Replacing Fridge with a residential and/or high efficiency electric?

Topic: Replacing Fridge with a residential and/or high efficiency electric? (Read 2089 times) previous topic - next topic

Replacing Fridge with a residential and/or high efficiency electric?

February 08, 2015, 03:13:16 pm

Has anyone done any research on energy efficient residential and/or marine electric solutions to replace a Dometic Elec/Propane unit? The existing one is still functioning, but it's getting a bit ragged and we have to replace the passenget side windshield anyway. ;-) Trying to get a bead on what kind of power budget an efficient all electric solution might take. The alternative is to get a new RV specific elec/propane unit probably another dometic unless there are better options out there? Anyone know any good resources?

Thanks in advance for any feedback/suggestions.

James and Susan

Re: Replacing Fridge with a residential and/or high efficiency electric?

Reply #1 – February 08, 2015, 03:24:25 pm

Wow, a ton of threads on this topic. Suggest using search function on FOFUm - you will get a lot more input that way Then come back with any unique and interesting questions

Re: Replacing Fridge with a residential and/or high efficiency electric?

Reply #2 – February 08, 2015, 03:56:49 pm

Fair enough. :-)

Connection is REALLY spotty driving through mountains in VA/TN so I figured I'd get the initial thread/topic out there. I'll do some digging around tonight after we get into the campground and hooked up to the wifi and/or cellular signal is a bit more stable.

James

Re: Replacing Fridge with a residential and/or high efficiency electric?

Reply #3 – February 08, 2015, 05:33:48 pm

Quote from: Tim Fiedler – February 08, 2015, 03:24:25 pm

Wow, a ton of threads on this topic. Suggest using search function on FOFUm

What Tim said.

Re: Replacing Fridge with a residential and/or high efficiency electric?

Reply #4 – February 08, 2015, 06:32:18 pm

Jerry just replaced his fridge with a helium RV fridge in their 1993 U300/36 (exactly like ours with same floorplan). They are available at PPL for very reasonable prices. He reports excellent cooling. Gets rid of the ammonia fire danger.

Pierce

Re: Replacing Fridge with a residential and/or high efficiency electric?

Reply #5 – February 09, 2015, 12:25:00 am

Thanks for the timely and useful words of warning! :-)

I think I'm leaning more and more to replacing the fridge (and that was BEFORE starting to think about the fire risk!), but the question is whether to go with a new helium unit, a much bigger residential unit, or a smaller residential unit and recoup a lot of storage space in the kitchen?

I think making some of those decisions are outside of my purview, I'll just be providing technical advice on feasibility. ;-)

James

Re: Replacing Fridge with a residential and/or high efficiency electric?

Reply #6 – February 09, 2015, 12:52:24 am

search function will also show some choices in the "Danfoss" and custom built categories

Things to think about FIRST.

Full Time or part time?
Close to stores or out in Boonies?
Connected to shore power or boon dock a lot?
Hate running Generator or don't care, that is why I have one?
Solar on roof or not?
Do you have Aquahot? If so consider losing refrigerator and gas burners - replace with Residential and induction cook tops - remove Propane completely and add batteries or storage.
And of course, most important (actually, you already know, the only thing that matters - what does DW want? - advice, don't let her see a great residential install.....)

All these topics well vetted already - "search" will keep you busy reading for quite a few nights!

Good luck in the decision

24" deep 33" wide hair french door residential - cause it was cheap and it fit - we love it!!! 8 hours labor to remove sold unit, modify cabinet and install new unit - Parliament motor coach, St. Pete FL.

Re: Replacing Fridge with a residential and/or high efficiency electric?

Reply #7 – February 09, 2015, 01:22:26 am

Quote from: Pierce & Gaylie Stewart – February 08, 2015, 06:32:18 pm

Jerry just replaced his fridge with a helium RV fridge in their 1993 U300/36 (exactly like ours with same floorplan). They are available at PPL for very reasonable prices. He reports excellent cooling. Gets rid of the ammonia fire danger.

