12V/110V/Propane Refrigerator

On another thread, (http://www.trawlerforum.com/index.spark?aBID=115492&p=3&topicID=44155608), FF mentioned how much he liked his propane refrigerator for quiet extended time at anchor.* Three weeks on a 20 Lb bottle with no worries about electrical power or extended genset running to support cold or frozen food. I'd love not to have to load $30 of dry ice in my cooler for a week on the water.

I've been wondering about these on a boat and would like to hear from FF and others on your opinion and experiences.

1. Are there marine combo units that take advantage of the 12V/110V/propane sources like RV models that automatically switch off propane when the other sources are available?*

2. Are the ones in use on boats today actually RV models?*

3. Does a boat installation require an external vent/hot spot side plate like RVs have?*

4. Are there special safety considerations in addition to propane sniffer monitors that should be considered?*

Incidentally, I already have 2 propane bottles mounted in a vented cabinet on the FB with a remote shut-off solenoid for the stove/oven.*

I appreciate your insight and advice.*



-- Edited by FlyWright on Monday 1st of August 2011 02:07:08 PM


-- Edited by FlyWright on Monday 1st of August 2011 02:10:19 PM

1. Are there marine combo units that take advantage of the 12V/110V/propane sources like RV models that automatically switch off propane when the other sources are available?

Usually not worth the effort of an automatic switch over , but 120V at dock side works fine should it be at your dock.

2. Are the ones in use on boats today actually RV models?

Yes, but for the more dedicated cruiser the Servelle model (just propane) has better insulation , made for the Amish, but no 120V electric.

3. Does a boat installation require an external vent/hot spot side plate like RVs have?

Yes the venting is CRITICAL and the mfg external vent is best.
A side vent or access is not usually required as most can be started from the front.

4. Are there special safety considerations in addition to propane sniffer monitors that should be considered?

The unit MUST be in an area where it can gravity drain overboard.

On our boat it simply lives in the aft cockpit which drains.

In an existing boat it would need a well about 6 inches deep that drains directly overboard.

Pour a big pail of water in the mounting location , if it all goes OB , you are fine , but do remember opening ports that might be lower than the drain.

Check with your insurance company (s) and see what they say.

Do the propane refrigerators work on different blends of propane?* The propane that we buy in Panama and Central America has a*higher butane component.*

FF wrote "The unit MUST be in an area where it can gravity drain overboard."

FF, Thanks for your reply. Is this for propane to vent overboard in the event of a propane leak? I could fashion an enclosed tub and a drain through the ER to an thru-hull vent.

Also, I read how it's critical that the unit be level for proper operation. Have you encountered any issues with this on your boat?

David, I never considered how inefficient the 12V option would be. Makes sense...thanks.

The external hot vent concerns me since I have side decks and would brush close to it every time I used the stbd deck. Depending on how far the vent can be positioned from the fridge, maybe I could vent it out the stbd aft wall of the pilothouse under the ladder and outboard of the door when slid open. Not even sure I'd have enough room there, but if there is, the ladder would provide protection from coming in contact with the hot vent.

The vent assembly must be directly above the unit , usually one wall of the rv serves as part of the duct system .

The vent is critical to the operation of the units and with a 12v muffin fan they would work, but would defeat the purpose of the system, no electric.

The tray and OB drain is in case the loss of the flame does not shut off the fuel.

It is a theoretical problem , that I have never seen , but Stuff Happens.

These units LOVE motion , a motor boat (or multi hull) is an ideal location.

The old units ( 1980 and before) did not like a heavy angle of heel, I have seen them (and kerosene fridges) in gimbals .

Newer RV units work fine IF you can stay in bed at that angle of heel.

FF wrote:
1. Are there marine combo units that take advantage of the 12V/110V/propane sources like RV models that automatically switch off propane when the other sources are available?

Usually not worth the effort of an automatic switch over , but 120V at dock side works fine should it be at your dock.

2. Are the ones in use on boats today actually RV models?

Yes, but for the more dedicated cruiser the Servelle model (just propane) has better insulation , made for the Amish, but no 120V electric.

3. Does a boat installation require an external vent/hot spot side plate like RVs have?

Yes the venting is CRITICAL and the mfg external vent is best.
A side vent or access is not usually required as most can be started from the front.

4. Are there special safety considerations in addition to propane sniffer monitors that should be considered?

The unit MUST be in an area where it can gravity drain overboard.

On our boat it simply lives in the aft cockpit which drains.

In an existing boat it would need a well about 6 inches deep that drains directly overboard.

Pour a big pail of water in the mounting location , if it all goes OB , you are fine , but do remember opening ports that might be lower than the drain.

Click to expand...

*

One thing I've learned about Health and Safety over the years is that whatever THE OTHER GUY is doing is horribly dangerous and should be illegal, and whatever I'M doing is the gold standard. I have an intense dislike for propane aboard but I recognize that this is irrational and it can be done safely with a bit of planning and attention to detail.*

If you're going to do it, pay attention to what FF posted. Also as DavidM noted, the sensors on propane (and carbon monoxide) detectors deteriorate over time and need to be replaced. Yes, you need one, but plan on having to replace it in a few years as part of regular maintenance.

