Home refrigerators for buses

[belfert]

I am looking to get a larger 110 volt household fridge for my bus.  I have looked at a Frigidaire Energy Star model that is 355 kilowatts per year and a Whirlpool non-Energy Star that is 430 KW per year.  Do you guys (and gals) think I will really notice the 20% higher energy usage when boondocking?  Whirlpool is generally rated better than Frigidaire plus the Whirlpool is around $100 less expensive.

The original reason I started looking for a new fridge is because my Haier was not cooling evenly.  I found out it doesn't have a circulating fan because it is manual defrost.  I added one of those battery powered fridge fans and the cooling is 100% better.  I still really need more space so I still looking at new fridges.

[Ray D]

I am going to use a home fridge, but the energy star ratings are very confusing, they don't tell you how much they use, but what the yearly savings and use is.  They don't say how they come up with this number at all, I think it is probably the same way they come up with MPG for new cars.  You look at there sites and it is almost impossible to find an actual amperage draw.

Ray D

[Lin]

Without knowing the amperage of each, it is difficult to say which is better.  However, if the efficiency ratings they give are based on amperage, which would make sense, then a frig. that drains your batteries 20% less quickly would seem to be a worthwhile advantage.  If you can find the amperage of each, you could do the calculations and see how long you will be able to run them before starting the generator.

[Sean]

Brian,

Outside of HVAC, a refrigerator is the single largest energy consumer in a typical home.  Most household fridges use well over 1,000 kWh per year.  A good average is 3-4 kWh per day.

To put that in perspective, the average household fridge consumes about 150 amp-hours each day from a 24-volt battery bank, or 300 amp-hours each day from a 12-volt bank.

The single biggest improvement you can make to any household fridge, is to disconnect the automatic defrost system, and manually defrost the fridge when necessary.  Alternatively, you can build a system of relays to re-activate the frost-free feature when connected to shore power.

I don't think the Energy-Star model you are looking at will really use only 355 kWh per year.  Those numbers are for comparison purposes only, not intended to figure your actual usage.

If you really intend to boondock extensively with an electric fridge, your best bet is to go with a 24-volt marine model.  Those are pricey, so you can do almost as well by buying the cheaper, smaller, no-frills household model and a pure sine waver inverter (the losses are just too great with MSW).  Disconnect the frost-free system, and surround the unit with as much styrofoam as you can, 1" or more is best (everywhere except the coils, of course).  Efficiency can be improved by flushing heat from the coils with a small muffin fan, depending on where and how you plan to mount the fridge.

Hope this helps.

-Sean
http://ourodyssey.blogspot.com

[belfert]

Energy Star refrigerators have to use at least 20% less energy than a similiar non-Energy Star model.  Frigidaire has two otherwise identical models, one Energy Star and one not, and the Energy Star one uses 21% less energy.

Every fridge is required to have a Energy Guide that lists how many kilowatt hours will be used in a year on average.  This is the guide I go by when figuring how much energy a particular fridge will use.

Do NOT use amp draw as a guide.  I picked my current 10 cubic foot Haier because it has a 1.2 amp draw.  I never checked the Energy Guide on the Haier at purchase time.  The Haier is actually rated at almost 400 KW per year which is really bad for a 10 CF fridge especially not being frost free.  The fridges with frost free will be around 4 amps or more because of the heater for defrosting.

[belfert]

Sean, I am just using the Energy Guides as a relative comparision of energy efficiency. 

The 24 volt fridges would be the way to go if one was going to boondock fulltime like some do.  I simply don't get enough use out of my bus to justify upwards of $2,000 for a fridge.  I do have a true sine wave inverter so I am set there.

[Lin]

I guess my previous post suggesting comparison by amperage draw was inaccurate.  Comparing amperage would only be of value if the boxes were equally insulated, and comparable in most ways.  My bad.

[TomC]

What about adding a chest freezer?  Norcold makes dual voltage ones-I have one and it is very convenient-extends refer usage out several days over the normal refer.  Good Luck, TomC

[buswarrior]

The big scam in house refrigerators, as best as I can tell...

