Home refrigerator in catamaran?

[Jef & Marin, Netherlands]

We have 2 fridges in our catamaran. Both are w*d*h of 52*52*75 cm. One is an Vitrifrigo 115 from 2003. It is economical in power consumption but needs frequent defrosting. The other is an Isotherm CR130Drink from 2015 which never needs to be defrosted but which has almost double the power consumption of the Vitrifrigo. They are installed above each other.

I am considering to replace these 2 with one European double height model. Current idea is an in-built one-door fridge-only model which has an A++ or A+++ energy consumption rating. These don't run anymore on CFC's but on butane or pentane.
Objective would be to have more space and reduce power consumption. And to stop having to defrost the Vitrifrigo. Presently they take around 32Ah + 60Ah = 92Ah on 13V per 24h in tropical conditions.

To fit such a fridge I will need to make big and irreversible changes to the interior of our boat. I want to avoid to installing one and then finding out that it doesn't work in a catamaran.
I would appreciate your comment. Maybe from people who already tried?

Some of my questions and worries:
1. Power consumption: We will need to run a 230V invertor full time. I understand that domestic fridges need quite a big invertor for start-up. We have a Mastervolt Mass Sine 12/2000 from 2003 which only takes 5W with no load and which we could run 24/24. Or I might buy an extra invertor for the fridge. What size of invertor is big enough?
2. Are the power consumption figures by the manufacturers realistic? These are linked to the power consumption ratings like A, A+, A++ and A+++. Or is it like the car fuel consumption figures where the car companies do every thing they can think of to present nice but irrealistic figures?
3. Do the fridges work well despite the motion of catamarans? We do a lot of long passages.
4. Will the compressor wear out faster because of the motion? Maybe the bearings? The Danfoss BD35 seems to be designed for mobile application, maybe the bearings are stronger than domestic fridges?
5. Will the condensation water that runs down on top of the compressor (where it evaporates) run over the edge by the motions? Might we connect a hose and bottle in the bile to catch this water, to prevent this overflow?
6. Do I need to make a lock on the door? The door will be facing forward, not sideways.
7. Heat: The build-in models mostly have their condensor on the rear. Anyhow, there will be air space of around 10 cm all around, and air inlet from below and top
Of course I am also very interested in other issues that could be important.

Thanks for your feedback,
Jef

[a64pilot]

First I moved, or think I have moved this from the forum help section which is for asking questions about the forum software etc and put it in electrical.
First I don’t think it being a Cat is going to make much difference.
In my opinion if you can disable the heated doors and seals and disable the frost free, then you will greatly reduce power consumption, there will be some efficiency losses from the conversion of course.
I’m under the impression that a majority of power consumption is heating the component parts to reduce condensation and making it frost free.

I don’t think your other concerns will come to much, except keeping the doors closed and developing some fiddles on the interior shelves, similar to what is done in Caravans.

Before I jumped into it and cut my boat apart, I’d set it up in my house and run it to see what the consumption really is and if I could live with that number.
You could measure with a simple Watts up meter and just calculate the conversion losses. I’d have a dedicated pure sine wave inverter, and one that is no more than twice the needed amperage.

I think it’s going to boil down to if you have enough excess power now, likely you will have to increase your Solar or battery bank capacity or both.

[Jef & Marin, Netherlands]

Hi A64pilot,
Thanks for your answer, and for moving the thread.
The European fridge I am considering is a Liebherr 230 liter / 140 cm high having an official power consumption of 83 kWh per year. That is 1/4 of a kWh per day. The European fridges are now quite power efficient. There can not be much anti-icing heating in door rubbers with such power figures.
Loss of the inverter will probably add 10 %.
The combined power consumption of our 2 fridges is around 92Ah at 13V. This is around 1.2 kWh.
So if there is not too much cheating in the official power consumption, we could reduce the power consumption around 4-fold.
I am interested to know how much cheating there is in these official European power consumption. Remember the European Diesel car exhaust gas scandal.
We have adequate battery power and solar panels, and bigger will not be ncessary by the power reduction.
A friend told me that the start-up current of the compressor will take a high peak power.

Regarding monohull or cat: I feared that the heeling of a monohull would be mentioned as a problem. Therefore I mentioned that we have a catamaran.

