My latest freezer converted to fridge showing VERY good results.

[waynefromnscanada]

Well folks, this is the third freezer conversion I've made and am providing some info here for those who may be interested.
The first was a small upright that I found to be a pain in the butt when it came to reaching down into the bottom layers to retrieve the milk etc. And even though I had installed shelves, things still got lost and forgotten in the bottom until it was too late. Thus the next, upright five point something cu ft, which worked great! However, after a year of struggling with its small size, comes the latest and hopefully last!
This one is a Sears 8 cu ft, Model 461-99192. And yes, I've modified the starter circuit so it will start and run off the Morningstar 300 inverter, but that's another story for a later time. Right now I want to share what I consider to be it's amazing electrical efficiency as a "fridge".
I've had it plugged into my Kill-A-Watt checking consumption, and 12 hours ago, reset the meter. Now, 12 hours later, it has consumed, get this: 0.12 Kwh! Yes this was overnight, but the door was opened a couple of times after resetting the Kill-A-Watt. I'll be keeping an eye on this for a few days, but so far, this is roughly where it's consumption seems to be heading. When I first did the conversion, it only ran for about a minute at a time, the thermostat I had was too sensitive, and since the compressor's consumption is higher during that first minute, (up to 200 watts after start, settling to 125 after one minute) the average consumption was at least twice what it is now that I've decreased the sensitivity of the thermostat so it runs roughly 5 minutes each cycle. It remains off between cycles, roughly 45 to 50 minutes or longer unless the door is opened. Haven't timed it exactly yet. By the way, trial and error has shown that the best value of start capacitor, for those who might use one (requires electrical modifications that will void warranty) is 74 MFD. This value is hard to come by, but critical if further converting to run off the SureSine 300, but for higher output inverters, or on grid operation, a standard 88 - 108 MFD will work wonders. BTW, the compressor model for these start capacitor values is: ASF51U6. The manufacturer may not be using the same compressor in all of these freezers, and different compressors may require a different value capacitor if you decide to do any modifications. As I've mentioned in other posts, converting to run off the SureSine 300 requires additional modifications to the starter, including the use of an autotransformer, or a regular 120 to 12 volt transformer rated roughly 100 VA and wired as an autotransformer, and relays to engage it during the start sequence. But that's not something for anyone not really familiar with electronics etc to attempt.
My main thing here, is to show the amazingly low (to me at least) power consumption of what is now an 8 cu ft fridge. 120 watt hours for a 12 hour period. That's an average of just 10 watts continuous! My satellite receiver uses more than that!
I'm on the run, so that's it for now.
Wayne

[niel]

that sounds real good wayne. inform us further on this in this thread so we don't have to jump around.

i'm curious if you measured its consumption before conversion so we have and idea of the leap it made from one to the other.

[Volvo Farmer]

I want to know how you deal with condensation. To get a nice 36 degree temperature, the evaporator surely has to get down below freezing for a short period of time. The humidity in the box must be freezing on the coils, melting off, and running down the walls several times a day. Isn't there a puddle of water in the bottom after a period of time?

Nice write up! I would be very interested in seeing long term (weeks?) KwHr numbers along with a notation of ambient temperatures.

[wrdaigle]

I have a 12cf chest freezer conversion. We definitely get condensation. I end up sponging it out about once a month, so it hasn't really been a problem.

[wrdaigle]

Wayne, is your latest an upright? I couldn't find any info on the model number you listed. I will be curious to see what your numbers are like over time. Our chest freeze conversion runs about 300 and change per day. I didn't think there was a chance of achieving this with an upright. Keep us posted.

[SolaRevolution]

Hmm. This seems like it would be way more cost efficient than a propane fridge even if you had to run a generator to recharge the batteries. Any idea how those numbers might compare?

I'm thinking about a battery system charged only from a generator which powers a household, not one that only runs a fridge.

-Alex

[BB.]

It can be done...

In Africa (and elsewhere, I am suer), there have been "hybrid" generator installations. During "off hours" (night, mornings), the generator is off and a battery bank + inverters supplies the loads. During evening when there are lots of loads (cooking, lighting, etc.), they fire up the genset and run the loads, plus recharge the battery bank.

It really depends on your loads... If they are highly variable (mostly low with fridge/freezer during the day, and heavy loads in evening--cooking/washing/lighting/tv/computers/etc.), then a hybrid system may make a lot of sense.

However, if your loads are steady (or heavy loads are more than 8-12 hours at a time), running a genset may make more sense (savings on battery banks + inverters + loses from charging battery bank, charge controllers, inverters vs fuel costs).

