Small refrigerator running on 30 watts

[SternWake]

I was not aware the dorm style compressor fridges say to run them level. I knew the absorption/propane/3 way fridges are not tolerant of running off level for any amount of time, and the damage is cumulative.

Norcold and Waeco, and many other 12v compressor fridges advertise 30 degrees off level operation, as many of these fridges are designed for Sailboats, which can be heeled for days on end.

I would be very interested if the fridge in the OP consumes as little as claimed. If one is going the Inverter/ dorm fridge route, one should find an inverter which has a standby function, so that it does not consume lots of battery power just being turned on waiting for the fridge's compressor to kick back on. This function will likely eat into the savings by going for a residential fridge, and without it battery consumption will increase to some degree, requiring more electrical storage and more recharge capacity, also eating into that initial savings.

My Coleman 800 watt inverter draws 0.9 amp hours per hour just turned on powering nothing.

My Vitrifrigo c51is consumes less than that 85% of the time.

I would really be interested in seeing some measuring devices on this Sear's fridge, like a Clamp on Ammeter during start up or Shunted ammeter, or even A 'watt's up' type meter on the Inverter, or perhaps a Kill a watt meter on the AC power cord. I'd also like to know how much Noise they make. My old Norcold was a Buzzsaw in comparison to my Vitrifrigo. It reduced the quality of sleep, and many times I would climb out of bed and start punching the door in frustration at all the harmonics it would develop, which woke me up in the first place.

If you are sensitive to noises during sleep or at the edge of falling asleep I would take the possible noise factor into account, almost more so than battery consumption.

Here is my meter plugged into my 2.8 cubic foot fridge fridge: The current tapers from 2.7 right after compressor start up down to about 2.2 amps at the end of the cycle.

I've taken many steps to ensure maximum efficiency of my fridge, including more insulation, and better airflow across condenser and compressor so that it cannot recycle any preheated air. It does not need these modifications, the compressor on my fridge could power a fridge 3x the size at max rpm, however I did it for maximum lifespan and minimal battery draw, and I am thoroughly impressed with its performance.

 

[SternWake]

I'd really be interested in seeing actual power consumption over a 24 hour period with this fridge, including inverter losses.

Some might roll their eyes at my repetitive nature on this topic, but inverters are only so efficient, and most inverters do not have a no load standby feature which causes it to draw very little energy when no load is applied, such as when the compressor is in between cycles

My one MSW inverter draws 0.9 amps when turned on powering nothing.

My 12v compressor Vitrifrigo draws less than this inverter will, powering nothing, over an hour.

If one factors in the inverter cost, and extra batteries and charging sources required to run the fridge, then a dedicated 12v compressor fridge is not really more expensive.

If the residential fridge does not like the travelling vibrations/ stresses and fails early, then the 12v fridge just became cheaper.

This could be a false economy, save a little now, pay a lot more later to do it right.

 

[Simran]

The inverter may well be the elephant in the room. This has been my thinking from the beginning, however, I am open to someone proving us wrong on this account. I would actually welcome it because my little fridge has an even smaller freezer.

 

[VanLifeCrisis]

I might not be too informative there, i dont plan to buy a kill o watt meter to see. Just going to see if it keeps my food cold or not

 

[Simran]

I don't think anything like a scientific study needs to be done. Time with the unit hooked to a solar panel and batteries should to tell the story.

I might not be too informative there, i dont plan to buy a kill o watt meter to see. Just going to see if it keeps my food cold or not

 

[Ballenxj]

Hi SternWake, (You must be a Sailor?)
I'm interested in hearing about your Vitrifrigo 12v fridge, and if you have any more info or links pointing to the inverter with standby capabilities I would appreciate it.
Meanwhile I will try and search for information on these things.

---

Ah, Found the spec sheet for Vitrifrigo Refrigerators.
http://vfsales.com/images/Undercounter_single_door_v1.1.pdf

There is a lot more to research in the power inverter scene, so haven't found what I'm looking for yet.