The low end models rate poorly, the high end models rate better.

The difference? You get to pay lots more money for a better insulated box. Doesn't seem to make much difference on the business bits, it's how long the thing has to run and how soon it has to come back on due to losing the cooling.

For occasional busnut use, buy a big cheap one and super insulate it, as Sean has noted.

From the distant past, busnuts who have journeyed this way before:

Add styrofoam to all surfaces, door too, and re-skin with the material of your choice. Disconnect the coils on the back and ease them out further to slip a thinner piece of foam down the back.

Some models have power robbing heaters in the door edges to prevent condensation. Check the schematic and disconnect those too.

The accumulated knowledge one gains from these boards is simply astounding!

happy coaching!
buswarrior

[Nick Badame Refrig/ACC]

Hi brian,

There are plenty of household reefers out there that are plenty efficient for boondocking. First, like you did, look for energy star rating.

Second, look for a reefer with a static condencer. "the condencer is on the back wall with No fan"  Then find one with manual defrost system.

If you cant find one with manual defrost, then it's quite simple to tye in a switch on the timer curcuit to defrost when you can. Then you are

left with the compressor which most all of them are as efficient as they come. I have a Frigidaire counter depth side-by-side in my bus that is

energy star rated and claims to draw 3.8 amps in refrigeration cycle, but, it draws 4.9 amps. That is still good for it's size and I can run it 2

whole days on my batt bank of 1000 amp hours "along with lights and tv" before needing to recharge. Of course, you will have the problem

of latching the door while traveling... BTDT..

Good Luck
Nick-

[luvrbus]

Belfert, SunFrost was always high on my list till I read this from AZ Sun&Wind 
http://www.windsun.com/general/sunfrost.htm  if I got it right.Have you checked into the propane refrigerators the Amish use I have a friend that uses the Miller and loves it the beer is always cold even here in Aug in the AZ  heat              good luck

[H3Jim]

I have a Sunfrost, the 16 cu ft model.  I've had it for about 3 1/2 years and I am very happy with it.  I park my bus on the lower p;art of my lot and do not plug it in, but I leave the refrigerator running 24/7.  I also have solar panels, and my house bats and start bats are always fully charged.

I have had no issue with the seals and I find it keeps food much better than the fairly new refrigerator I have in my home.  Much less  freezer burn, and produce in the refrigerator stay much better.  I attribute that to the facdt taht it has two compressors, so there is no airflow between the regrig and freezer.

I have a drain installed, and I have not had any issues with excess water etc.

It was pricey, $2700, although I saved shipping as I picked it up from the facdtory in northern Ca.  I thought the owner of the company was an @$# and did not treat his employees very well.

There is a direct path for sound from the comopressors to my bed, but its not loud enough to bother me.

[belfert]

It is unlcear to me who actually tests refrigerators for the Energy Guides.  Is this done by the government? 

It is next to impossible to find a full sized fridge that is Energy Star rated and manual defrost.  I didn't see one on the Energy Star list except really small units or refrigerator only units.  I will just have to disconnect the auto defrost.

[Oregonconversion]

ENERGY STAR is a joint program of the U.S. Environmental Protection Agency and the U.S. Department of Energy helping us all save money and protect the environment through energy efficient products and practices.  (from their website)


http://www.energystar.gov/

Don't forget that you get tax credits when using ENERGY STAR products.


I don't think it will make much difference when ran off a generator most of the time though.

[belfert]

I don't see anything about Energy Star refrigerators being eligible for any sort of tax credit or tax deduction.  If each manufacturer does their own testing for Energy Star and the Energy Guides that could call the whole thing into question as manufacturers would have a lot of incentive to cheat.  LG had to pull Energy Star ratings from some refrigerators recently as they didn't meet the criteria.

Most of the time I am running off of battery.  If I was running off generator or a pole I wouldn't care too much about how much power my fridge was using.