Obviously, if you have solar panels in the mix--that changes the whole generator/fuel cost issues.

From what I have seen, you almost have to make a model of your system (energy use, times, fuel usage/costs, battery replacement costs, etc.) and design several paper systems and see what shakes out.

Even the amount of power used makes an issue in the gasoline vs diesel choices (there seem to be very few choices for less than 8-10kW power diesel gensets vs the 1-2kW gasoline inverter/generators out there).

If your power use is low, and variable (weekend 2-3 season use vs 3+ season/full time occupation), the whole small genset, propane fridge, 100% solar solutions tend to favor a small 1-2kW genset and a battery bank + inverter/genset + a few solar panels for "quite time" power plus propane fridge.

If you are 9+ months of the year with full time occupation, then solar+battery+inverter make good sense for an electrical fridge (plus backup genset).

-Bill

[waynefromnscanada]

Hi again. Some answers to you're questions. Yes, I plan on keeping this thread updated for some time, updating those interested, as I gain experience with this one.
This, as was the last one, an upright. Here is a link to this model: http://www.sears.ca/product/kenmore-...26-461_3_99192
Re condensation: The chest freezer I converted did indeed have a condensation problem, and had to occasionally be sopped out. With my first upright, I kept the temp just above freezing, as I'm doing with this one, and believe it or not, had no condensation problem at all. How can that be you ask? Well it was a surprise to me too. Running the "fridge" that close to freezing results in all the condensation freezing on the bottom of the shelf nearest the top that I can place items on. This is the first shelf to col, and when used as a fridge, is the coldest of them all. There is one final "coil" on the ceiling, but it appears to be the last to cool, thus no ice there. I just now checked this one and sure enough, a bit of ice is appearing on the under side of the upper shelf. How did I handle that with the former one? When it needed to be "defrosted" I'd place a large, thick towel over the items directly under the iced up shelf, shut off the power, leave the door shut and wait 4 to 6 hours for the ice to melt, after which I just removed the now wet towel and turn the "fridge back on. How often? Depends on the time of year and how often the door is opened, or left ajar by accident. During winter, when the air is quite dry, I could easily go for a couple or more months. Summer is different with it's higher humidity, and I usually had to do it every 3 wks or so. Way more often if something interfered with the door completely closing and my not noticing it.
One really, really important thing I've found about running the temp so close to freezing, is that totally unlike a regular fridge, food items last at least 4 times longer. Vegies etc, yes, even bread if I put it in there. That was a real eye opener for me. And if you want an ice cold drink of milk, an ice cold drink is what you get! Again, totally unlike a regular fridge, that will provide you with a cool drink. For these reasons alone, I'd never be happy with a regular fridge again.
Re it's power consumption as a freezer, I haven't tried that of course, but the "certified" Energy Star rating is 328 kwh/year, (0.9 Kw/day) Again, when operated as a freezer.
Just checked the Kill-A-Watt, and having run for 18.5 hours, it's showing 0.22 kwh, and the compressor has just shut off, so won't be going again for almost an hour, thus the average should be a bit less than the presently indicated average of 12.2 watts.If this holds, consumption will be less than 0.3 Kw/day. In fact, if I desensitize the thermostat further, so there are fewer starts, thus less time running at higher consumption, I can see this improving.
Again I ask - - if I can convert a far better insulated freezer into a super efficient fridge, why, why, why doesn't a manufacturer make a real fridge this efficient? Are they being bribed by Big Energy to drag their heals?
That's it for now. Will be glad to answer any questions I can. Share the wealth of knowledge as we continue learning.

[Blackcherry04]

Off cycle-defrost refrigerators used to be everywhere in the 60's , but as people became lazy they disappeared from the market. The only ones I ever saw were uprights and had a non-defrosting freezer on the top. They had a second coil on the refrigerator compartment that had a perimeter pan and would defrost every cycle.

I also remember that one company ( Kelvinator ), I think, made a heat pump model the would defrost on the run and sounded like a freight train with a reversing valve.

[vtmaps]

One really, really important thing I've found about running the temp so close to freezing, is that totally unlike a regular fridge, food items last at least 4 times longer. Vegies etc, yes, even bread if I put it in there. That was a real eye opener for me.

That is also my experience. My fridge is a real fridge-freezer (not a converted freezer), but I have just turned the thermostat a bit lower and keep the temp in the fridge section near freezing. It consumes about 400 wattHours per day. --vtMaps