Yes I guess I will have to add anti slip tape or edges to prevent stuff falling out. And maybe latch the door?
Thanks again,
Jef

[a64pilot]

Go take a look at Caravan fridges, they likely see just as much if not more motion than a Boat, to see how they handle the door and shelves.
I don’t have an idea how much of an angle a normal fridge compressor will tolerate, but would be surprised truly if they are any different than mobile ones.
I doubt, even though that I’m sure several will disagree that there are many if any real “Marine” compressors, market is just not big enough to support it, I’d bet the same compressors are used in many, many different applications.
We have a Moderator that has been using a small house fridge on her mono hull for years, but it’s a small one.
Anyway I think it’s back to actually measuring the actual power consumption, I think that is the only way you will get real numbers.
Many things are variable, that I doubt are in testing, even our best Marine fridge manufacturers here test with the box in stasis, cause you have to have a standard, and if they didn’t then they would look bad compared to others.
However opening a box many times a day and adding warm food and bringing cold food out will really increase consumption.
Get one of the fridges or find a friend that has one and plug it into one of these, it will tell you to the watt the power consumption and it’s cumulative too, so if you plug it in at 4 PM today and look at it at 4 PM tomorrow it will show you exactly how much power you used in one day.
http://www.green-energy-efficient-ho...ll-a-watt.html

There are all kinds of course, some with more bells and whistles and I’m sure some will interface with a computer if you pay enough. Of course there are 220 V models too.

[kristjan]

I have used domestic fridges on several different occasions boats with no issues. Especially if you have some solar then you’re ok. On a large monohull, I had a 9 cubic foot top and bottom fridge and battery was two 4D and two 140 watt solar, I used a xantrex 1000 watt inverter. On a charter catamaran, I had two chest freezers and two stand up fridges and one bar fridge - all domestic brands - but that boat always had a generator running. On a small tug, I used a 305 watt solar and had a half size fridge freezer and never on shore power. My only caveat, find one that is energy star certified.

[44'cruisingcat]

We have a domestic fridge and freezer on our catamaran. They work fine, 8 1/2 years full time cruising and no issues.

You can fit child proof catches to prevent unwanted opening.

Your inverter will be more than ample. We run both off a 1000W inverter.

You may lose some efficiency, but there are new inverter technology fridges that are very efficient.

[valhalla360]

I'm confused. Is this a compressor based fridge or an ammonia absorption fridge (RV style).

The reason I ask is you mention Butane.

[mikedefieslife]

Interested in this.

I had a look at a Liebherr UIKP 1550 under counter unit. Supposedly at whatever the measured temperature is (probably 5c internal in a 25c environment), the power consumption is listed as 0.168 kWh / 24h. Perhaps my maths is bad, but make that just 168w per 24h period, which is incredible.

I have met people on large cats with cheap domestic chest freezers and the like, but they tended to run them from a generator or shorepower. Obviously by their nature freezers need much more power.

[Cadence]

Originally Posted by valhalla360

I'm confused. Is this a compressor based fridge or an ammonia absorption fridge (RV style).

The reason I ask is you mention Butane.

You posed a good question. Many RV reefers are absorption units using ammonia. You can run them on 120, 12 or propane. For Propane they need to be relatively level. No compressor to go bad.

The down side is recovery is not as quick. So buy a small dorm. reefer to hold the beer.

[valhalla360]

Originally Posted by Cadence

You posed a good question. Many RV reefers are absorption units using ammonia. You can run them on 120, 12 or propane. For Propane they need to be relatively level. No compressor to go bad.

The down side is recovery is not as quick. So buy a small dorm. reefer to hold the beer.

I asked because we had one on our catamaran. They don't work on a mono because they have to be level.

Other than the slow recovery, it was really a nice option. On shore power, it was quiet and reliable. Away from shore power a propane tank was good for about 3 weeks with no electrical consumption.

Only tricky part would be retrofitting on an existing boat.

[SV Bacchus]

Originally Posted by Cadence

So buy a small dorm. reefer to hold the beer.

Or an Engel, not as cheap but they are efficient and run for many years.

