Refrigeration A25

[Sunsetrider]

Long winter, sitting here thinking of adding refrigeration and I wonder what others have done. I am thinking along the lines of a 12/24/110 fridge/freezer from the likes of ARB, Engel, etc. I think the best location might be the area between the aft beds, but I want to see some in person to decide of I should get a 40 or 50 litre box. But Even then I have some questions, like:

- I would leave the existing pull-down icebox opposite the helm station in place as a cooler for drinks with an ice block, but other than that how do people decide whether to run the unit as a fridge or as a freezer? On a small vessel like this with no other refrigeration source?

- Generally these seem to run at 2.2 amps or so and the trucks seem happy to run them off the starting battery. Normally mine would run off the 115AH house battery, and as you might imagine this boat does not run significant draw even at anchor - the windlass only when the engine is running.

Should I simply run the wires to the fridge off the extra slot on the breaker panel and leave it at that, see how it goes?

Should I consider a separate battery for the fridge, and if so, how would it tie into the charging system (alternator and on-board dual-battery charger). I have an extra "marine" battery lying around - we know those are not true deep cycle but these fridges do have a battery-protection cut-off thing.

I would run 12 ga wire to and from the battery room under the helm rather than using the wire provided by the mfgr.

How do others power a fridge on these boats?

[Beta Don]

IMO something like an Engle would be hard to beat on a small boat - Dollar for dollar and amp for amp I don't see anything that comes close

I custom built a 12 volt fridge/freezer into a high quality 3 cu ft icebox (2 cu ft fridge and 1 cu ft freezer) and it worked well, but I had right at $1400 in it by the time it was all said and done. We made ice cubes every day (we drink lots of iced tea) and it kept everything cold using around 25 AH per day. I ran it off a pair of AGM golf cart batteries with a pair of 150 watt solar panels, so you could say my ice cubes and cold beer cost me right around $2K - You can buy many, many bags of ice over a several year period for that kind of $$$

An Engle would be very price competitive and there are few commercial units which use less electricity that I'm aware of. As a bonus, you could use it in the car/van when traveling too

Don

[dkirsop]

I have an Engle mounted on a tray that slides in and out on drawer slides. It is mounted in the recess that previously accommodated a fridge. I really like the Engle as it is very energy efficient and quiet. I have two house batteries consisting of 2-6volt golf cart batteries each. I accidentally forgot to reconnect one bank a summer ago and never noticed the difference so I think your one battery bank will be fine. I do have a solar charging panel on the boat which I find very useful. I would recommend the solar panel rather than a second battery bank.

[Sunsetrider]

dkirsop - I do have a single solar panel - a basic one - that I haven't hooked up yet. I plan on attaching it with velcro so I can move it around. Can I ask: what size Engle do you have? do you use it strictly as a fridge? Were there major issues installing the slider? Do you have any pics?

[Beta Don]

It's nice to have two separate banks of batteries and a battery switch so you can use them separately and start the engine using either bank. If you elect to go that route, the biggest bang for the buck in boat batteries is to use 6 volt golf cart batteries in pairs for 12 volts. If you can find room for 4 of them, you'll seldom lack for electrical power. If you can't, try to fit a single pair as your 'house' bank and use a smaller marine deep cycle battery as your engine start battery

Using the 'don't discharge them below 50% rule' a single 55 to 60 AH marine battery will give you around 30 amp hours of usable juice, while a pair of 200 AH golf cart batteries in series for 12 volts will give you about 100 usable amp hours, or more than triple what a typical marine deep cycle battery can do. As an added bonus you can expect about twice the life span from the golf cart batteries - 5 to 6 or 7 years is pretty typical if you have a good 'smart' charger and you check the water level regularly. In the long run the golf cart batteries will actually be cheaper to use too

Don

[Sunsetrider]

I've thought about switching my house (115 AH) deep cycle battery for a pair of golf cart batteries. So far i haven't had the need. I will likely do so before heading out on the Big Adventure.