Pierce

James,

Just recently installed an Atwood helium 8 cu ft gas/electric fridge from RV Parts Country. It is a left hand model with an optional fan on the back for ventilation. Atwood Helium RV Refrigerator 8 Cubic Ft. I was surprised like Neal Pilsbury was after his installation as to how quickly it cooled down to operating temps. In about 2 &1/2 hours it was already -3 in the freezer and 38 degrees in the fridge section.

I also covered the inside of the compartment with Hardie backer board for extra fire protection as pioneered by Pierce. It's easy to do, inexpensive, and an excellent heat barrier if needed.

My old fridge was working fine when the dreaded ammonia smell happened. When I took the baffle off you could see all the rust. If your fridge is over 10 years old chances are there is rust back there you can't see.

No ice-maker with the new fridge but I gained about 2 cu. ft of storage. I'll post more pics when I get finished.

Jerry

Re: Replacing Fridge with a residential and/or high efficiency electric?

Reply #8 – February 09, 2015, 11:40:14 am

I'm curious, if you installed the Helium fridge why did you use the backer board? It's my understanding that the Helium fridge eliminates the flammability concerns.

Re: Replacing Fridge with a residential and/or high efficiency electric?

Reply #9 – February 09, 2015, 12:45:48 pm

Thanks! :-)

A good list of issues to consider, so just to to provide context:

Full time for at least a few years.

Sometimes close to store sometimes not, we plan to travel a lot.

Pole to pole atm, but we are planning on working HARD to change that. The biggest barrier (and this bear on the Aquahot question below) is the fact that the Aquahot works great EXCEPT the diesel burner. It worked briefly, but we haven't been able to get into a decent place that can help diagnose. Haven't really had enough time in temperate conditions to get very far digging into it myself yet either. I've gotten some good tips here though and pointers to specialized Aquahot resources. We're hoping to get the diesel burner issue nailed down either before or during the service visit to FoT.

Don't mind running the generator, but would prefer to minimize it, hence...

Solar on roof is planned. I've got a potential layout that puts about 1600 watts up there with the strong possibility of removing the satellite dome to free up more space. We're also looking at removing the 3 moribund 8D AGM batteries and replacing them with 2 8D Smart Battery LiFePo lithium ion batteries that will give us 600 amp hrs of 100% usable discharge (they actually list them as 300 amp hr but they must be 375 or thereabouts as the 300 is 100% usable rather than the normal 50% for Lead or 80% for Lithium Ion.). Doing the math that gives us substantially more usable power than 4 Lifeline AGM 8D batteries (255 amp hrs) @ the recommended 50% discharge. The Smart Batteries are DANG expensive, but they auto protect themselves from over discharge or over charge conditions and are supposed to be good for 2000 - 5000 cycles with all the other benefits of Lithium vs Lead.

I hadn't really considered removing the propane completely, the Gagganau stove has been great, and both the cooks love it. We did pick up an induction hotplate which is also great, but given the amount of cooking we do, it might make sense to keep it so that cooking has little impact on the electrical budget. I really haven't looked at how much space we could get back by removing the propane altogether though. Adding more batteries isn't a space issue, we could double the planned house bank in the existing battery rack to 1200 usable amp hrs (which to me seems like it's getting into monster house bank size) and still be under the weight of the 3 AGM batteries we have, and there IS space for 4 8D in the battery rack. I'll have to ponder the potentials of removing the propane. Off the top of my head I think it's a change we'll want to do some testing before we decide, the energy usage of induction is pretty dang steep from what I know, so we probably need to keep a log of how much we use the burners and figure out some method to convert that to an estimate of the watt hrs needed for cooking on average.

The overriding concern (as you so wisely pointed out ;-) ) is how DW and DD feel about it. At the moment they are ambivalent. I think the convenience of having it switch to gas and keep running on the road is novel enough that they're happy. As you said though, if they look at a nice residential install that is likely to change. To be frank, that inclines me towards the residential more than anything else. We want this to be an experience that everyone enjoys, not something they tolerate. If a better fridge solution makes that much of a QOL change, it's probably something we should do.

I really wish it was easier to figure out how much of an electrical energy budget would need to be devoted to a residential fridge. ::sigh::

Another thing I need to do some deep research on before we make final decisions for the next few weeks efforts. On the positive side, it looks like maybe I can shelve the micro replacement and do that later. Small blessings... :-)

James

Re: Replacing Fridge with a residential and/or high efficiency electric?

