chest freezer kwh in full day

larcal

Hill_Country said:

Here's a usage table put out by Steca for the approximate energy requirements for various ambient temperatures and different fridge/freezer temperatures for their two DC models (PF166 and PF240).  Hopefully this helps others.  The Stecas come with a drain plug on the bottom for emptying residual water.  Condensation is definitely an issue for us here in Central Texas and we have to wipe the bottom of our fridge out every 2 to 3 months, depending on how humid it is.  Remember, however, that our off-grid place does not have air conditioning.  Both Stecas are inside. 

Also, keep in mind the operating temperatures for these units are from 50 deg. F to 109 deg. F.  Not sure what would happen if you are below the minimum operating temperature.  Just something to consider. 

Hill Country, just asked you about Stecas in this thread--http://forum.solar-electric.com/discussion/24529/energy-efficient-120-vac-fridges-vs-sunfrost-dc-fridge/p2  because hadn't found this thread yet. Allow me to also ask here why is necessary to keep bottom real dry as you say? Is it to prevent tube corrosion? Have had this problem on Sundanzer because found out too late that bottom seams not sealed and water leaks thru to  tubes underneath. Horrifyingly, such tubes are steel, so two strikes against them. Other people now recommend you seal seams with silicone bead

Do you recommend a dry floor because you think Stecas are also not factory seam sealed? At any rate I have read in two places that Stecas have aluminum evaporator lines underneath floor and will not corrode nearly as fast.  http://ntmtechcenter.org/tech-updates/2014/sundanzer-rebuild-kit/   (Mentions Stecas in middle of article about Sundanzer).

Also mentioned here if scroll down to fridges, https://survivalblog.com/solar-power-crash-course-by-k-k/ 

Even so, would hope factory seals this, if anyone here knows

Another concern you bring up here that I hadn't realized is that the Stecas minimum ambient temp is 50F. Have had my recently defunct Sundanzer in outbuilding with very low ambient temps in winter, often below fridge setting of 35F degree. Sundanzer manual (I just realized) says if ambient is close to internal temp the appliance will get colder then it is set for and you'll have to increase thermostat setting.   Doesn't sound like a big downside but not sure about Steca or what risk is and seems to be no way to ask Steca about this and other concerns. Hopefully someone here knows a good contact. 50f seems  pretty high, worse then way Sundanzer says it.

Hill_Country

Larcal,

So far both our Steca's (a PF166 (5.8 cu. ft.) and a PF240 (8.5 cu. ft.)) have been stellar.  We've had them running for just over a year and two months and are very pleased at their performance thus far in terms of keeping food cold and using very little energy.   We have not had to defrost our PF240 yet, which we are using as a freezer.  However, I'm guessing that in the next year we'll probably need to defrost as there is frost that is starting to build up (less than 1/2 inch thick at the worst part).  One nice part is that the Steca's can be used as a fridge or freezer simply by adjusting a couple buttons on the handle LED display...that's it. 

We are using the PF166 as a refrigerator and have a super absorbent dish towel in the bottom in order to soak up the condensation.  We wring out this absorbent towel maybe once every 2 - 3 weeks or so.  Both Steca's have drain plugs on the bottom which allow you to easily drain the chest refrigerator/freezer...but the absorbent dish towel does the trick just fine and we don't have any issues with mold.  We don't mop up the PF166's condensation to prevent corrosion or anything...we just don't like having too much moisture on the bottom for when you put items in there and you go to pull them out and they're dripping.

I feel that both Steca's were definitely worth the premium, especially since we're off-grid and that is our primary, full-time load.  We can shut down the inverter if we're away on a trip and we can still keep our fridge and freezer going.  Was it the cheapest solution?  No, but it was the right solution for us.  Obviously each person's setup is different and folks have different priorities.

I have not contacted Steca about the minimum ambient temperature requirements and what they actually mean (i.e. why there is a 50 deg. F temperature minimum rating).  If I find out I will let you all know. 

larcal

Hi Hill. appreciate your answer. Yes we also mop up the bottom occasionally just for aesthetics, and the sundanzer has a drain plug also. But the plug can not left open when running or humidity gets sucked in. So with slightly imperfect maintenance of a busy life some water leaked thru seams and caused corrosion of steel pipes. 