[Beta Don]

The reason small case deep cycle marine batteries don't last as long as golf cart batteries is they are cramming the absolute maximum number of amp hours into the smallest case they can and that means the oversized plates come very near the top and bottom of the case - Not so with golf cart batteries. All batteries shed plate material as they age which falls to the bottom. If there isn't sufficient room left at the bottom between the plates and the bottom of the case, that material shorts out the plates and ends the service life of the battery. If you lose even a small amount of water and don't replace it, the tops of the plates are exposed to air and that lessens their life too

Golf cart batteries are built with extra room at both the top and the bottom, so a normal loss of water doesn't expose the tops of the plates. As you can imagine, they were specifically designed for use under very rugged conditions and for pretty extreme off level angles found in golf carts

With either battery type though, the key to long life is to make sure you use a quality 3 or 4 stage 'smart' charger which switches to a very precise float voltage at the correct state of charge. That needs to be adjusted for both the battery chemistry (flooded, sealed and AGM) and also the ambient temperature. Spending an extra $100 to $150 or so on a good charger vs a cheap one will pay you back many times over in extended battery life - Your batteries will gas much less and thereby use less water, so the likelihood of a low water condition ruining the battery is greatly reduced

One last bit of advice for anyone considering golf cart batteries is . . . . purchase water saver caps for them. These caps condense much of the water vapor which usually leaves the battery while under charge back into water which drips back into the battery. They can cut the water use of a golf cart battery by as much as half to 2/3rds and that helps extend life too . . . . or at least it allows you to check the water once every couple months as opposed to once every couple weeks

One source for them is http://www.flowsystemsusa.com but you can buy them elsewhere as well

Don

[Sunsetrider]

Don - have made note of your comments for when I move to the GC Batts. And would mention that I do have a "smart" 3-stage charger, designed for a dual battery set-up. I have it wired in to accommodate the "smart" charging from the ACR when underway.

[dkirsop]

I do not have a good picture of my installation and it will be awhile before I am in the boat again so that will have to wait. I have a smaller Engle due to head room clearance issues. This is because my second bank of house batteries is located under the shelf that supports the refrigerator. Without the batteries you can configure a shelf to accommodate one of the larger units (I would do this but it is not a big enough issue for me). We use the Engle as a fridge but it is a little on the small side. Water here is cool so the bilge doubles as a reasonable cooler. My recommendation is go with a single bank of house batteries, 2 x 6V golf cart batteries, and a larger cooler. All of the Engle units use the same compressor unit so there is no energy increase to speak of.

My solar panel is a flexible unit that sits across the helm roof and is tied in place when in use. As I noted before, we used it for an entire unit on only one house bank and had no issues.

[dkirsop]

I found some old pictures that show the solar panel and the fridge location. My solar panel is 32watts. I installed a solar charge regulator which reduced the need to top off the batteries significantly. The regulator cost was less than $100Can.

Solar Panel.jpg

Fridge.jpg

[Sunsetrider]

Thanks, that's helpful. I need to get some measurements on the boat before making final decisions.

[Sunsetrider]

Cursor froze, lost a lengthy post. Grrrr. Here goes again. Very much shortened version.

Cottage show today, found a company located just down the road from where I live, selling a range of off-grid products, including Unique brand fridge/freezers running AC DC Propane. Caught my eye was the 60l. version, ac/dc, with 2 compartments so you can one as a fridge and the other as a freezer. Perfect for what I want. 2.7A draw, pretty good. From downunda. All features seem excellent with one drawback: does not appear to have the feature that protects against battery drain.

Is there an accessory one can buy to address this?

[Sunsetrider]

Actually, never mind - I downloaded the manual and note that it does in fact have low-battery protection the voltage of which can be set manually. Very few reviews of this brand online, and not included in any comparos. But it seems to be a good product from its features and usability. I love the ability to set the temp of each compartment individually, including the ability to shut one side off to save power. They have 3 models: 120l., 80l., and 60l (2.1 cf). I need to get up on the boat somehow to take some measurements before deciding on the 80 l. or the 60 l. All things being equal I guess bigger is better on a long cruise, and it seems the power draw is the same for each one. Then to decide whether to stash it in the aft cabin or to refit the icebox area opposite the helm on the port side. If the latter, a slider will be needed, so how to attach that?

http://uniqueoffgrid.com/product/portab ... 80-litres/

[JT48348]

FYI: Since this topic came up I have been doing some research on these top loading refrigerators, becuase I'm going to put a frig unit in my newly crafted galley. I didn't know alot about top loading refrigeration/freezer units that ran off actual compressors as opposed to the cheaper ambient air set-up.

