question on pellet stove and electric usage

[iceman]

i was looking at the harman accentra insert and it uses 350 watts?? if that thing is running constantly isn't that alot at the end of the month?
if you have an insert please post how much your elec bill goes up a month in the winter
thanks

 

[GVA]

I think that is startup wattage only Probably should be around 250 watts in normal operation....
It might be tough to tell how much someones bill goes up due to the stove, because it gets dark earlier, people spend more time inside, which means more overall power usage etc.

 

[stoveguy2esw]

not really , if you look at the cost compared to the watts used for electric heat , pellet stove in my home replacing a woodstove as primary heat source did not raise my electric bill noticably. i figure its like leaving a few lights on in comparison (maybe 3 hundred watt bulbs and a 50 watt bulb).

 

[moralleper]

i figured this last year by hooking up a Kila-Watt to my stove for 1 month. the total cost of electrity was somewhere in the neighborhood of $2-$5 extra. I have a Quad santa fe which is regulated with a thermostat so it is only on when it is needed. That and our electricity is pretty cheap out here in my neck of the woods. the last bill said 5.3 cents per kw.

 

[Highbeam]

I just bought a kill-a-watt last weekend and have been getting a big kick out of it. My two TV setups use 14 and 8 watts while turned off! The refer is where I am going to set up the killawatt for a long term data collector. I think it is a sucker.

Oh I got it at Harbor Freight for little money. It only handles 15 amps and tells me volts, and frequency of the power source too.

 

[drizler]

My electric bill went way down when I went to the stove. That big ass motor on the oil burner that sometimes dims the lights a tad when it kicks on sucks juice like crazy. One thing that will save you bucks is the new small compact flourescent lights. I just got a big multipack at Sams club to replace one of the bar lights that burned out in my fish tank. Wow those little 40 watt bulbs do toss the light. Big improvement over even the ones from a couple years ago. 6 bulbs for $12, not bad at all.

 

[oregonrider]

My electric bill runs about $50 a month in the summer and about $ 60 a month in the winter so I don't think my pellet stove draws that much juice. roben.

 

[Corey]

Running 250W/hr for 24hr/day 7days a week would add 180 kWh to your monthly electric bill. If you are paying $.06/kWh, that is about $11, of course $.10/kWh would be $18, etc. One thing to remember, is that you are getting back most of that electricity as heat - in one form or another (warm motors, warm electronics, transformers, etc) so it may not be quite as bad as it sounds.

To look at it another way, assuming 8000btu/lb pellets, burnt at 80% efficiency = 6400 btu/lb delivered to the living space. Then 250 watts/h ~850 btu/h. So the electricity is saving you 850/6400 lbs worth of pellets - or about 0.1 lb of pellets per hour, or about 72 pounds per month - running continuously. So you'd really have to plug in your electricity rate and what you pay for pellets, but at first glance, they offset fairly evenly.

Corey

 

[karl]

350 watts is about 3 amps. These people with the kilowatt meters will tell you the average house pulls close to 10 amps with everything turned off. Unplug all of your wall transformers when you arent using whatever they are hooked to. That will off set the 3amps from the blower.

 

[Highbeam]

"These people with the kilowatt meters will tell you the average house pulls close to 10 amps with everything turned off."

I disagree. 10 amps is over 1000 watts. The sum of my phantom loads is less than one amp. Even the little transformers that do warm up were pulling less than a watt so I left them plugged in. I ran my "Mr. Coffee" this morning for my usual 12 cup pot and the entire brew cycle plus one hour of keeping it hot was less than 0.25 KwH or about 3 cents. It pulles about 1000 watts when the element was turned on.

 

[karl]

highbeam that confuses me. Those little transformers should be pulling almost their entire rating even when not in use. Atleast, that's what the conservation people say. I know my 90 watt laptop transformer is just as warm with it unhooked from my laptop as it is when it's hooked up to it. I have also read other places that they pull 1 to 5 watts when not is use. Maybe it depends on the transformer or maybe it's alarmist propoganda.

 

[thechimneysweep]

According to the US Dept. of Energy article at http://www.eere.energy.gov/consumer/your_home/space_heating_cooling/index.cfm/mytopic=12570, the average pellet stove uses an average of $9.00/mo of electricity. This article has been up for a few years, so Cozy Heat's estimate of $11 seems right on the money.

 

[Highbeam]

highbeam that confuses me. Those little transformers should be pulling almost their entire rating even when not in use. Atleast, that's what the conservation people say. I know my 90 watt laptop transformer is just as warm with it unhooked from my laptop as it is when it's hooked up to it. I have also read other places that they pull 1 to 5 watts when not is use. Maybe it depends on the transformer or maybe it's alarmist propoganda.

The reason I checked the transformer draws was because I was always going around unplugging them and it got the wife pretty bothered. I wanted to show her the cost of having them plugged in all the time. I checked two different ones, the one for a baby monitor and the one for a cordless razor charger and they both popped up with zero watts. Now these are small appliances and relatively new so maybe the phantom loads are somehow related to the output of the appliance. I was able to conclude that the transormers aren't really all that bad. The razor charger passed three watts while charging my razor so I know that the killawatt will read that low.

