I use a treadmill 45 minutes on 10 days a month, the formula is 0.45*10*365/12.
- Kilowatts (average over the month): formula is watts*hours/(24*365/12)/1000. If you have a 60-watt light left on 24/7, you should see the value 0.060; if you have it on a 12-hour timer, you should see the value 0.030.
- Annual cost: formula is kilowatts*365*24*cost. Locally the cost is 13.5 cents so a 100-watt device works out to $118.26 per year.

OK once I have that chart I then plug in the Kill-A-Watt to measure the items that might be chewing up more power than my estimates. For a device that you leave on all the time and which uses a steady number of watts, you can simply measure it for a moment and enter the kwh/day figure into your spreadsheet quickly. For devices like refrigerators or computer monitors or TV sets, you will want to leave the unit plugged in anywhere from a day to a week before entering your kwh/day figure.

The first thing that leaped out at me was how much it costs to run those econo-box desktop PCs. Sure enough, the culprit turned out to be those hot AMD and Intel processors: the tech industry wants you to focus on gigahertz and other performance numbers; they'll never tell you how many watts the computer will draw--because no one asks, not even Consumer Reports. A modern desktop easily draws 100 watts: refer to my earlier figure to see how much that costs, a dollar amount bound to go up in the future. Laptops would save power (though not necessarily enough to make up for the purchase price). Turning off the PC when not in use would save money, but at the cost of productivity: if you value your time, you don't like waiting 2 minutes every time you want to check an email (add those 2 minutes up over the course of a year!)

Bottom line: the Kill-A-Watt device will focus your attention on some of the devices that are costing you unnecessary money, and will definitely change the questions you will be asking as you purchase future household devices. I'd like to see a more feature-laden version, but not if it makes the Kill-A-Watt cost much more than the $25 I paid.

This is a nice little meter. It measures Volts, Amps, PowerFactor, Watts, VA, KWH and Elapsed Time in use. I got it to survey my house loads for a potential solar system and it performed very well. I could plug a device in to it for a week and figure out what the average power consumption was. I couldn't believe how bad the power factor is on my window swamp cooler.

The addition of a pigtail would be nice because it is hard to see behind furniture and it is so big that it uses an entire outlet while in use. A 240V mode would be nice also.

It worked better then I had expected.

If you are a "Miser," this device will be your best friend. I bought the "Kill-A-Watt" because I suspected that our old Fridge was shooting up the electric bill. I plugged the Fridge into the meter and left it for 3 days. I was very surprised to find out the the fridge was only burning about 1.5 KWH (Kilowatt Hours) per day, which is about what it should.

Now I am going around the house and plugging other appliances in for a couple days. The real shocker was that my "economical" eMachines PC along with a CRT monitor was using more energy than the fridge! The computer was burning almost 2 KWH per day. I made changes to the energy saver software in Windows, so that the monitor automatically shuts off in 10 minutes and the computer hibernates in 1 hour. This has brought the daily consumption down to 1 KWH.

For those of you who don't understand KWH, its a measurement of electric usage by the power company. To be simple, using a KWH is about .08¢ in our area. So, if you save 1 KWH per day, you save .08¢ After a month's time, it's about $2.48. After a year it's about $30 bucks. The savings add up over time.

With the Kill-A-Watt, I've found out lots of interesting things:

My Mac Mini with a LCD monitor uses about 1/2 the power of my eMachines Tower with CRT. That's 70 Watts vs. 140 Watts.

My Electric Blanket which I though was "economical" pulls 120 Watts during operation. It actually uses 1 KWH per day. I even found out that the blanket burns 10 Watts when the power switch is off!

I found many "power bandits" in my home. These are devices like cellphones, scanners, routers, modems that have those little black power blocks. Most of these devices use 5 to 10 watts with the power switch off. With the Kill-A-Watt, I was able to find the biggest offenders and plug them into a timer that shuts off each night when they are not in use.

If you are truly obsessive about your electrical bill like me, you can make a nice Excel spreadsheet with all your appliances. You can enter Watts, Kilowatt Hours, Price per hour and than figure if replacing a device would pay for the purchase and how long it will take.

As everyone says in their reviews, "This device will pay for it's self."

I bought 4 of these altogether, and found them very useful for measuring electrical loads. However, 2 of them have failed -- the LCD display goes blank. Fortunately, the device is passive, so that attached appliances continue to run, but the information is lost. One of my failed P4400s was returned to Amazon for credit, but another one failed after Amazon's 30-day limit on returns. I wrote P3 International, but they never responded. Although I love the device, any manufacturer who doesn't respond to a customer inquiry like this gets an automatic 0 stars (1 in Amazon's system).

Update -- all 4 have now failed with the same symptoms.

This piece of test equipment has just saved me hundreds of dollars by avoiding our purchase of a new freezer. While our chest type freezer is over 25 years old my wife and I suspected that it was the cause of our high electric bills. However after monitoring it for a number of days with this meter we discovered that the power it was taking to run it was very nominal and there would be no payback for at least 10 years to replace it with a new one.

I bought this and figured out my 25 year old refrigerator was using over $50.00 a month on electricity. I went out and bought a new refrigerator that only uses $15.00 a month. Now I am saving $420.00 a year on electricity. THIS IS A MUST HAVE DEVICE.

I have had one of these for 3 months and it has worked very well. I started by testing 60W and 30W bulbs and the meter gives me a dead on accurate wattage reading so I assume that the wattage that it reads for my fridge and other items is accurate.
I next started to use the unit to gather data on how much power my home devices where using and locating which items where power hogs, one great surprise was that my Ceiling fans use about 1/3 the power of my Bedroom AC units! If most people realized that the power consumption was that high they would probably not install them. After testing I decided that the cooling effect VS $$ it was a better value to go back to using my AC.
For people who are using Solar Energy or RV owners this gadget is very handing for mapping out your power use, just keep in mind that it only reads 110/120 volt devices

Plug it in and then plug in your device and it'll tell you how many watts it's using. Leave it plugged in and it'll tell you how many Killowatt hours you spend on that device, on average. This is useful for finding out how much your computer is using, for example. I found that my main computer varies from about 100 watts to 250 watts depending on what I'm doing. I also noticed that even when it's turned off it uses 15 watts of power.
If I could find any negatives it's: 1) can't do 220 Volt outlets 2) can't download the information to a computer. 3) have to turn off the device to plug it in. i.e. I have to turn off my computer, plug it in to Kill-a-watt and then plug that into the wall.
But I knew these things before hand.