We had a new 12/120v RV fridge installed four years ago. Every annual refit since the shipyard has had to futz with it trying to get the 12v side to work properly. It works fine during the day on 120v but craps out at night on 12v. First year it would freeze the fridge section, the next year it thawed the freezer section.

Two years ago the yard tech talked to the manufacturer and was told that the 12v section is not designed for extended use but rather for travelling between campsites where it is assumed the RV will be plugged in to 120v. I'm not sure how that differs from our daily pattern of anchor/sleep/travel/work but maybe the extra 1.5v from the charging system makes the fridge perform better. Or maybe the manufacturer is full of it.

Last year the yard installed a dedicated inverter for the fridge. Lasted about an hour out of the yard when the inverter started throwing a low voltage alarm. I thought maybe the yard hadn't installed large enough feed cables and since I was pressed for time we kept heading north and ran the fridge at night on 120v through an extension cord to an equipment inverter in the hold. During this year's refit they found the inverter itself was faulty, as well as its replacement. Three inverters later and maybe we have a solution. I guess those stories of recent Xantrex quality problems might have a grain of truth to them.*

*

My 110/12V Nova Kool cold plate with Danfoss compressor works flawlessly. For me, the lowest battery drain down is to run on 12V overnight and shut off the inverter. With 110V off the incipient drains from stereos, TVs, microwave clock etc are eliminated. Household fridges are power monsters on a boat - you gotta love those Sub Zeros for keeping the genset guys in business.

Propane fridges are good for anchors and underwriters. Have you noted the disclaimers on the safety valves? With a convection microwave and induction cooktop, we can cook Thanksgiving dinner onboard.* A propane oven is history for us.

The only experience we've had with propane refrigeration was on the first narrowboat we hired in the UK for our first canal trip. The boat was very old--- newer narrowboats all have 12vdc refrigerators even though the stove/oven and hot water systems continue to be propane (called Calor gas over there). But that propane refrigerator was the best we have ever experienced on any boat. It would keep milk at one degree above freezing with no draw whatsoever on the batteries. Narrowboats typically carry plenty of propane but they tend to be under-batteried and if you don't run the boat for at least a few hours each day there is a risk of running the "house" battery down.

We leave the refrigerator on our boat on 24/7/365 so the idea of a constant pilot light would preclude us from installing a propane refrigerator on any boat of our own. But I will say that based on our experience a propane refrigerator is terrific. A tri-powered refrigerator might be okay, I guess, but in the 13 years we've had our GB the 12vdc/120ac refrigeration we have on the boat has served us very well so far.

As to the stove-oven the only thing we will ever have on any boat we might own is propane.* Electric ranges and ovens are very inefficient and hard to control and require running a generator every time you want to fry bacon unless the boat is very heavily batteried.*

The only valid reason (as far as I'm concerned) that I've ever heard for having an electric galley on a boat was voiced by the chef of a 120' corporate yacht I was associated with for a while.* While he, like most three-star chefs, detests cooking with electricity he told me the problem with gas on a yacht used the way his is used is that you have to store it somewhere and there is the issue of what to do when you run out of it.* So he very reluctantly "put up" with an electric galley, although all the appliances he had installed are commercial restaurant grade which means they get way hotter and react much faster than non-commercial electric appliances.

My wife, while not in the same league as Chef John on the yacht, also much prefers cooking with gas so the propane stove and oven on our boat suit her just fine.* She's done full Thanksgiving (turkey) and Christmas (prime rib) dinners for six people on our boat in an anchorage out in the islands with no problems at all.* Had the galley been electric we'd have been running the generator all bloody day.* Fortunately, we carry a lot of propane


-- Edited by Marin on Saturday 30th of July 2011 11:51:43 PM

Two years ago the yard tech talked to the manufacturer and was told that the 12v section is not designed for extended use but rather for travelling between campsites where it is assumed the RV will be plugged in to 120v

This is correct the DC is very wastefull of energy and only used between camp sites.

It was a sop to the "safety" folks that worried that campers with their fridges on would be refilling in gas stations , with out securing the fridge.

Many of todays 2 way units units use a small (real trash) computer that will not allow the fridge to be used on propane for 20 min after the ignition is turned off.

The previous owner of my boat had a 12v/120v refrigerator that he removed because, in his opinion, it did not perform well enough at anchor. He installed a Sears 120v frig in its place and ran it off the inverter. It's still in the boat , runs great and doesn't put much of a strain on the 3000W inverter for a weekend. I may keep it!

110V only Rich Beers cold plate system.

Keith wrote:
110V only Rich Beers cold plate system.

Click to expand...

*Their website comes up in chinese characters. Are they out of business?

I think so.

There is no voting category for my refrigeration:* 12VDC only

When purchased 14 years ago, boat came with a dual AC/DC Norcold which worked good for 25 years, but was power hungry.**To replace it required a custom box, as nobody made this size box anymore (39.5" high).

