Replacing fridge with thermoelectric cooler

[The Eyesore]

Our Dometic RM2310 just died. Waaah!! We're going on a two-week trip in October. I'm thinking of replacing it with a thermoelectric cooler. I don't want the noise of a compressor and don't want the expense of another absorption fridge (although I did love ours before it died).

Looking at this one:
https://www.amazon.com/Koolatron-P27.../dp/B0001MQ7DQ

It seems it will fit into the void of the dometic after I pull it out, and it's operable upright, so the door will swing out like a fridge. Any suggestions or opinions welcome.

[jrobe]

Read the 20% 1 star reviews on that cooler and then decide if that is really what you want. You can't even put ice in there in the upright position which may be how it works the best.

I have no idea what the concern is about the "noise of a compressor refrigerator." Ours is very quiet, keeps food perfectly cold and takes very little battery power. It is close to perfect for our RV.

[avanti]

Peltier devices are significantly less energy efficient than compressor units--more so as the heating load increases. If this matters to you, it wouldn't be a great choice as a permanent solution. They are nice and quiet, though.

[RT-NY]

Originally Posted by The Eyesore

Our Dometic RM2310 just died. Waaah!! We're going on a two-week trip in October. I'm thinking of replacing it with a thermoelectric cooler. I don't want the noise of a compressor...

Originally Posted by jrobe

I have no idea what the concern is about the "noise of a compressor refrigerator." Ours is very quiet, keeps food perfectly cold and takes very little battery power.

I agree with the OP about the noise of a compresser -- so much so that I am surprised that I have never seen it come up before in discussions about compressor vs. absorption. This is a matter of personal sensitivity, of course, but I often find the humming of a fridge in an RV very annoying.

And for me the 60+ amps a day that even the best compressors require is not "very little battery power."

So a 3-way fridge will always work better for me even given its limitations, but there is no "right answer" on this question -- it all depends on what you like and what you need.

In any case, I would not be surprised if the thermoelectric cooler is not very satisfactory and it seems to require as much power as a compressor.

[booster]

Originally Posted by RT-NY

I agree with the OP about the noise of a compresser -- so much so that I am surprised that I have never seen it come up before in discussions about compressor vs. absorption. This is a matter of personal sensitivity, of course, but I often find the humming of a fridge in an RV very annoying.

And for me the 60+ amps a day that even the best compressors require is not "very little battery power."

So a 3-way fridge will always work better for me even given its limitations, but there is no "right answer" on this question -- it all depends on what you like and what you need.

In any case, I would not be surprised if the thermoelectric cooler is not very satisfactory and it seems to require as much power as a compressor.

60 amp hours a day is on the high end for most 3cf or so compressor frigs. We run closer to 25-30 in moderate weather and would only get near 60ah per day in over 100* weather. A compressor frig of the size of the one the OP listed would use well under our use, especially is it was on a slide to get out food instead of facing horizontally.


Some have mentioned loudness for compressor frigs, but most are not bothered. Much quieter than the ceiling fan for instance or a circulating fan in the van, but to each their own.


The biggest issue with the OP listed on would be the 40* under ambient best case cooling which really isn't good enough for most of us.

[RT-NY]

Originally Posted by booster

60 amp hours a day is on the high end for most 3cf or so compressor frigs. We run closer to 25-30 in moderate weather and would only get near 60ah per day in over 100* weather. A compressor frig of the size of the one the OP listed would use well under our use, especially is it was on a slide to get out food instead of facing horizontally.

You are saying that a compressor fridge in moderate summer weather can run for 24 hours consuming only 25 amps? I do not know from personal experience, but my impression from what I have read, including on this forum, was that most people require more power than that. I am curious what other forum members experience with their compressors over 24 hours in, say, average summer days with 80 degree high temps?

[booster]

Originally Posted by RT-NY

You are saying that a compressor fridge in moderate summer weather can run for 24 hours consuming only 25 amps? I do not know from personal experience, but my impression from what I have read, including on this forum, was that most people require more power than that. I am curious what other forum members experience with their compressors over 24 hours in, say, average summer days with 80 degree high temps?

Yes we can, and do run lower than the 60 in 80*. Depending on humidity and how often we open the frig. Ours is an 85L, 3.1cf isotherm.

