I see the thread about yacht type refers, and as I am considering installing a residential type in my FT..... What (besides the 12V operation) are the pluses and minuses of either ? I have had a boat, yet didn't think of using that type of refer. I have a feeling that the yacht type MAY be better constructed to handle the motion? Looks like a good alternative to me.
We considered RV, Marine and Residential refers when the decision needed to be made and went with a residential basically for monetary reasons. After we sold our Dometic 1492 for about $350.00 our new refer cost less than 1 coach buck installed. 18 cf Samsung, French door, 33". To date we feel we made the right decision for us. Self install with Fofum help.
Lots of threads on this topic if you were to use the search button. Many pros and cons every way you slice it for any option you might investigate.
Like some one here said. Do what makes you happy. ;D
The yacht type refrigerators generally have 12 volt compressors, usually one for the refrigerator and one for the freezer. Some can run off 110v when it is available. They are well made, well insulated and pretty efficient. We had a smaller one in our last RV that served us very well. They are more expensive than a residential refrigerator.
We switched to a Samsung Residential refrigerator from the Dometic in our FT. We did the install ourselves, many here have done it as well. LIke Scott, our net cost was less than $1000. At 15 years old we were concerned about the fire risk, maybe low but we saw three coaches in one summer burned to the ground from refrigerator fires. Good maintenance, cleaning and inspections reduces that risk. The other big reason was space. We definitely wanted more freezer room and some more refrigerator room. Time to cool in the Samsung is a couple hours, 24-36 hrs in the Dometic. The Samsung stays colder and temps are much more consistent. We chose a 32" wide countertop depth ~19 cu ft model. This gave us a narrow cabinet to one side that we have found to be extremely useful, much more so than the space lost under the Dometic.
Somone else can let you know what power requirements are for the yacht type refrigerators. Our Samsung, with the ice maker on has an average load on the batteries of less than 5 amps (less than 60 watts). With the ice maker off it is less. Warm start up loads with the ice maker on are much more. If you are usually plugged in then no problem. If you are an extended boondocker than it does add load to your power systems. Many with solar would easily cover that. A bit more gen time covers it for the rest of us. You can recover some of that by switching to all LED lighting.
The yacht type refrigerators are quiet. The residential refrigerators make a bit more noise. I noticed at first compared to the Dometic but then is just becomes ambient noise. Some res refrigerators make much more noise. One of the reasons we chose the Samsung was for its low noise level.
This size Samsung is the most commonly installed (we have heard) residential refrigerator installed in RVs. We told the dealer exactly what we were going to do with it and they said it had no impact on the warranty. We bought a 5 year extended warranty for it and it was about 10% of the price. Fix or replace. Comfort.
All in, one of the best upgrades we have done.
The Samsung I installed in my sob has twin condensors and only draws 3 amps. I installed it in 2012 so probably the model number would be out of date. It is a 18 cu.ft. with icemaker. My installation was made easier as the coach had Aqua-Hot and there was unused space below the Norcold for a propane heater.
Roger,
Have you ever measured the inverter draw with your clamp meter? It would be interesting to know what the actual current draw is (including inverter efficiency) with the fridge running at max cooling. This additional load would be what your alternator would need to handle while driving.
My original fridge draws approx 30 amps on the inverter going down the road - less efficient than a new fridge for sure.
I will try that. Good idea. The inverter on powering nothing draws several amps.
30 amps is 360 watts, quite a bit. Is that steady state?
Not always possible, but before installing your fridge, try to put a switch in the auto defrost circuit so you can defeat it when dry camping. My 22 cf samsung will draw 6 new 8d's down to 84% [by trimetric] in about 10 hours at night. Appears defrost circuit draws about 150 watts when in use.
I too have a new Samsung 17.9, 33" wide, I installed myself 3/15, with the help of some friends with muscles! My old unit had sprung a leak, and I happened to catch one day when I happened to take off the access panel.
It has been perfect for our use, which is pole to pole camping, using first the modified sine, and now the new upgraded pure sine inverters. I have forgotten to turn on the inverter a few times and the recording thermometer senders in the refer, and freezer drawer has only shown a few degree rise during those travel times.
After 14 months, full time, 15K, and 28 states, we have enjoyed perfectly requested temps in both parts of the big box, and drawer.
I reported on this almost two years ago, when I had my OEM refrigerator replaced as an insurance claim due to a fire. I went with a custom-made Sea Freeze unit of the same dimensions as the OEM refrigerator. It uses two compressors, one each for the refrigerator and the freezer. They run on 12 volts only.
The latch assembly is commercial grade. No way it will ever open by accident.
I believe power used is less than residential refrigerators, under 4 Amps per compressor (at 12 volts), or 48 Watts. Much less when the compressors are not running, but the inside the refrigerator fan always runs.