 

[SternWake]

I apologize for posts 22 and 23 being repetitive. After posting 22 it was not showing up despite multiple attempts, and after losing it and a cursing fit, I typed post 23.

Very surprised to see 22 did show up just now.

I am not a sailor, but do have some boating experience, and frequently look to the marine industry for solutions to Rv dwelling.

I am not up to date on all current inverter technologies in regards to those which have an auto sleep mode when no load is applied. My 800 watt coleman is a decade old and a bit reviled. I am not sure I've even used it since I got my PSW Wagan 400 watter which is much quieter with half the standby current. I bought this primarily to power my Makita Li-ion battery charger as I am not willing to risk damaging it on a MSW inverter, and now just use it for everything I use an inverter for, which admittedly, is not much Mostly heating pads for my Stiff neck, or to rest my Shower bag on for when I am out surfing.

My old Norcold fridge had a loud Sawafuji compressor and I spent way too much time and effort isolating it from the cabinet in which it resided to reduce noise/vibration and also increase thermal insulation and airflow across compressor and condenser. It lasted about 5 years running 11 months a year before failing.

I replaced it with the Vitrifrigo with the Danfoss/Secop compressor, which I am much much more impressed with. In terms of both efficiency and noise created.

The benefits of the Danfoss extend beyond the noise and efficiency though, as the compressor controller has the ability to use options, like increasing or decreasing compressor speeds, or hooking another fan to the controller to exhaust hot air from the cooling unit compartment, when the compressor is running. Also the condenser is like a small radiator with a fan attached directly to it, rather than the large passive condenser like on the Norcold. I removed replaced and relocated this fan to the other side of the condenser to push air(quieter), and created a cooling unit tunnel to not only protect the cooling unit from installation/removal stresses, but to direct the fan's airflow across the compressor and compressor controller before being pushed out a louvered vent, or into the adjacent cabinet in wintertime.

This single pass airflow of ambient air across the condenser is probably the single best way to ensure maximum efficiency. Extra insulation is a a huge benefit too. The door seals are where more improvements lie, but honestly the fridge's battery consumption is the least of my concerns now. I have installed a small interior fan which runs 24/7 too for 0.03amps and while this does not reduce battery consumption, it greatly evens out interior temps and allows a much lower thermostat setting. I use it on 2 of 7 to keep the interior under 35f where as nearly 4 of 7 is required without the internal fan. I've no doubt turning it up higher would make it into a deep freezer with the aid of this internal fan

There are other options for a Danfoss/Secop powered refer that are cheaper. Vitrifrigo is assembled in Italy and I figured Vinchenzo cares more about his work than Chin ho, so I paid the extra and am glad I did.

Look into TruckFridge for the least expensive Danfoss/Secop powered refers.

I bought my Vitrifrigo from :
http://www.westyventures.com/parts.html#cart_restore

Unless one already has a dorm powered fridge, or a large inverter or both, I'd really recommend getting a 12v compressor fridge powered with a Danfoss compressor over any other method of refrigeration.

I bet my Vitrifrigo fridge as I have it installed, is among the most efficient on the planet, and while I loved the convenience of the Norcold, and it did a good job at keeping sub 40f interior temps for those 5 years, it did cause me much aggravation in terms of noise, harmonics and the desire and efforts to minimize those. At the end it was literally floating inside a cabinet filled with different layers of different densities of foam rubber and other insulation methods, yet would still start silverware rattling in the sink.

I don't know how loud the residential fridges are in comparison. But for me noise is a huge factor.

I'd be interested in knowing about the auto off/ standby inverters as I have not researched these myself, but if one is really planning on a residential fridge, then this type of inverter should be considered mandatory, as long as battery consumption is a concern. If one regularly has access to grid power or lots of excess solar, then not such a big deal.

Unless the dang thing is a Buzzsaw and affect's one's sleep cycle

 

[Unchained]

Sorry, SternWake. Post #22 got caught in the spam filter. I found 3 copies, so I approved one and binned the other 2. Let me know if you want post #23 removed.