I still haven't put the killawatt on my computer room powerstrip which has all sorts of potential phantom loads.

 

[mkmh]

I have a kill-a-watt meter coming in this week, so I look forward to checking my 2 pellet stoves to get a precise read. My perception is in line with what others have stated here. Each stove adds 7-15 bucks per month (electric is fairly expensive here) to my bill. My installer cautioned me about using a programmable thermostat in such a way that it caused the stove to cycle on and off several times a day. It makes sense that "invoking" electric igniter more than once or twice per day could drive up the usage quite a bit more.
I'll try to come back in here and post my findings for the St Croix and the Harman P61, once I have some "hard" data (It has to cool off first, though)

 

[jtp10181]

Thanks for talking about the Kill-A-Watt. I just ordered one from NewEgg for $20, http://www.newegg.com/Product/Product.aspx?Item=N82E16882715001

Can't want to try it out on the power strip this thing is plugged into. Then my wifes. Then the Cable Box and TV! My electric bill in the summer is over $100 a month. I want to see whats costing so much.

 

[Corey]

highbeam that confuses me. Those little transformers should be pulling almost their entire rating even when not in use. Atleast, that's what the conservation people say. I know my 90 watt laptop transformer is just as warm with it unhooked from my laptop as it is when it's hooked up to it. I have also read other places that they pull 1 to 5 watts when not is use. Maybe it depends on the transformer or maybe it's alarmist propoganda.

I think there may be some linguistics at play here. The enviro-nazi crowd would probably claim something like "power supplies waste as much energy when not in use as they do when fully loaded" The key here is that a good switch mode power supply (SMPS) wastes very little energy either way. They can 'theoretically' be 100 percent efficient, but in practical use are generally ~95% or so. To put it in round numbers, the 100W SMPS which is plugged into the wall, but no load may draw 5 watts just setting there, and get a little warm to the touch. But when you plug it into a 95 watt load, it still only drawing 100 watts total. The basic inefficiency is the internal resistance of the electronic components - capacitors, inductors, transistors, etc that make up the supply. This doesn't change as load is applied.

That is a little different than saying "the power supply draws the full load whether it is in use or not"

The point I was trying to make earlier is that if you are paying for heat either way (ie pellets vs electricity) then the electricity used by the pellet stove is somewhat offset by the heat put off from all the components. The same for all the other electrical appliances around the house. You could go around putting all your devices on timers so they are only "on" for roughly the time you intend to use them, but you will actually have to make up some of that electricity as heat drawn from some other source. If you get "free" heat (ie, cut your own wood) the situation changes a bit.

 

[drizler]

Want to save some electric and keep from destroying your coffee at the same time. Just unplug that mother as soon as the coffee is done pouring through it. It keeps that 1000 + watt heater element from running constantly and best of all doesn't turn your second cup of joe into a syrup like pudding. Try it and you will be amazed at how much better the coffee tastes. I discovered that one when the burner crapped out on mine years back. When it cools off just nuke it for 40 seconds and its all good.

 

[Gooserider]

FWIW, I was just checking a handful of the many "wall warts" that I have laying around - most seemed to have an output of 3-6 watts (output voltage X output current), which is their rated maximum. Because you have some inefficiencies due to the use of real world components, the input draw will be a bit higher, but probably still under 10 watts each. I could be wrong, but I think I've heard somewhere that 10 watts is the maximum that UL allows for a wall wart. A couple of larger "inline" type power supplies (battery chargers for cameras, my printer power supply, etc.) were rated in the 20-40 watt output range.

(The few such supplies that I've taken apart all appeared to be of the super simple "transformer, diode (or bridge), maybe a filter cap" design, not a switching supply. Switchers are nice, but not cost effective / worth the size / weight / complexity penalty at such small power draws - you really need to start getting towards the 100 watt draw range to make a switcher worth the effort...)

This is their "FULL POWER" draw when they are under maximum load - with no load they start approaching being a "pure inductor" aside from resistance losses - in theory an inductor draws no net power, but merely causes a phase shift between the voltage and the current

Bottom line is that wall warts draw fairly negligible current even at full load, and much less when unplugged or idling. It would take more than 10 of them to equal ONE 100 Watt light bulb. (as a very rough approximation, 100 watts is about a one Amp draw. - actually a bit less but it's a good estimation value)

Gooserider

 

[velvetfoot]

We have a coffee maker with a thermal carafe-no keep warm heating elements and you can put the carafe anywhere without worrying about burning anything.

 

[Highbeam]

"My electric bill in the summer is over $100 a month. I want to see whats costing so much."

Mine too, well year round actually right under or over 100$. You probably won't find the source with a killawatt since the major energy sucker of the summer time are on 220 like a water heater and electric dryer. The only appliance that makes up a good chunk of that base 100$ will be your refridgerator which you can use the killawatt on.