Reply #10 – February 09, 2015, 01:37:40 pm

Agree that you should search the forum archives for fridge replacement articles. Lots of good ones.

Several years ago, I replaced our small 2 door Dometic (6 Cu Ft) with a Whirlpool that fit in the same space and is ~10 Cu Ft. Space improvement was dramatic, and the freezer really works now, plus you can pack fridge and freezer full and not worry much about convection cooling. Your OEM fridge will be much larger, but the improvement in storage would be a wonderful thing for a family on the road.

We have 500W of solar, and it keeps up with the fridge and the outboard icemaker and tops off the batteries, so with ~1100 W you should have no problem.
For power management, I put the fridge on its own inverter, so at night we can turn off the main inverter to eliminate parasitic loads. We do run our gen when we run the microwave, toaster/convection oven, or induction cooker, and feel that is kindness to the main inverter, plus reduces the need for two more 8D's

Re: Replacing Fridge with a residential and/or high efficiency electric?

Reply #11 – February 09, 2015, 02:03:28 pm

Kent,

Good point. While there is no longer the ammonia flammability hazard, there still is an open flame present. With the vibrations associated with coach movement, there is the possibility of a propane leak developing at some time close to the flame. Our coaches don't have the later foam to at least be partially fire resistive but have the balsa/laun wood surrounding the fridge. With the new fridge installation, you can see the floor is several inches lower than the OEM fridge and gives a space for the heavier than air propane to collect before it can vent out the exterior access door. My worry here is that a flash fire could ignite any rodent nest or dust bunnies and in turn, catch the wood on fire. The backerboard installation makes it easy to seal off the compartment from the living space so any propane leak would be confined to the fridge compartment.

There is also 12V as well as 120VAC in the compartment. The outlets are exposed to the atmosphere and difficult to inspect for corrosion and heat buildup from high resistance. The backerboard insures that any overheating condition would not have a combustible product close by. It also safeguards against any malfunction of additional fans mounted in the compartment.

Since the compartment floor has to be rebuilt anyway, the backerboard is an easy and inexpensive addition. It also gives the opportunity to organize the wiring as the stock installation was a mess.

Pierce

Re: Replacing Fridge with a residential and/or high efficiency electric?

Reply #12 – February 09, 2015, 02:04:30 pm

Quote from: Tigratrus – February 09, 2015, 12:45:48 pm

We're also looking at removing the 3 moribund 8D AGM batteries and replacing them with 2 8D Smart Battery LiFePo lithium ion batteries that will give us 600 amp hrs of 100% usable discharge

Curious if you've chosen your replacement inverter yet, and if so which did you go with?

Re: Replacing Fridge with a residential and/or high efficiency electric?

Reply #13 – February 09, 2015, 02:37:53 pm

Haven't made a decision at this point. The Freedom 25 is actually still working pretty well as far as I can tell. I've been thinking about a Victron so that we can use it to boost a 15 amp line in for when we are visiting with friends that don't have any other kind of electrical available. I'd really like better monitoring etc, but I know an individual that recently had a pretty decent solar setup installed on his '95 u320 and they left the Freedom inverter in the mix as there was no reason to change it out.

Is there something we should be aware of with the Freedom 25's?

James

Re: Replacing Fridge with a residential and/or high efficiency electric?

Reply #14 – February 09, 2015, 04:38:16 pm

Quote from: Tigratrus – February 09, 2015, 02:37:53 pm

Haven't made a decision at this point. The Freedom 25 is actually still working pretty well as far as I can tell.

Is there something we should be aware of with the Freedom 25's?

It's not compatible with LiFePO4 and their charging profile. You need an inverter/charger that works with that technology so you'll have to replace the inverter when you change to those batteries.

ETA start here Lithium Ion Batteries for RV Motorhome House System - LFP / LiFePO4 |... and in particular Living the Lithium Lifestyle – 3.5 Year Lithium RV Battery Update | Technomadia for some real-world RV LiFePO4 battery information.

Re: Replacing Fridge with a residential and/or high efficiency electric?