My only issue, and a small one at that, is that the refrigerator box needs to be defrosted after two or three months or the temperature starts rising. The freezer has been fine. (Not being self-defrosting, the freezer is a deep freeze, and I can set it as low as I want, Usually just below zero)
When I need to defrost the refrigerator, I completely empty it and place non perishables on the counter, perishables in a cooler bag with some blue ice from the freezer, turn off the refrigerator section only, open the door with a fan blowing, and wait until the walls feel warm and dripping stops. This takes about an hour. Then I turn it back on and close the door, and watch my remote thermometer. In another hour, the temp is back to 40 or below and I put everything back.
Peter, my Samsung specs say max draw is 6 amps at 120v, 720 watts or probably 70 amp battery load through the inverter. This is a warm start with ice maker on. We generally start up while plugged in.
My understanding of the Twin Cooling system is that it has two evaporators and a single compressor.
Amended my post I thought twin cooling systems also meant two compressors. Don't see any power saving with two condensers as the compressor would have to come on for either the fridge or the freezer when temp rises.
Roger, max draw might be the compressor surge at start, not sure. When you measure it - will be interesting. Did you switch your defrost heater - I wonder if that is a constant draw all the time...
By watching my current draw, it appears my fridge uses some type of timer or thermostat to turn on defrost heater. Did not log any on/off times, but several times have noticed an extra 150 watts or so being used by the fridge over the normal draw when compressor is running.How the Defrost System on your Refrigerator Works (http://www.applianceoutletservice.com/appliance-care-tips/refrigerator-tips/refrigerator-defrost-system-information.htm)
In HVAC scroll compressors (not sure what a residential refrigerator has, but Scrolls are pretty efficient) the LRA (locked rotor or start up amps) are usually in the range of 4-6 times the RLA (run load amps). The start event has a duration of about 300 milliseconds. LRA and RLA are usually listed on the sticker on the condensing unit.
I haven't seen a lot of published LRA and RLA specs for refrigerators. Also residential refrigerators in an RV probably don't run that many hours a day.
My Haier residential unit doesn't even have a specification for amperage draw that I can find anywhere in the documentation
The math is pretty close, have not tried with this fridge, but have tried several 1000 watt psw inverters on a small chest freezer I have, and both tripped out on overload when compressor starts. No problems with 2000 psw inverters.
I am glad my math is close. I have a Magnum 1000 watt PSW inverter. The refrig runs on it nicely. I have not tried a warm start on inverter though. The Magnum has quite a big surge capacity but I don't have the book here to say what it is.
Chuck:
Great test, thanks for the quick info! Looks like your fridge runs at about 175 watts (12.5 volts x 14 amps). This is about 1/2 what my old Dometic draws now. Just planning ahead, this will free up some alternator capacity to run my front roof A/C on the inverter. Yea...
It appears my marine refrigerator using at most 48 Watts (12 volts only) per running compressor is an energy miser.
Roger I just saw your question:
Yes, the old Dometic 120V heating element draws about 325 watts. It runs pretty much continuously, the fridge is getting old...
Chuck:
(Forgot to subtract out the inverter baseline draw).
Looks like your fridge runs at about 110 watts (12.5 volts x (14 - 5.2)=8.8 amps). Much better!
All I know is, it keeps our pizza and apple beer cold, so life is good! ^.^d
So are marine fridges more efficient overall? and if so how much more so? Obviously initial investment is greater.
Tom:
I'm kind of new to this whole fridge upgrade thing, but what I see so far is the 2 types of refrigerators are probably close in actual "efficiency" (power used to cool the cubic feet that you have), the big difference is the marine fridges have 12 V compressors, which eliminates the requirement of inverting 12 V to 120 V for the residential fridges, which adds inverter power losses to the power consumption and the cost of the inverter if you go with a dedicated inverter. Also, the residential option offers the choice of substantially more cubic feet if you have the room.
Roger:
I looked up the Vitrifrigo DP2600 on Bay Marine Supply and the rated power consumption is 65 watts, so pretty comparable to your Samsung.
This is a fascinating read. I am considering putting in a residential refrigerator. I spent yesterday in Nacogdoches with MOT and FOT looking at options and settled on the Samsung RF18 being described. Our rig seems fairly stock w/two gel cels, Xantrex and a 10Kw Kubota driven (factory) PL set.
One opinion included a automatic generator start device. The other team felt I could go with no problem without the AGS add-on.
Any thoughts about my choices? We are using the coach regularly and the gen set, too. We use shore power about half time on a trip. I hope my high jacking of the thread will be forgiven if I include the words, "yacht refrigerator." Great information. Thanks. P
Paul,
You are not high jacking at all - your question fits right into the discussion of fridges, inverters, power management, etc.
When we had our Magnum MS2812 installed, we were offered the option of Auto Generator Start. We declined, because the way we use our coach, I could not think of a situation where it would be needed. With the Magnum inverters, you can always add the function at a later date if the need arises. Your Xantrex may offer a similar optional package. If so, you could defer the decision until you gain some experience operating your new equipment without it.