I have a thread on the initial setup and testing of it get the good performance we have achieved. It took a bit of work to get to the sweet spot as Isotherm had made some not all the great changes to unit compared to our previous frig of the same model.

We do see others that run higher than we do and that could be installation variations, insulating around the frig, etc or what temp the run frig at, plus use patterns. I would 60ah per day on the higher end of most users.

[GeorgeRa]

Originally Posted by booster

Yes we can, and do run lower than the 60 in 80*. Depending on humidity and how often we open the frig. Ours is an 85L, 3.1cf isotherm.

I have a thread on the initial setup and testing of it get the good performance we have achieved. It took a bit of work to get to the sweet spot as Isotherm had made some not all the great changes to unit compared to our previous frig of the same model.

We do see others that run higher than we do and that could be installation variations, insulating around the frig, etc or what temp the run frig at, plus use patterns. I would 60ah per day on the higher end of most users.

I have the same fridge, Isotherm 3.1 CF and the same energy usage.

Following your point mine also uses energy measured in amphours not amps, amps are units for current not energy, for example a car speed is measured in miles/hour not in gallons of gas.

It has to be very quiet to be able to hear the fridge.

[booster]

For reference on energy use on compressor frig.


https://www.classbforum.com/forums/f...lts-12476.html


and


https://www.classbforum.com/forums/f...lts-12869.html

[RT-NY]

Originally Posted by GeorgeRa

I have the same fridge, Isotherm 3.1 CF and the same energy usage.

Following your point mine also uses energy measured in amphours not amps, amps are units for current not energy.

Yes, of course, ah not amps - but the actual question remains: what is "the same energy usage" that you experience on average summer usage: 25ah for 24 hours?

Or, more to the point, what kind of energy budget should an average user of a compresser plan for for a 24 hour period. Is 60ah really that far off as a rule of thumb for most people?

[GeorgeRa]

Originally Posted by RT-NY

Yes, of course, ah not amps - but the actual question remains: what is "the same energy usage" that you experience on average summer usage: 25ah for 24 hours?

Or, more to the point, what kind of energy budget should an average user of a compresser plan for for a 24 hour period. Is 60ah really that far off as a rule of thumb for most people?

Energy usage depends on fridge size, van insulation, ambient temperature, type of compressor, 1 or 2 compressors, and fridge manufacturer. I can only reference to my Isotherm/Danfoss fridge. I had a similar size compressor fridge on the boat but it was not near as efficient as my Isotherm but it was not an expensive fridge, not Danfoss.

[booster]

Originally Posted by RT-NY

Yes, of course, ah not amps - but the actual question remains: what is "the same energy usage" that you experience on average summer usage: 25ah for 24 hours?

Or, more to the point, what kind of energy budget should an average user of a compresser plan for for a 24 hour period. Is 60ah really that far off as a rule of thumb for most people?

Our testing in the linked threads shows actual numbers and conditions.

As mentioned, it all depends on the frig size and quality of the installation on top of the frig brand and model. 60ah per day may fit some, others could easily target 30-40 overall average in moderate to warm temps. We have used 40ah per day for all the time we have had compressor frigs but it really is only been used for sizing battery banks and/or days with crummy solar conditions. We now have much more battery bank than we did in the beginning so no longer any need to even check it during use except as a curiosity.

We did such curiosity testing recently just to see if the oft quoted "no need for solar" was really that cut and dried with a big battery bank and big alternator when running a compressor frig. We run the lithium bank between 35 and 80% SOC for charge and discharge range and don't want solar to be putting on charge voltage when at 85% as it isn't capable of turning itself off there. I turned in on at about 40-50% SOC on trips this year. We never had to charge off the alternator over a total of about 3.5 weeks over two trips once the solar was on. It is 300 watts so not huge bank. We never really lost SOC on average over the time as we didn't have many days in a row of bad solar. We were not returning on solar on average over about 50ah per day and that covered all our usage so frig use was probably around 30ah per day.

For us 60ah per day would be pretty large amounts over estimating.

We have run our frig on 2 golf cart wet batteries in the past and even with 3 days in a row of bad sun still were OK with no driving for charging.


The OP could be looking at as high as over 90ah per day if the frig listed ran 24/7 cooling and compressor frig would be way less than that.