Reply #15 – February 09, 2015, 05:17:47 pm

Quote from: Tigratrus – February 09, 2015, 02:37:53 pm

Haven't made a decision at this point. The Freedom 25 is actually still working pretty well as far as I can tell. I've been thinking about a Victron so that we can use it to boost a 15 amp line in for when we are visiting with friends that don't have any other kind of electrical available. I'd really like better monitoring etc, but I know an individual that recently had a pretty decent solar setup installed on his '95 u320 and they left the Freedom inverter in the mix as there was no reason to change it out.

Is there something we should be aware of with the Freedom 25's?

James

The Freedom 25 is a modified sine wave inverter, and some appliances are much happier with a true sine wave. This will be especially true of recent energy efficient electronics, many of which use what's called active power factor correction (PFC) (...let your eyes glaze over...you are getting sleepy...) and are unhappy with modified sine wave supplies. Also will be less efficient, which might be a concern with solar power. For normal loads like lights and DC motors, and older appliances, modified sine wave power won't be a problem.
Running induction motors on modified sine wave supplies can make them run hotter. Ditto for recent microwave ovens, I hear.

A number of folks have upgraded to Magnum inverter-chargers (we have one and its been great), and Magnum also has "hybrid" units that augment the shore power from battery as required (sounds like that's what the Victron does?)

Re: Replacing Fridge with a residential and/or high efficiency electric?

Reply #16 – February 09, 2015, 07:01:02 pm

Quote from: Kent Speers – February 09, 2015, 11:40:14 am

I'm curious, if you installed the Helium fridge why did you use the backer board? It's my understanding that the Helium fridge eliminates the flammability concerns.

Kent,

It could be overkill but I wanted to have some extra protection after seeing the bare foam insulation and wood in the fridge compartment. There are electrical wires back there and I already had the exposed plug for the fridge to burn up. I believe the Hardie board is very resistant to flame and I used it with good results on the siding of my house after Hurricane Katrina. I also believe that covering the exposed blue styrofoam board will help in keeping the heat/cold from the vents out of the interior of the coach. This fridge also has an optional fan on the back for ventilation that runs when necessary. Later on I can add a fire suppression system for even more safety and piece of mind. Please excuse the upside down pics.

Jerry

Re: Replacing Fridge with a residential and/or high efficiency electric?

Reply #17 – February 10, 2015, 09:12:12 pm

Excellent info, many thanks. I wasn't aware that the Magnum line had products that did the same thing as the Victron to supplement the shore power. Sounds like our timing has been good.

Not sure that the LiFePO4 charging profile is needed with the Smart batteries as they have built in systems that can handle simplify things a bit, I think you basically just need to be able to set the charge to 14.6 both bulk and float? Obviously it's something I need to research in more depth and I appreciate the heads up. I would certainly be happy with a new inverter that provides better monitoring capabilities, so that would be a major plus and improved efficiency could make a sizable difference over time. So that's another thing that I need to research. Thanks for the links to useful topics Michelle! :-)

James

Re: Replacing Fridge with a residential and/or high efficiency electric?

Reply #18 – February 11, 2015, 08:29:00 am

James, if you read techno media carefully you will see that he actually has run his air conditioner off his batteries and solar setup. Float is one of the issues that has caused his batteries to decline he used a lower float voltage. Heat was also a factor. The new technology available today addresses these issues. Since you're going that route his three and a half year experience should provide you with good guidance.

Re: Replacing Fridge with a residential and/or high efficiency electric?

Reply #19 – February 14, 2015, 12:22:02 am

Well, it looks like Samsung RF197 has been replaced by the RF18HFENBSR? AJMadison and HomeDepot both claim it as the new version. We'll be meeting again with Dave and a couple others in the remodel group to talk specifics and see if they think it will still work. The measurements are very slightly different, but probably close enough.

The big question is how much power it uses. Check my formula?

The docs on this unit claim 594 kwh / year. Ok...
594*1000 = 594,000 watt hours used in a year.
594,000 watt hours / (365 * 24) = 594,000 watt hours / 8,760 hours (in a year) = 67.81 watts

So on average, this refrigerator uses 67.81 watts? That should be something we can manage pretty easily with a solid solar array and large lithium battery bank.

Appreciate all the helpful comments on this and other threads about the topic. Now we'll see how it goes when we talk to Dave about it on Monday.