Eliminating the coffee pot will at best save me 3 cents per day which is less than one percent of my bill. A bunch of fancy footwork might save half of that but the return is miniscule compared to even the slightest inconvenience. The pot is on a timer that allows the brew to be finished just as I am ready to pour my cup. The burner then cycles on and off either as needed or on a timer to keep the coffee (glass caraffe) hot per the adjustable temperature setting. During the work week I immediately pour a cup and fill my thermos, then shut the pot off since it gets really nasty if you cook the coffee pot dry. It has a two hour shutoff feature. Really though, is a fraction of 3 cents even worth worrying about?

Goose: I love the term "wall wart". Fantasatic.

 

[velvetfoot]

Maybe electricity costs more in the northeast than the northwest, but two hours @1kW would be more here, I woud think.

 

[Highbeam]

That's where the killawatt comes in. The coffee pot uses the 1000 watts intermittently. It cycles on and off as it works. The entire brew and about one hour of keeping hot used only 0.25 kwH and at 12 cents per KWH that's 3 cents. We actually get much cheaper power here and my typical 1000 kwH month costs just about 100$ or 10 cents per KwH. If the coffee maker pumped 1000 watts into the pot constantly then it would boil and ruin the Joe.

 

[velvetfoot]

I get it now.
On another tack, I keep the KillaWatt plugged in at the kitchen counter.
The voltage reading has varied from about 115 to 121, which seems interesting.

 

[Kenny1]

FWIW, I was just checking a handful of the many "wall warts" that I have laying around - most seemed to have an output of 3-6 watts (output voltage X output current), which is their rated maximum. Because you have some inefficiencies due to the use of real world components, the input draw will be a bit higher, but probably still under 10 watts each. I could be wrong, but I think I've heard somewhere that 10 watts is the maximum that UL allows for a wall wart. A couple of larger "inline" type power supplies (battery chargers for cameras, my printer power supply, etc.) were rated in the 20-40 watt output range.

(The few such supplies that I've taken apart all appeared to be of the super simple "transformer, diode (or bridge), maybe a filter cap" design, not a switching supply. Switchers are nice, but not cost effective / worth the size / weight / complexity penalty at such small power draws - you really need to start getting towards the 100 watt draw range to make a switcher worth the effort...)

This is their "FULL POWER" draw when they are under maximum load - with no load they start approaching being a "pure inductor" aside from resistance losses - in theory an inductor draws no net power, but merely causes a phase shift between the voltage and the current

Bottom line is that wall warts draw fairly negligible current even at full load, and much less when unplugged or idling. It would take more than 10 of them to equal ONE 100 Watt light bulb. (as a very rough approximation, 100 watts is about a one Amp draw. - actually a bit less but it's a good estimation value)

Gooserider

I love this site because I'm always leaning new things. Maybe I can now offer something.

Wall warts:

More and more they are using switchmode supplies. Many IC's exist to provide cheap, off line switch mode supplies in the 4-20W range. Switchmode are typically far more efficent than the simple transformer/bridge/cap/linear regulator type. This is important as some states are introducing standby power requirements (e.g. requiring that your appliance draw a small amount of power when off/in standby mode). Power transformers (even sitting idle) will draw some power (due to leakage). Linear supplies typically draw more power in standby mode than a switcher. Some states are looking at setting standards for power supply efficenties. This will increase the numbers of switchmode supplies.


Also, some states are introducing rules about power factor correction. This means that a switchmode supply will be required. Without power factor correction (PFC), switchmodes may get to about 90 - 92% efficent (in a good design). With PFC, look for about 84 - 87% (but draws power evenly accorss the full 360 degree of the AC mains). PFC allows a supply to draw current in phase with the voltage.

Another reason to use a switchmode is that they can be made for universal mains. This means that they can be designed to work at 100 - 240VAC at 47 - 63 Hz. That means you only need one supply to ship your product world wide. For example, my Kodak K4500 NiMH Battery Charger has North American AC prongs on a molded base that slide on to the charger. If the unit were going to Britian, a different set of prongs would have been included with it.

Another reason to use a switcher is to save weight and cost. They use small lighter components than a transformer based supply (this can help reduce shipping costs). Also, power transformers are not cheap (although you would make that decision on a case by case bases).

Thermal management is also an issue (the less efficent the supply, the more heat that you have to deal with). In this regard, switchers being more efficent can have less thermal issues to deal with.

Cheers

 

[Kenny1]

Back to Iceman and your question.

I do not have your model, but I did take some power measurements last winter on my P61A.

When starting up (ignitor is on and the auger is running), the draw was 372W.

When the ignitor stops, and the auger is running and the distribution fan is on lo, the power draw is 128W.

With the auger is running and the distribution fan is on med, the power draw is 136W.

With the auger is running and the distribution fan is on hi, the power draw is 152W.

Without the auger running and the distribution fan is on lo, the power draw is 93.6W. So the auger is drawing about 35W.

Finally, in shut down mode, the unit was drawing about 46.1W.



hope that this helps.