By placing a 12VDC Danfoss compressor in the bilge (instead of being integrated in the box), we were able to double the freezer space and increase the reefer space by 1/3.* Power consumption is about 4 amps, and it runs about half the time the Norcold did (because of better box insulation, and*a more efficient compressor running in a cool space not requiring an inverter).* This was the best solution for our reefer/freezer capacity and power*needs.

Yes, custom was more expensive (around $1600 in 2002), BUT:* It is a simpler system, was able to reduce the*size of the house bank, and it significantly reduced our need to recharge the batteries (which resulted in reduced generator time and diesel fuel consumption).* Good value.

Same here, replace our old Norcold when it died with a Novacool 12 volt only. It has been great for the last 8 years running 24/7/365.

Same here 12 volt only. Cut our amp consumption from 120 plus per day to about 70. Replaced a Nevercold with an Isotherm with a remote Danfoss compressor.

Rob
37' Sedan

I voted but I use a combination.
Wheelhouse Frige and freezer are 240 V from mains and Inverter.
Combo frig / freezers on back deck are 24 V / 240 V units.

Just gotta be versatile.
Not a chance of the beer getting warm.

runs great and doesn't put much of a strain on the 3000W inverter for a weekend.

The strain is not on the inverter , the strain is purchasing new house batts if they are discharged below 50% and not recharged.

Not uncommon for good deep cycles that should go 6-7 years to be scrap in 2.

I wish I could remember where on the internet I saw an article that described the experiences one couple had on their sailboat with a propane refrig. They went to bed on the hook one evening with the husband waking up an hour later with a splitting headache. He went outside and he immediately felt better. He recognized what might be happening and tried to wake his wife. Could not wake her so he dragged her above. She survived but spent some time in the hospital. They found a pin hole leak in the propane supply line to the refrig.

I also considered propane until reading that article. Maybe the same reason I got a diesel powered boat so I don't have to deal with sleeping with a gas genny.

We returned from 12 days down in the Keys in May with a 120v/12v refrig and with the exception of 3 days in a marina, we were on the hook the rest of the time. We did not run the genny while on the hook. I did not notice any difference in the refrig performance while on the hook. I'll put a thermometer in the refrig and check, but that is my experience.



-- Edited by timjet on Thursday 4th of August 2011 10:36:25 AM


-- Edited by timjet on Thursday 4th of August 2011 10:37:24 AM

Interesting that the propane leak caused CO-like symptoms. My propane powers the stove/oven, but it gets used seldom. When it's not in use, the propane is turned off at the shutoff solenoid. If I had a propane fridge, I couldn't do that.

My 12V/110V also runs the same on either power source. I think the comments above about poor 12V performance were regarding the propane/12V models that require the 12V to provide heat for the system when the propane is not available.

I was told that mine is really a 110V fridge with a small built-in inverter that allows the use of 12V. So either way, the fridge runs on 110V.

"FWIW the 12V option is almost worthless. It uses about 10 amps, runs continuously and just barely cools. Not surprising as you are using 12V power to heat the refrigerant."

*

Sorry Dave,

No longer true I am also pleased to be able to confirm, as some others have also mentioned.* When my eutectic system failed, a system which is great until it developes leaks, then very expensive to repair, I kept the well-insulated frig and converted it to 12v only via a Waeco Coldpack conversion set.* It runs on about 1 amp draw, holds her at 4 degrees C no trouble, and with just the addition of an Airbreeze wind turbine to the couple of solar panels I had already added, we can run it 24/7 on the pick with the batts staying essentially fully charged...if there's a wind...minimally discharged and easily brought back up next morning if a still night, with some sun or a bit of travelling & alternator charge.

Here is a similar dsign with specs...

http://www.biasboating.com.au/p-2369-nova-kool-12l-15l-compressors.aspx


-- Edited by Peter B on Friday 5th of August 2011 04:50:50 AM

Folks wanting to change or test a box for electric use , can use this simple method.

Put a big block of ice in the fridge , close it and next day take out the block and weigh it.

Put it back in and wait a day ., or better 2 days.

Weigh the block of ice.

Under 5lbs per day and electric could be OK , depending on the system.

Over 5 lbs a day , find a better box.

FF wrote:
Folks wanting to change or test a box for electric use , can use this simple method.

Put a big block of ice in the fridge , close it and next day take out the block and weigh it.

Put it back in and wait a day ., or better 2 days.

Weigh the block of ice.

Under 5lbs per day and electric could be OK , depending on the system.

Over 5 lbs a day , find a better box.

Click to expand...

*I'll try it at Lowes, who wants to go to West Marine and be thrown out?

I'll try it at Lowes, who wants to go to West Marine and be thrown out?biggrin


Sears is the place to try this since they sell refrigerators AND scales. I'd suggest running up and down the escalators between departments, though, to get a more accurate measurement of the ice melt. (or grab a bowl from housewares to catch the additional melt!)