Yacht Fridge VS Residential Fridge

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Yacht Fridge VS Residential Fridge

May 26, 2016, 09:59:37 am

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.

Re: Yacht Fridge VS Residential Fridge

Reply #1 – May 26, 2016, 10:14:15 am

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.

Re: Yacht Fridge VS Residential Fridge

Reply #2 – May 26, 2016, 10:32:46 am

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.

Re: Yacht Fridge VS Residential Fridge

Reply #3 – May 26, 2016, 10:43:12 am

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.

Re: Yacht Fridge VS Residential Fridge

Reply #4 – May 26, 2016, 12:04:22 pm

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.

Re: Yacht Fridge VS Residential Fridge

Reply #5 – May 26, 2016, 12:51:02 pm

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?

Re: Yacht Fridge VS Residential Fridge

Reply #6 – May 26, 2016, 01:09:15 pm

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.

Re: Yacht Fridge VS Residential Fridge

Reply #7 – May 26, 2016, 02:19:55 pm

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.

Re: Yacht Fridge VS Residential Fridge

Reply #8 – May 26, 2016, 02:42:19 pm

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.

Re: Yacht Fridge VS Residential Fridge

Reply #9 – May 26, 2016, 02:50:31 pm

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.

Re: Yacht Fridge VS Residential Fridge

Reply #10 – May 26, 2016, 02:54:59 pm

Quote from: Roger & Susan in Home2 – May 26, 2016, 11:10:17 am

Ours has "twin cooling" meaning it has two condensors, one for the refrig and one for the freezer.

It is easy to figure out what your refrigerator choice migh need for power. Look at the energy guide label. (An example is shown). Take the KWhrs x 1000, divide by 365 days, divide by 24 hrs. This gets average watts per hour. Divide by 12 to get average amp load on the batteries assuming 100% efficiency. Add 10-20% for the inefficiency of the inverter.

594x1000 / 365 / 24 = 67.8
67.8 / 12 = 5.7 x 1.2 = 6.8 amps average battery load.

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.

Re: Yacht Fridge VS Residential Fridge

Reply #11 – May 26, 2016, 03:00:03 pm

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...

Re: Yacht Fridge VS Residential Fridge

Reply #12 – May 26, 2016, 03:20:59 pm

Quote from: prfleming – May 26, 2016, 03:00:03 pm

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

Re: Yacht Fridge VS Residential Fridge

Reply #13 – May 26, 2016, 03:59:34 pm

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

Re: Yacht Fridge VS Residential Fridge

Reply #14 – May 26, 2016, 04:31:14 pm

Quote from: Roger & Susan in Home2 – May 26, 2016, 04:08:54 pm

I don't see an defrost on/off but there is an energy saver setting. Even though I think it says an annual average usage of about 60 watts it seems like it uses more than that.

Time to get the meters out.

Jim C.'s 6 8Ds have about 750 amp hrs to 50%. 16% of that (84% left) is about 145 watts per hr for 10 hrs. Samsung says 22 cuft refrigerators are around 700 KWhrs per yr or on average 80 watts. The inverter is probably eating the rest at a 5 amp idle load. Lots of other stuff on all the time as well. I think I did the math right.

All of this energy stuff is interesting but you will be very hard pressed to find anyone who has done the switch to either a marine type or residential refrigerator who wants to go back. We don't have any problem staying anywhere over night on the inverter. In the middle of the winter heading south when it is cold and the Aqua Hot is on and night starts at 4:30 and it is not light until almost 8 we will run the Gen in the AM for coffee and toast.

Power management changes a bit. That is why I want to add 2 more 8Ds and a very high efficiency pure sine wave inverter just for the refrigerator. (Separates the age cycles in the battery banks as well). And a smaller pure sine wave inverter just for the TV etc. then I can shut off the big inverter and it's high idle load. There are other strategies towards this goal as well.

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.

Re: Yacht Fridge VS Residential Fridge

Reply #15 – May 26, 2016, 04:43:26 pm

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.

Re: Yacht Fridge VS Residential Fridge

Reply #16 – May 26, 2016, 05:16:11 pm

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...

Re: Yacht Fridge VS Residential Fridge

Reply #17 – May 26, 2016, 05:17:30 pm

It appears my marine refrigerator using at most 48 Watts (12 volts only) per running compressor is an energy miser.

Re: Yacht Fridge VS Residential Fridge

Reply #18 – May 26, 2016, 05:33:08 pm

Roger I just saw your question:

Quote from: Roger & Susan in Home2 – May 26, 2016, 12:51:02 pm

30 amps is 360 watts, quite a bit. Is that steady state?

Yes, the old Dometic 120V heating element draws about 325 watts. It runs pretty much continuously, the fridge is getting old...

Re: Yacht Fridge VS Residential Fridge

Reply #19 – May 26, 2016, 05:38:09 pm

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!

Re: Yacht Fridge VS Residential Fridge

Reply #20 – May 26, 2016, 05:43:40 pm

All I know is, it keeps our pizza and apple beer cold, so life is good!

Re: Yacht Fridge VS Residential Fridge

Reply #21 – May 26, 2016, 10:19:43 pm

So are marine fridges more efficient overall? and if so how much more so? Obviously initial investment is greater.

Re: Yacht Fridge VS Residential Fridge

Reply #22 – May 26, 2016, 10:53:03 pm

Quote from: TAS69 – May 26, 2016, 10:19:43 pm

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.

Quote from: Roger & Susan in Home2 – May 26, 2016, 10:35:11 pm

It sounds like the marine refrigerators us about 48 watts. And the 19 cu ft Samsungs us (nominally) 60 watts.

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.

Re: Yacht Fridge VS Residential Fridge

Reply #23 – May 26, 2016, 11:30:11 pm

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

Re: Yacht Fridge VS Residential Fridge

Reply #24 – May 26, 2016, 11:55:29 pm

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!

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