I hope the members who have AGS and have actually found it useful, or better yet essential will speak up. I am sure there are times when it would be a great feature - we personally just haven't run into those particular conditions....yet. Knock on wood!
From Peter..."I looked up the Vitrifrigo DP2600 on Bay Marine Supply and the rated power consumption is 65 watts..." And at 8.1 cu ft is is smaller than the Dometic we had and less than 1/2 of the size of the Samsung.
When we had our coach inspected they said the AGS did not work, but it does. If I am concerned about power I turn it on when we go to bed. Sometimes it will start at six AM or so. Often it does not.
Paul the auto gen start is nice. If you,are normally at places where you are plugged in then the res refrig is a great addition. You do need to watch power levels. A really good power monitoring system (apoer in and out and state of charge) is worth investing in as well.
Not many answers to the original question. Some good info I'm sure for some though.
Original question ....
"Not many answers to the original question. Some good info I'm sure for some though."
Residential Refrigerators use more power than an LP refrgierator. Just a little bit more than a marine refrig. Most Residential refrigerators are much bigger than Marine refrigerators. Residential refrigerators weigh 1/2 of what the LP refrigerator weighs. Either of these have almost no chance of a fire. Residential refrigerators have been used in coaches for a long time. Buy an extended warranty if you are worried. Residential refrigerators are about 1/2 to cost or less of a marine refrigerator.
Either is a great choice. Your needs for space, price, power will make the decision for you.
All of this has been in earlier posts, what other questions do you have?
I have mentioned before Foretravel put a residential refrigerator in my 1981 from the factory. I used it for 18 years with no problems. They have been in motorhomes for a very long time.
Dave,
You asked for the "...pluses and minuses..." of both type fridges. Seems, to me, like you have gotten many excellent answers to your question. There are more replies pertaining to residential models, because there are more of them in service. Those with the marine type units have tried to point out the differences, and advantages of that choice. If you are looking for a direct, side-by-side comparison, I don't think you will find it here. But you should now have a good understanding of
why some members picked one type over the other. Like so many other things, it will ultimately be a personal choice based on your unique needs and wants (and the size of your discretionary fund).
The residential model is popular, simply because it works so well. Depending on your handy man skills, it can also be relatively inexpensive. With so many units already successfully surviving in RVs, I don't think questions of reliability should trouble you.
If you are a "Tekkie", then the marine type technology might call to you. Several members are reporting total satisfaction with these models, so once again it appears to be a safe choice. Pure 12 volt power seems, to me, much more logical if you intend to spend a lot of time dry camping. Without a shore connection, battery conservation assumes greater importance. Why run 12 volt through a expensive inverter simply to power a fridge, when you can just as easily power the fridge directly off the battery?
Bottom line: both types of fridge keep stuff cold, so just pick the one that works for you.
Not related to the exact question posted but the heart interface manual mentions running the batteries between 50% to 90% as the gen run time is prohibitively expensive and noisy for most to get from 90% to 100%.
For the longer cycle life I opted for mk gels.
I think the agms are ten percent roughly higher capacity than the gels with a bit less low temp power and 1/2 the cycle life.
As the batteries age the extra initial capacity should match the gels in a few years?
The gels would seem to be able to stay closer to their new specs in hard use for longer.
Mk's engineer mentioned the latest gels might have double the cycle life shown.
Minimum of four 8d's and/or a lot of solar for any electric refer.
And a more effecient inverter?
Original systems were not designed for this much draw and to be able to dry camp for a few days on internal capacities without running the gen.
All changes with double the electrical draw.
Unless like a lot you do not mind the gen or camp pole to pole.
I went out and clamped a DC clamp-on Amp meter onto the wires going to my two compressors. This is a custom built Sea Freeze unit with a compressor for the refrigerator and a compressor for the freezer.
The refrigerator compressor was running at the time, drawing 4.5A, nominally 54 Watts at 12 Volts. This would be double had both compressors been running. I don't know the duty cycles, but the freezer compressor rarely runs and the refrigerator compressor fairly often runs.
I believe this compares favorably with a residential refrigerator, even with a very efficient inverter.
Thanks Tom, I have been using 12.5 volts as a nominal, more in the typlcal voltage range. Do you have a battery monitor system like a Victron or one like it. With the batteries charged and not other power input and "everything" off including the refrigerator (but cold) it will tell you the voltage and the amp-hrs pulled from the battery. Turn on just the refrigerator and nothing else. Come back several hours later, maybe a day and see how many amp-hrs have been pulled. The difference gives you a pretty good idea of the average power consumption over time. Exactly what we need to make a good marine refrig to Residential refrig comparison.
We need someone to do the same with an Lp refrig at steady state to see what 12v power it uses.
Duty cycle is important. I can see very small differences in power usage during the day compared to overnight when it is cooler.