Hope everyone has a great weekend and Valentines day! :-)

James

Re: Replacing Fridge with a residential and/or high efficiency electric?

Reply #20 – February 14, 2015, 08:56:37 am

The sticker inside the door on our Samsung RF197 says "Maximum Ampere = 3.9 Amp". The ice-maker (from what I have read) uses extra power to heat the tray when dumping the ice. We use our ice-maker when plugged in (it works GREAT) - when boon-docking we turn it off.

Re: Replacing Fridge with a residential and/or high efficiency electric?

Reply #21 – February 14, 2015, 09:50:16 am

We have an RF97 as well. And I recall the energy use sticker on ours was more like 460KW/year.

James, the math is right but figure the refrig only runs 1/2 time, the inverter is maybe 80% efficient so average load while running may be more like 170 watts Peaks are going to be higher, for the RF197 about 600 watts.

The replacement is about the same width 32-1/8". It is a bit taller. Carol and Jeff just had FOT put in the newer one. Make sure the doors clear sliding door tracks or any other obstructions. I did mine myself. Pretty straight forward. The RF197 has no on/off switch so if you want to turn it off you either need access to the plug or make the outlet a switched outlet. I moved the outlet to under a bottom drawer in the kitchen and put the switch and another duplex outlet on the forward end of the kitchen cabinet. If you have the 36" wide gas refrig then there is enough room for a 3-3/4" wide pantry next to the new refrig. We have found ours to be very useful space for trays and anythingthat will fit. Alum foil, cake mix, pancake mix, soda cans, sink cover, trays, lots of stuff.

Roger

Re: Replacing Fridge with a residential and/or high efficiency electric?

Reply #22 – February 14, 2015, 05:15:23 pm

The advantage of a marine type fridge is can be more efficient and you don't have to run your inverter. I've heard that the new marine
fridges don't cycle, the compressor slows down when it get down to temperature rather then shutting off and speeds up when needed
so you don't have the surge when starting up

Re: Replacing Fridge with a residential and/or high efficiency electric?

Reply #23 – February 14, 2015, 09:00:40 pm

My net cost after selling the LP fridge was $710. 4 or 5 times to get to a custom fit Sea Freeze. We are plugged in more than 90% of the time so it was a good fit for us. Your fit my be different.

Roger

Re: Replacing Fridge with a residential and/or high efficiency electric?

Reply #24 – February 15, 2015, 10:01:27 pm

Welp, in a somewhat unexpected change of plans we are now getting the 8.1 cubic foot Vitifrigo dp2600 from Defender. Turns out BOTH Susan and Elizabeth (our 12 year old chef in training) much prefer the sleek look of the flush mounted Vitifrigo, not to mention the integrated door latches and shelf rails to keep things from sliding off in transit.

From an engineering perspective I'm much happier with something that uses 8 less inches of height, almost 8 inches less width and uses substantially less power. It's also DESIGNED for rough service in a mobile environment, as well as running directly off the 12 system so you save the 6-10% inverter efficiency hit. We'll also be able to shut down the inverter to eliminate the phantom load without any effect on the fridge.

The most BIZARRE thing? The Vitifrigo, a purpose designed and engineered MARINE refrigeration system will actually be LESS expensive than the commercially available (Sears, Home Depot etc) Samsung residential fridge when all is done. When we spoke to Dave Friday about replacing the fridge he said that putting the marine fridge in would be 1/2 the installation cost of the Samsung. Running the numbers the total installed cost of the Samsung was going to be about $3500-$3800. The Vitifrigo is right about $3000 installed based on my quick and dirty math. I've never seen a comparable marine system of any kind be LESS expensive than the normal residential version. :p

The extra space along the side of the vitifrigo (the dp2600 is less than 24" wide compared the the Dometic RM 7832's 32") gives us just enough room to put in a full height pull out between the fridge and the stove exactly where spices, oils etc would be best stored for use in cooking.

And the increased electrical efficiency will be a major boon to my electrical budget for dry camping. The samsung was going to eat essentially the entire output of the 4 panels (420 watts) I was going to be able to add by removing the satellite dome.

So... How does one go about selling a still functioning Dometic Elite RM 7832? :p

James

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