There's a variety of information and first hand users comments on a variety of forums related to overland travel, expedition travel, etc used by people in a variety of extreme locales and conditions around the world. Based of this, I've come to the conclusion that most of the boxes use the same components such as the compressors etc. These compressors and their performance are all very well documented in the real world, and as 12v systems and are very good. Often the same components are used in top loading and side loading units. The variations in the Amp hours usage between units is largely a matter of "creative advertising." Different companies claim different power usage rates, but they are estimates, often in best case scenerios. Some numbers are simply more accurate than others, becuase the companies are not over inflating. Meaning: there's actually very little usage difference bewteen units.

That I can tell, the ASU technology in the Isoltherm units is an outlier. The "smart" technology does in fact reduce the typical power usage becuase it cycles the unit on and off in a smarter way. In addition, where people are getting really amazing numbers and usage out of their top loading units is when they drop them into a cavity that has further insualtion to add to the insualtion in the box. It goes without saying that top loading units are unherently more efficient than side opening units.

Where there is a price difference in these untis is marine vs non-marine and the branding there-in. This is true for both top loading and side loading units. I'm intrigued by the idea of the more efficent top loading unit, that be more portable, but unsure how it relates to actual "live aboard" lifestyle. One of the things that facilitated my extended live aboard time was having a "normal" refrigerator, even a smaller mini-size one, that opened and accessed just like at home. I'm curious how convientient it is haveing to root aorund inside a chest for whatever you need. Maybe in the long run its a good trade off for more effiency.

[Beta Don]

Granted it's easier to find what you want in a front loader and if energy consumption isn't really an issue, you can go that way - Power boat with engine running most of the time, big enough batteries to last when it's not running, solar panels or genset to help out and you don't plan to be anchored out for several days at a time . . . . or not? For most small boats without big batteries, big solar panels or a genset it's probably not practical. A typical front loader can use twice the energy as an equal sized top loader if you're in and out of it very often

All other things being equal, the big downside is that every time you open the door, all the cold air falls out on the floor and your refrigeration system goes to work to cool all the warm air you replaced it with. If you could live with only opening the box a couple times per day, that might not be such a big deal, but you'll probably find yourself in there at least every hour or two - Your compressor could end up running most of the time on hot days

Top loaders are more like the freezer compartments you find at the grocery store - Even with no top at all, so long as the air isn't disturbed there isn't that much cold wasted - Heat rises and cold falls

Published amp draw numbers should be taken with a grain of salt as the actual energy used varies a LOT depending on many, many factors. It's a given that for an equal amount of insulation, the larger the box the more juice it will use. All compressor units will cycle on and off and the ratio of off to on will determine the actual 24 hour amp draw. That ratio is determined by insulation (heat gain) how often you're in the box, warm items added to the box and are you keeping (or making) ice or not. A good practice is to add your new items and fill your ice cube trays in the morning just before you head out, as your engine will be running for hours and it doesn't matter so much how much energy your icebox is using for the next several hours

An advertised 2.5 amp draw would consume 60 AH in a 24 hour period and it will likely be more as you'll be in and out of the fridge and adding warm items periodically

If you plan on having DC refrigeration I would say a dedicated pair of golf cart batteries to power it would be a minimum, and two pairs would be even better. A single pair rated at 200 AH using the 50% rule will only give you a usable 100 AH and you *could* go through nearly that much in 24 hours . . . . more if you count lights, pumps, TV, radios, recharging phones & tablets or any other power you'll be using. We had a pretty efficient 3 cu ft top loader (Isotherm compressor) with two pairs of GC's and two 160 watt solar panels and a 2.5 Kw diesel genset. Living for a week on a mooring ball in Boot Key Harbor at Marathon we still had to run the genset at least every other day to charge the batteries. With two pair of GC's, you can really make good use of a high power alternator or a genset

If you plan to spend most of your nights tied to a dock in a marina with AC power, you can surely get by with less . . . . but IMO a front loader on a small boat with small batteries, small solar panels will be problematic for anything more than a quick overnight at anchor

Don