Fridge Energy Consumption

[Fred Mc]

I read in some posts about energy consumption of some refrigerators and they mentioned figures like 1.3 amps. But when I look at manufacturers energy consumption they show figures like 321 KW hours/yr.

What is the relationship between those numbers?

Thanks

Fred Mc.

[jjrbus]

I do not think there is a relationship, I could be wrong. You have to keep looking, I know in the owners manual it says 1.9 amps also inside the fridge on a plate listing model #, refrigerant etc. it lists the draw as 1.9 amps.
When I bought the fridge there was a big yellow sticker on it that listed the KWH it is suppose to consume in a year.
                                                HTH

[belfert]

One number is the amp draw of the refrigerator when running and the other is total watts used in a year.

A low amp draw frig could have lousy insulation and have longer run times than another fridge with better insulation and higher amp draw.  You've got to find the lowest amp draw with the lowest watts used,

[Jerry Liebler]

The KWhr/yr will predict the average energy used, this will help determine how long a house battery charge will last.  KWhr/year divided by 365 is KWhr/day, KWhr/day divided by 24 is average KW used.  multiply KW by 1000 and it is average watts.  About 1.25 times average watts will be taken from the battery, due to inverter inefficiency.  The amp rating is while it is running this will be important in sizing the inverter, which must have a surge rating of about 720 times the amp rating and a continuous output rating of at least 150 times amp rating.
Regards
Jerry 4107 1120

[Nick Badame Refrig/ACC]

Hi Fred,

There are alot of factors that determine the products energy rating. Like, ambiant temps that it's operateting in, or how often is the door being opened,

is the condencer coils clean and clear...and on and on... In short, you would worry less with a larger battery bank and the ability to recharge it.

Thats my answer and I'm sticking to it...Lol

Good Luck
Nick-

[Outback Man]

I'm not sure if there is any worthwhile information to be gleaned from the yellow energy consumption stickers in the new electric refrigerators or not. I only know that one needs to be concerned with the amperage draw. I replaced the defunct gas fridge in my Flyer with a $208 Magic Chef from Home Depot  two years ago. It draws 1.7 amps on startup and then pulls around 1.3 when running.  That translates into a 17 amp and 13 amp draw through my inverter as you get about a tenfold increase in the 120 v amp draw going through the inverter. I run this with a 2000 watt true sine wave inverter running through six golf cart 6 volt batteries and have no problem with it starting or running and I am very pleased with it. It is a 10.8 cubic foot size, about the size of the gas one I replaced it with. It doesn't seem to run excessively either and I run it on solar panels and the bus alternator when on the road. I  have 5 US Solar 64 watt panels on the roof of the bus so I run everything quite well, coffee maker, microwave, TV, computer, etc. I would rather take the money saved from buying the 120 v model vs the gas and put it into an inverter and batteries as the electric one works as well as the gas and does not require a lot of fussing and leveling.

[ArtGill]

    I purchased a ref that was the old style with the freezer inside the ref door.  You know the type that you have to open the ref door and then open a small door for the small freezer.  The reason for this is to eliminate the fan that moves the cold air from the freezer to the ref portion of the box and therefore reduce the battery usage.  Just something to consider.

Art

[Jerry Liebler]

Don't be misled by outbackman.  The surge of power use when a motor starts is not easy to observe, it lasts a very short time.  The surge is often 6 times the running current. 
Regards
Jerry 4107 1120

[Nick Badame Refrig/ACC]

Don't be misled by outbackman.  The surge of power use when a motor starts is not easy to observe, it lasts a very short time.  The surge is often 6 times the running current. 
Regards
Jerry 4107 1120

Yes Jerry, you are correct!
The only way to visually see it is to use a analog meter.
Nick-

[DrivingMissLazy]

Don't be misled by outbackman.  The surge of power use when a motor starts is not easy to observe, it lasts a very short time.  The surge is often 6 times the running current. 
Regards
Jerry 4107 1120

Yes Jerry, you are correct!
The only way to visually see it is to use a analog meter.
Nick-

And even then it is very difficult to detect. The high inrush current (amps) is due to the very low power factor of the motor when starting, before any back emf has been established. This PF may be in the order of 0.2 lagging and is generally spec'ed by the manufacturer as 6-8 times full load running current at 0.9pf or higher. It really takes a good clamp-on ammeter to read this. You generally can not detect it with a standard volt/ohm meter.
Richard

[Outback Man]

I'm not sure why one would need to be concerned with a lot of technical terminology to run electrical appliances with an inverter and battery bank. I have been using the same battery bank for almost 8 years now and used a 2000 watt Hart modified sine wave inverter before I got the true sine wave one a year and a half ago. A good 2000 watt inverter with a 4000 watt or more surge will start most things. I run a 15 amp table saw, grinders, drill presses and have even used my present inverter to operate a 115 volt Miller wire feed welder. I have been living off grid for 7 years and it is not rocket science. When I was looking to buy solar equipment I found out that a lot of solar salesmen made it sound confusing and it is to some degree to a newbie, but it is a simple concept and all I know is that what I do works and works well, so running appliances in a bus is not terribly difficult.

[DrivingMissLazy]

The main thing to do is to size the inverter properly, and yours seems to be more than adequate for starting your reefer and everything else.

What we were trying to do is to warn a newbie about buying an inverter that is too small. That would be very easy to do if you only looked at the posted running amps and did not take into account the starting amps.
Richard