 

[psytechguy]

The Morningstar SureSine 300 pure sine wave inverter has a standby feature. Also a low voltage disconnect.

From the manual:
"Standby – The AC output will remain off until an AC load greater than 8 Watts is detected. When the AC load falls below 8 Watts, the AC output is turned off."

 

[highdesertranger]

I tried the dorm refer for my first attempt to get off the ice addiction(2009). basically it didn't work with 65 watts solar 2 batts and invertor. 90's daytime temp, refer was running way to much. those small dorm refers are energy hogs. it was a good thing we still had ice chest that year but it was a 5 hour adventure to get more ice. so the next year bought an engel I was so impressed with the low energy consumption and performance, that the next year I bought another and got rid of all the ice chests. so now with 160watts solar 2 batts I have plenty of power. when I build my toy hauler trailer I will buy one more to use as a freezer. btw they work great as a freezer. highdesertranger

 

[SternWake]

Thanks Unchained, I was wondering what was going on. rereading the second post, I guess it is not too repetitive, not enough for most to believe me to be mentally unhinged anyway.

A 300 watt inverter "might" not handle the start up surge on any particular residential refer. I know of one guy on another forum whose 400 watt inverter would not run the dorm fridge he bought, so he went out and got a 1000 watt and that would not start the compressor either and he finally wound up with a 1500 watt inverter which would handle the start up surge. I think the advertised running wattage was under 100. He was not a dweller, more a Vanner who wanted a fridge to keep his beer cold over a long weekend for an Event, and was woken up to his inverter low voltage alarm the very first night. Not sure how much battery capacity he had and how healthy those batteries might have been though.

All fridges will vary in their efficiency. Many of the low dollar ones available in the home stores couldn't give a rodent's behind about how much electricity they consume, and give no thought in how to dissipate the heat removed from the interior of the fridge, which IS the primary function.

The 12 volt models are designed with battery power in mind. The dorm fridge route might work. it might not. It will use more battery power. It very well might cost more in the long run, perhaps in the short run.
A kill a watt meter is only like 25 bucks. if one already has a dorm fridge and wants to use it in a rolling residence on battery power, this device can tell you how much battery power and recharge capacity one would need, If the ambient temps were the same as in the rolling residence, and adding 15% to the total for inverter inefficiency. And perhaps another 25% if the inverter does not have the standby feature.

 

[davidjoe]

HELLO FOLKS,
I WOULD LIKE TO GIVE AN HONEST REPLY TO THE 30 WATT KENMORE REFRIGERATOR SUPPOSED LISTED ON YOUTUBE.........THE FRIDGE IS NOT 30 WATTS IT IS 115 WATTS. I DONT KNOW WHERE THIS PERSON GOT HIS INFORMATION BUT I SEARCHED THE MODEL NUMBER WHICH IS ACTUALLY SEARS ITEM NUMBER 04695693000P AND LOCATED ONE AT SEARS IN PRYOR OKLAHOMA, THE STORE MANAGER ACTUALLY LOOKED UP THE WATTAGE ON THE BACK OF THE REFRIGERATOR AND IT READS 115 WATTS. SO THERE YOU HAVE THE TRUTH. that still is pretty low wattage at 115 watts but its not 30 watts. i dont think you can find a 30 watt compact refrigerator anywhere. I THINK THE PERSON ON YOUTUBE DOES NOT UNDERSTAND HOW TO PROPERLY READ WATTAGE. IT IS ACTUALLY LISTED ON THE BACK OF THE UNIT ITSELF. EDGESTAR AND SPT ARE GOOD LOW WATTAGE BRANDS OF MINI COMPACT REFRIGERATORS TO CONSIDER WHEN BUYING. hope this helps

 

[VanLifeCrisis]