[Gordo1]

Hi Mike. I have been running one 14 cu.ft Electrolux deep freeze and two Candy (Hoover)
50/50 52ins tall fridge freezers on my trawler yacht for seven years in Croatia. In that time the only repairs to the fridges were two top ups of gas (Pentane has very small molecular link structure and can very easily leak compared to freon or R134a.about $100 each time as the the gas is very expensive but only a 15 minute job.When I bought them I worked out that they were worth it if they only lasted three years compared to a dedicated marine unit. They have give me no trouble other than losing gas and are many times more efficient than a marine one. by the way european Power ratings A AA AA+++etc relate to the overall annual running cost which includes the amount of insulation plus the efficiency of the compressor Other than at startup (which your mastervolt same as mine will easily handle. that unit takes 4kw for six seconds ) easily enough to start the fridges. Consumption is very low on running. If you send me some dimensions I will get some european unit power consumption figures for you.They have served me well over the years. You need to keep them filled up though as they actually use less power full than empty. I was going to use a dedicated inverter for my big fridge freezer but calculated that the master volt unit would handle it for two or three days your battery bank will probably be the limiting factor but if you are on a long trip you would be using the engines anyway. You do not say if you have a generator on board I have 1000Ah deep cycle battery bank which will run the three fridges for three days.send me you available space and i will send you some european fridge specs. I think Sears would probably have about 12 /14 cuft fridge freezers which would suit your need before you look at buying a European one. All EU fridges have an annual cost label on them and all you need to do is divide by 365 to see your daily power consumption which will amaze you.
Gordon Young Liverpool England

[davenrino]

Cadence Re: Home refrigerator in catamaran?
Quote:
Originally Posted by valhalla360
I'm confused. Is this a compressor based fridge or an ammonia absorption fridge (RV style).

The reason I ask is you mention Butane.

You posed a good question. Many RV reefers are absorption units using ammonia. You can run them on 120, 12 or propane. For Propane they need to be relatively level. No compressor to go bad.

The down side is recovery is not as quick. So buy a small dorm. reefer to hold the beer.

Originally Posted by valhalla360

I asked because we had one on our catamaran. They don't work on a mono because they have to be level.

Other than the slow recovery, it was really a nice option. On shore power, it was quiet and reliable. Away from shore power a propane tank was good for about 3 weeks with no electrical consumption.

Only tricky part would be retrofitting on an existing boat.

I have a Mono kept in a marina with shore power. Would these fridges have to be kept level if using 12v for day sails?

[Cadence]

Originally Posted by davenrino

Cadence Re: Home refrigerator in catamaran?
Quote:
Originally Posted by valhalla360
I'm confused. Is this a compressor based fridge or an ammonia absorption fridge (RV style).

The reason I ask is you mention Butane.

You posed a good question. Many RV reefers are absorption units using ammonia. You can run them on 120, 12 or propane. For Propane they need to be relatively level. No compressor to go bad.

The down side is recovery is not as quick. So buy a small dorm. reefer to hold the beer.



I have a Mono kept in a marina with shore power. Would these fridges have to be kept level if using 12v for day sails?

Shot answer yes. It is more critical on propane because of the chimney however the collected ammonia needs to be somewhat level in the length of the unit. II wish I could be more concise. There is a cylindrical tank at the bottom which needs to be kept relatively level end to end.

[myocean]

Hi Jef!
YES - get such a fridge, its great! They are not only a lot more efficient than small quantity marine fridges but even cheaper and more comfortable because they come with nice comfort features like perfect light inside.
We have done the same, yes Liebherr, too, cruised 3 years with no issues. See this thread: http://www.cruisersforum.com/forums/...att-90216.html, see especially my post on the last page.
I have used a dedicated inverter for this, just 23 or 250 Watt. Someone told me it needed to be one with a very good sinusoidal wave. So I chose a Victron Phoenix and simply tested it at home before shipping the fridge to the boat (catamaran). The compressor motors are said to have a relatively high peak power when starting. This is why the inverter should be quite a bit larger than the specified max power or amperage on the label of the fridge. I think something like factor 3 or 4 should be sufficient.

1. see above

2. Are the power consumption figures by the manufacturers realistic?
Yes

3. Do the fridges work well despite the motion of catamarans?
Never had problems.


4. Will the compressor wear out faster because of the motion?
Don't think so but we used it only 3 years. (Caribbean, Panama, NZ)

5. Will the condensation water that runs down on top of the compressor (where it evaporates) run over the edge by the motions?
I never cared about this issue and there was never any problem with condensation water.

6. Do I need to make a lock on the door?
From time to time this might be useful. In our case it was only on 2 or 3 tough passeges and we solved this temporarily with a tape during those passages

7. Heat: The build-in models mostly have their condensor on the rear.
Good ventilation is probably important for the energy efficiency. We had enough space on the back side and good passive ventilation.


Ulf