One clarification please. I gather you have no knowledge of seams otherwise, but can you see any evidence just looking at seams that maybe they are sealed? 

At least if does leak pipes are aluminum so still better off. Maybe still some corrosion but a lot slower.

USA Steca distributor tech department knows nothing about Stecas nor do any dealers. And I do mean nothing. That's why wrote this forum. Am today trying to open contact with Austria. Will inform if any luck.

Sundanzer sucks tho, nor do they care. And Billy is gone.

Amazing about those missionary techs in link above, don't ya tink? Would not have known about Steca tubes otherwise. They rebuild Sundanzers in primitive villages!!.  But can't contact them unless a missionary or at least doing church work.

Yes, dc coolers are great. We keep extra inverters around of course but still get a good feeling from not being dependent on them for life essentials. Self sufficient as possible is the ideal. Hoorah

And even if is possible to get within 20% of energy use with an AC unit it is not just a matter of adding extra panels as some seem to think. Round here in winter can go weeks without sun and every watt burned comes from gas, no matter how many panels you have, which needs town. If Steca don't work out will maybe have to look into AC though. Find out If there is an efficient model with bone solid durability which is doubtful in this age. Use small dedicated (probably Chinese) inverters and budget in several inverter replacements for next 30 years 

Just ruminating in case it helps someone sometime approach the holy grail.

Best 

larcal

Hill_Country

Could you please glance at the bottom seams and report whether you see any evidence of sealing like an extra thick bead or something? Maybe push on it a little?

Hill_Country

I will report back what I find in terms of seams in the Stecas...hopefully this will help others!

larcal

This sounds like you are going to talk to others and report back which is super. Thank you. 

In the mean time, while we wait, are you indicating you can see no visible evidence in yours? Usually a sealed joint has an obvious bead or thickening  but not always. At any rate, this query was started because you said you owned 2 of them so I thought was a simple and natural request.

Hill_Country

Actually I will check and see what our two Stecas have in terms of seams on the lower, interior portion of the fridge/freezer surface.  I'll report back here what I find when I get a chance to look.

WaterWheel

Home Depot has a 10.6 cu/ft chest freezer on sale ($298 plus $58 shipping) that uses a claimed .58 kwh/day.     The side plate shows 1.35 amp draw at 120v.      That's less power than my 5 cu/ft freezer uses so I got one.       It's only been running a few hours so too early to put a meter on it but the insulation is impressively thick.

Hill_Country

@larcal

I looked at the interior of our Steca PF 166 and there is, indeed, a seam along the bottom (i.e. there is a very small seam between where the interior surface is joined together along the perimeter of the bottom surface on the inside of the fridge/freezer).  Not sure if there is sealing behind this initial, interior layer. 

jonr

I'd give up some amount of efficiency if a freezer had thermal storage and an oversized compressor such that it only needed to run for 6 hours/day (ie, while non-battery solar or generator power is available).

Dave Angelini

jonr said:

I'd give up some amount of efficiency if a freezer had thermal storage and an oversized compressor such that it only needed to run for 6 hours/day (ie, while non-battery solar or generator power is available).

You probably will have to build your own. The one I built for my sailboat was a dual plumbed holding plate freezer/reefer. It had 2 cooling loops. One for an engine driven compressor and one for a Danfoss DC compressor. It would hold for 3 days in the tropics.

The standard gear in this thread needs to run every hour or 3. There is decent insulation but not enough material to "hold" the cold.
The holding plate system had about 4 gallons of liquid in a reefer plate and a freezer plate. If interested look at Marine refrigeration.

vtmaps

jonr said:

I'd give up some amount of efficiency if a freezer had thermal storage and an oversized compressor such that it only needed to run for 6 hours/day (ie, while non-battery solar or generator power is available).

This has been discussed many times.... search this forum for the word "eutectic".  You will find many hits, including this one from a new guy named Dave Sparks.

--vtMaps

Dave Angelini

Hey Michael !  How is the wrist doing? The naproxen pre-med has been working well for me and the doc did not have to cut me.
Any fish this summer?