HELLO FOLKS,
I WOULD LIKE TO GIVE AN HONEST REPLY TO THE 30 WATT KENMORE REFRIGERATOR SUPPOSED LISTED ON YOUTUBE.........THE FRIDGE IS NOT 30 WATTS IT IS 115 WATTS. I DONT KNOW WHERE THIS PERSON GOT HIS INFORMATION BUT I SEARCHED THE MODEL NUMBER WHICH IS ACTUALLY SEARS ITEM NUMBER 04695693000P AND LOCATED ONE AT SEARS IN PRYOR OKLAHOMA, THE STORE MANAGER ACTUALLY LOOKED UP THE WATTAGE ON THE BACK OF THE REFRIGERATOR AND IT READS 115 WATTS. SO THERE YOU HAVE THE TRUTH. that still is pretty low wattage at 115 watts but its not 30 watts. i dont think you can find a 30 watt compact refrigerator anywhere. I THINK THE PERSON ON YOUTUBE DOES NOT UNDERSTAND HOW TO PROPERLY READ WATTAGE. IT IS ACTUALLY LISTED ON THE BACK OF THE UNIT ITSELF. EDGESTAR AND SPT ARE GOOD LOW WATTAGE BRANDS OF MINI COMPACT REFRIGERATORS TO CONSIDER WHEN BUYING. hope this helps

Yes, tho it runs as low as 70 in regular use, but it does run around that for a little so i guess reality is somewhere in tbe middle.

Not sure how he got 30 in that vid.

 

[GotSmart]

HELLO FOLKS,
I WOULD LIKE TO GIVE AN HONEST REPLY TO THE 30 WATT KENMORE REFRIGERATOR SUPPOSED LISTED ON YOUTUBE.........THE FRIDGE IS NOT 30 WATTS IT IS 115 WATTS. I DONT KNOW WHERE THIS PERSON GOT HIS INFORMATION BUT I SEARCHED THE MODEL NUMBER WHICH IS ACTUALLY SEARS ITEM NUMBER 04695693000P AND LOCATED ONE AT SEARS IN PRYOR OKLAHOMA, THE STORE MANAGER ACTUALLY LOOKED UP THE WATTAGE ON THE BACK OF THE REFRIGERATOR AND IT READS 115 WATTS. SO THERE YOU HAVE THE TRUTH. that still is pretty low wattage at 115 watts but its not 30 watts. i dont think you can find a 30 watt compact refrigerator anywhere. I THINK THE PERSON ON YOUTUBE DOES NOT UNDERSTAND HOW TO PROPERLY READ WATTAGE. IT IS ACTUALLY LISTED ON THE BACK OF THE UNIT ITSELF. EDGESTAR AND SPT ARE GOOD LOW WATTAGE BRANDS OF MINI COMPACT REFRIGERATORS TO CONSIDER WHEN BUYING. hope this helps

Are you sure you know what you are talking about? You must have volts and watts mixed up. My dorm fridge is listed as 115 volts. No watts listed on the plate. Just amps. The store manager is the last person you should rely on. Get the information direct from the plate yourself. The person was talking about running a 115v fridge on 12v conversion, and it was using 30W an hour in power.

(All capitals is annoying!)

 

[Zil]

Agree. The plate will read 115 volts and have an ampere rating. I have yet to see anything with a motor (other than small fan) rated with watts.

 

[anm]

I think the OP said he got the 30 watt figure by using math on the estimated yearly consumption. The only problem with that is it assumes the frig is running 24/7...

 

[GotSmart]

Most are.

 

[anm]

No, most don't, the compressor cycles on and off dependent on the internal temperature...

 

[GotSmart]

I see what you mean. In my mind, running meant plugged in and working. (Is your fridge running? Better go catch it!) average usage over the day with all cycles figured in.

You mean actual compressor running at full draw.

So actual will be about 1/3 the 30 watts per day?

 

[anm]

Assuming the EPA power consumption figures are accurate (270kWh/year = 30 W/hour), and if we assume a 50% duty cycle on the compressor, the actual peak draw would be 60watts for half the time and the compressor not running at all for the other half. Total power consumption is the same, just the peak current is now 5 amps (60watts divided by 12v) instead of 2.5amps (30watts divided by 12v).