# refrig power usage???

ok as i am in the planning stages of building an off-grid system for a house in mex. I have been reading up on AE and conservation etc to utilize in the planning of the house. I also have little knowledge of my current usage. other than it cost X amount of dollars on my utility bill. I dont even know much my utility bills is normally. But i have been taking a look into things and it is looking like i am using around 1,500 kwh per month give or take. I dont know if that is a lot of not, so i read an article on doing a home load test. so i ran around to a couple of appliances such as my refrig.

It is an older 27 cu ft side by side with an ice maker and water in the door. I looked at the tag and it said 11.6 amps on 120v. so unless i am misreading the math. You take the 11.6 amps * 120v = 1392w then figuring a 25% droppage cause it is not trying to cool from house temp to set temp. you get 1044w. and assuming the refrig runs a quarter of the day to maintain the temp i figure 8 hours a day. so at 1044w * 8 hours = 8352w per day. or 8.3kwh per day at 8.3kwh per day * 30 days in a month = 250.5kwh per month. or 15% of my monthly energy usage so i am planning on running over to home depot to take a look at the load difference of energy star refrig.

did i misread the math or are those numbers viable? thanks for any help and how much energy am i looking at saving by going with a 25-27 cu ft energy star refridge

Re: refrig power usage???

The math looks good but the 11.6 amps isn't realistic of typical load.  My Kenmore model 363.9550950 has the same 11.6 amp rating but my Killawatt meter ( http://www.supermediastore.com/kilwateldet1.html ) shows just over 200 watts when in cooling mode.  The ice maker has a heater to melt the cubes a little so they dump when the tray empties into the bin, there is a motor to dump the cubes, a motor to power the auger that drops the cubes out of the door, the frostfree feature is a heater by the evaporator that melts the frozen condensation that forms on the coldest part of the unit.  I haven't seen the Killawatt when the defroster is on but the highest wattage I have seen is ~400 watts when the heater for the ice cube tray comes on prior to dumping the tray.  It seems that the compressor was cooling at the same time, IIRC.  My 'fridge runs about 10 to 12 hours per day, a little over 2 kwh.  Don't spend your money on a new 'fridge yet, here http://www.wind-sun.com/smf/index.php?topic=1439.0 is a thread that discussed it pretty well.

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Re: refrig power usage???

You really need a kill-a-watt meter to measure your power use over time. For myself, I have been using an old 120 VAC utility meter + socket + cords and just plug my loads into that. A Kill-A-Watt meter is only \$33 from Amazon right now (free shipping), and I have seen it cheaper on occasions:

http://www.amazon.com/gp/product/B00009MDBU

You will probably want to run any of your test loads for few days or week at a time so that you can look at your average loads. Name plate loads are, almost always, peak/worst case ratings and for items like fridges and such that cycle on their own, are not really good enough to make any reasonable estimates.

However, my first home 18 years ago, I measured the old 17 cuft clunker that was in there and was shocked to see it was running about 170 kWhrs per month (~\$17)... So, you SWAG does not look out of line at all for me.

All of the new appliances have the estimated energy usage ratings on them... They will tell you the cost in dollars--but you really want to also look at the kWatt*hours too--For California, the electric costs are about 1/3 too low (and change over time). The newer 20 cuft units should be using around 600-700 kWhrs per years or so or much less than (50 kWhrs per month +/-).

My fridge was the first "conservation" purchase that I made... Every purchase I have made since, I have been looking at the energy tags (and/or name plate ratings for TV's and such).

You can also estimate big uses by comparing your winter/summer bills and take a guess at your A/C costs too (assuming that you don't have electric heat).

-Bill
Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
Re: refrig power usage???
jakestorm wrote:
in the planning stages of building an off-grid system for a house in mex. i am using around 1,500 kwh per month give or take.
Just a question. Are you planing on continuing to use what I consider to be huge amounts of electricity, or are you seriously going to look at reducing energy useage? It costs far less to conserve, then to produce. AE, or grid, but especially AE.
In my humble opinion, unless one is quite rich, one must change his/hers whole way of thinking when going AE. The energy that we as a Western society waste, hour by hour, day by day, is nothing short of criminal.
By the way, my computer is running on solar power stored earlier today, as are my lights and "chest fridge" and a bunch of other stuff.
And, if all goes well, by weeks end, my hot water will also be solar.
Wayne
Re: refrig power usage???
In my humble opinion, unless one is quite rich, one must change his/hers whole way of thinking when going AE. The energy that we as a Western society waste, hour by hour, day by day, is nothing short of criminal.

The problem is that by world standard, the US is quite rich. Pretty good wages, relatively low taxes, and low prices. I try not to judge people too much--but instead just try to help educate. Even the poor in the US are quite well-off (over weight being the problem, not malnutrition).

It is easy to focus on energy costs as being excess (whether it is somebody else's spending \$200+ per month, or my own at \$40-\$60 per month--pre solar). When the reality is my power bills are dwarfed by my personal health insurance charges for my family of four, property taxes, income taxes and such.

I could afford to put money into insulation, double pane windows, and solar panels. Choose to drive a smaller car eventhough I can easily afford to drive a bigger one, etc.

Life it too short to worry about how others choose to live life. I try to make it a little better for myself and others (near and far) around me. But I will not go to the Sudan and live on one dollar per day per person (\$360 per year). You can bring everyone in the US down to world income averages pretty easy--it is however, very difficult to bring the world's income up to USA's averages (currently around \$30,000 per family per year). Is that fair--probably not... But it is real life.

-Bill
Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
Re: refrig power usage???

well i had no idea what my usage was for electricity like i said i dont even know what i pay a month i think somewhere in the 300-500 range. you probably dont want to hear what my 1st house in AZ was pulling. with crappy insulation and an A/C on its last leg. i would guess it was 2000 to 2500Kwh when i was at that house, and i live alone.

I am going to be taking more of a look at my energy usage as a whole and with planning this other house building i am paying more attention to it's energy effectivness as it will directly translate into more cost to provide the type of electricity i am currently using. It all boils down to dollars and cents to me. As far as weighing the cost of an RE source vs when it will pay for itself. so right now i move a lot. I am in my 6th house in 2 years. I buy houses fix them and resell them along with my construction company. I will stay in the house i am in for awhile but i dont plan on having it for 10-15 years that is would take me to pay off a system.
Re: refrig power usage???

This is probably even a better reason to look at conservation... For yourself, having a small, efficient 15 cuft fridge stuck in a corner somewhere and and an efficient AC window unit to cool a room or too, gas stove to cook out side (you are probably doing kitchen remodels too), a couple CPF lights for the rooms/lights you use a lot--that you can take with you from "site" to "site" may be a better deal than just using the 27 cuft fridge and whole house AC for the short times you are there.

And/or, if you are remodeling homes for a living--see if adding insuallation, new energy star appliances, new heat pump heating/cooling, solar hot water (usually cheaper and better return than solar PV panels) and such can get you a better price when you flip the homes. It might be nice to have a recent utility bill for the prospective owners to see how they can save money with the conservation investments...

But, that stuff costs up-front money for you, and not all home buyer's will appreciate the effort--which, in the end, may not make any money for you to install in the first place. Life is is tough and you have to make tough choices.

Good Luck,
-Bill
Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset