Fridge and watermaker on 27' mono?

[newhaul]

Originally Posted by drcat

three items or suggestions
1) consider adding 2 more solar panels of same size each on side rail near stern. They swing up using a support and can be set up at anchor and sometimes at sea. Several cruisers use - see youtube sailing sophisticated lady for an example
3) Consider a non compressor refrig called KECO It draws 35 watts when running can go as low as 81 deg F below water temp. It is not a thermo elect but draws seawater into a cpu costs around 400 euros, but you need to build the box See youtube sailing Uma for example 2 yrs ago
3) Watermaker - Seawater Pro $2800 12v, 8-12 gal/hr. see Adventures adrift youtube from about 2 yrs ago.
Good luck with your adventures.

the big problem with that Keco system is it is a Peltier plate system and drawn 5 amps average so 120 ah.

The solar instal setup is similar to mine and works great .

As to the watermaker setup well you get what you pay for.

[Q Xopa]

Originally Posted by drcat

three items or suggestions
1) consider adding 2 more solar panels of same size each on side rail near stern. They swing up using a support and can be set up at anchor and sometimes at sea. Several cruisers use - see youtube sailing sophisticated lady for an example
3) Consider a non compressor refrig called KECO It draws 35 watts when running can go as low as 81 deg F below water temp. It is not a thermo elect but draws seawater into a cpu costs around 400 euros, but you need to build the box See youtube sailing Uma for example 2 yrs ago
3) Watermaker - Seawater Pro $2800 12v, 8-12 gal/hr. see Adventures adrift youtube from about 2 yrs ago.
Good luck with your adventures.

All good advice.

Minor correction, I think the 12v water maker you are suggesting is a Sun Pure Water Maker. I hear they are both good.

[wingssail]

Originally Posted by Gene Neill

I'm on the fence between a Powersurvivor 40E and a Ventura 150. I'll leave it that. ; )

First off I think your power usage estimates are optimistic I'd guess that a refer, in the warm water areas, even a small stand alone unit, will probably eat 50-75 amp hours a day, or more. This is not including a water maker. Your 300 watts of solar will not produce 300 watts. You can probably plan on 10-15 amps for six hours, or around 100amp hour a day. So your solar might make it, if the refer is efficient and the sun is bright, and the panels are not shaded by mast or other obstacles. I'd guess you'll need to produce 100-125 amp hours a day, again, not including power for a water maker.

Your 40 amp alternator will not give you 40 amps unless it is driven relentlessly by a jacked up regulator, then the life will be short. You can run a much bigger alternator on a single belt (I have driven 130amps for years and years on a single belt system). You need a good external regulator and a alternator temp sensor, and either spares or quick access to replacement parts.

Two trojan T105's will produce about 100amp/hours before hitting 50%, so you will be maxing these on a daily basis without even considering a water maker. Additionally, that 50% figure assumes close to full recharging each day, not easy to do on solar, but possible with a few hours of engine operation and a good charging system, but again, that is not an optimal situation.

The water makers you mention (I have a small Power Survivor) will last longer if you run them with full voltage available. The motors draw more current and can get hot with low voltage. You will be surprised at how much fresh water you need. While cruising my wife and I use about 5 US Gal/day, which is 3 hours on a PUR 35 water maker, at 3-5 amps and included wash-ups with salt water and a fresh water shower every three days!

All of this adds up to a bigger power requirement than you estimated. I don't really like the portable gen-set option due to the size, weight, noise and separate fuel requirement but that would solve your power needs.

Our solution, which has worked for over 20 years of cruising and living aboard, has been 4 T105's, 250 watts of solar panels, and running the engine daily with a big alternator and good regulator and temperature protection. In cold water we can often get by on solar alone due to less frequent refer cycling but in the equatorial tropics we have to run the engine (we do have to replace most of this equipment periodically).

Don't let a limited budget, if that's one of your considerations, persuade you to estimate low. Living aboard with a refer and watermaker will cost you, no other way around it. Best to overbuild a bit in the beginning.

[drcat]

Originally Posted by newhaul

the big problem with that Keco system is it is a Peltier plate system and drawn 5 amps average so 120 ah.

The solar instal setup is similar to mine and works great .

As to the watermaker setup well you get what you pay for.

Regarding the KECO is there something I'm missing when I read these specs?

KECO - ATEN S.r.l.

The normal operating mode seems to be 2.6 amps and 1.7 amps on standby. The Burst mode amps is high but would seem to be limited time bringing temp down. Also no refrig runs constantly 24hrs a day, they cycle on and off and usually on much less than 50% of the time. I liked the KECO because it does not have a compressor, relies on water and does not heat up the cabin.

As far as the watermaker- yep it was Sun Pure for the 12v per another commenter. I had 2 watermakers in a listing and read the wrong co for the 12v version. Adventures Adrift seems to be happy with it, the 12v version, after 2 years although they did have a minor annoying leak at first.

[newhaul]

Originally Posted by drcat

Regarding the KECO is there something I'm missing when I read these specs?

KECO - ATEN S.r.l.

The normal operating mode seems to be 2.6 amps and 1.7 amps on standby. The Burst mode amps is high but would seem to be limited time bringing temp down. Also no refrig runs constantly 24hrs a day, they cycle on and off and usually on much less than 50% of the time. I liked the KECO because it does not have a compressor, relies on water and does not heat up the cabin.

As far as the watermaker- yep it was Sun Pure for the 12v per another commenter. I had 2 watermakers in a listing and read the wrong co for the 12v version. Adventures Adrift seems to be happy with it, the 12v version, after 2 years although they did have a minor annoying leak at first.

the keko unit is Peltier plate tech and not energy efficient in any respect.
The Peltier plate itself will use in the neighborhood of 5 amps and will have at least a 60% on cycle time .

[mitiempo]

Originally Posted by newhaul

the keko unit is Peltier plate tech and not energy efficient in any respect.
The Peltier plate itself will use in the neighborhood of 5 amps and will have at least a 60% on cycle time .

Yes, there is a good reason the off-roaders in Africa and Australia use Engel portables. They are the most efficient I have seen and reasonably priced. Nothing beats a compressor and the swing arm compressor in the Engel is the most efficient one available.

If you want a 12 volt watermaker the standard to look at is amps per gallon. Spectra leads the way and has worldwide service as well.

[Davo1404]

Have you thought about a portable water maker? Rainman do a petrol model in its own carry case, very similar in size to a 2kva genset
https://www.rainmandesal.com/

[Buzzman]

20 years ago I worked for one of an Australian 4WD magazine, and ran a heat-box test on all the 12V fridges then available on the market.
The Engel brand is somewhat ubiquitous on Oz, largely due to aggressive marketing, but since that time many other (mainly Chinese-made) brands have come onto the market at much lower cost.
Waeco is another well-known brand that is equally worth considering.
Engel use the Sawafuji 'swing motor', Waeco use the (near ubiquitous) Danfoss BD35 or BD55 in the larger models.
Most other fridge-makers uses these same compressors. Danfoss was highly regarded. In recent years taken over by Aurelius and rebranded Secop. All are made in China and have been for years.

Nitty gritty? In standard manufacturer-supplied box/container with minimal 20mm foam insulation, 32-36Ah is common in Oz but can be higher in tropical areas and if turned up to make ice.

Key to reducing Ah consumption is to utilise MUCH better insulation. Like 100mm (4in) rather then 20mm (3/4in). Cannot comment on 'new' (but definitely reduced) Amp draw as haven't done it or tested it, but stands to reason the laws of thermodynamics are immutable. You WILL use less power if you insulate more.

In our tests, even just adding the manufacturer-supplied 'insulated protective cover' (canvas-type fabric with an additional 4mm insulation) reduced Amp draw by a few Ah per day.

Also, Waeco and a few other makers offer DIY units which are ideal for custom-shape cabinets you often have to build into a boat, usually tapering down the side of the hulkl to a narrower bottom.

Another excellent tip for 12V fridges is to build the freezer compartment as a separate space, with 'spill-over' into the larger fridge compartment. Such a divider needs also a couple of plugged holes lower down in the divider to help regulate temps in fridge. Pull plugs when coolling down, re-install once 'balance' acheived. Vary as required.

Several of the combo portable fridge/freezer units (like Waeco) utilise this idea, but really don't have enough insulation to make it work adequately.

One thing that is certain is that 12V refrigeration is NOT set and forget.

You have to 'drive' the fridge, monitoring ambient and load temps, and adjusting motor cycling accordingly.

For example, when you get back from the supermarket and load the fridge and freezer, turn it up on full power and monitor the temp gauge till it reaches 4C in the fridge and -10C in the freezer before turning it down, then monitor for a day or so to find an acceptable 'balance' - otherwise you end up freezing milk and tomatoes, or not freezing (and thus rotting) meat.
And liquid ice-cream is no fun....

Many 4WD owners have found this out the hard way, after leaving their low-cycling fridge in a locked car for a few hours in the hot sun, returning to find that the car's inside temp has gone from 25C ambient to 90C ambient, and everything in the fridge has defrosted.

Ask me how I know....

[Gene Neill]

Originally Posted by Davo1404

Have you thought about a portable water maker? Rainman do a petrol model in its own carry case, very similar in size to a 2kva genset
https://www.rainmandesal.com/

Not really. I knew they existed, but to be honest I dismissed them somewhat out of hand. My thinking was, if I'm taking a gasoline engine on board, it might as well be a generator. But I'm always willing to listen if someone wants to change my mind!

[Gene Neill]

Originally Posted by Buzzman

Nitty gritty? In standard manufacturer-supplied box/container with minimal 20mm foam insulation, 32-36Ah is common in Oz but can be higher in tropical areas and if turned up to make ice.

Key to reducing Ah consumption is to utilise MUCH better insulation. Like 100mm (4in) rather then 20mm (3/4in). Cannot comment on 'new' (but definitely reduced) Amp draw as haven't done it or tested it, but stands to reason the laws of thermodynamics are immutable. You WILL use less power if you insulate more.

In our tests, even just adding the manufacturer-supplied 'insulated protective cover' (canvas-type fabric with an additional 4mm insulation) reduced Amp draw by a few Ah per day.

Great info, Buzzman. I have looked at Engel's insulated "transit bags" and wondered how much they might help. Much of the advertising has to do with blocking the rays of direct sun, which our fridge would never see. Beyond that, I had a vague idea of building some sort of styrofoam-lined compartment for it, with an open end for the compressor to vent. I was thinking 2"/50mm foam, but would certainly go thicker if space allowed.


Even our Yeti cooler full of block ice "sweats" a puddle of water when tucked when tucked away out of the breeze for a couple days, and that tells me something.

[Copacabana]

Originally Posted by Gene Neill

Great info, Buzzman. I have looked at Engel's insulated "transit bags" and wondered how much they might help. Much of the advertising has to do with blocking the rays of direct sun, which our fridge would never see. Beyond that, I had a vague idea of building some sort of styrofoam-lined compartment for it, with an open end for the compressor to vent. I was thinking 2"/50mm foam, but would certainly go thicker if space allowed.


Even our Yeti cooler full of block ice "sweats" a puddle of water when tucked when tucked away out of the breeze for a couple days, and that tells me something.

Gene, just a heads up about the Engel drop-in model. You might find this model easier to incorporate in your boat's interior. It's also quite easy to beef up the insulation around the outside of the box due to the square shape and right angles.

Engel Website

[Gene Neill]

Originally Posted by Copacabana

Gene, just a heads up about the Engel drop-in model. You might find this model easier to incorporate in your boat's interior. It's also quite easy to beef up the insulation around the outside of the box due to the square shape and right angles.

Engel Website

Hmm, interesting. That model is not listed on the US website. Up to .5A higher draw, but MUCH easier to insulate, since the compressor can be mounted remotely. I wonder which one comes out ahead in the real world.

[Copacabana]

Originally Posted by Gene Neill

Hmm, interesting. That model is not listed on the US website. Up to .5A higher draw, but MUCH easier to insulate, since the compressor can be mounted remotely. I wonder which one comes out ahead in the real world.

It's the same compressor as the 40 quart portable model, so the power consumption should be the same. If you insulate the drop-in model box, I believe the power draw should improve considerably. My next project is to add insulation around my Engel drop-in box.

These fridges (and all others, I suppose) sip power when you don't add warm things to the fridge or open the lid all day long. The reality is that people add beers to the fridge over the day, take stuff out and open the lid. I have found a way around this by adding beers to the fridge every day AFTER the batteries go to float and when the sun is still high enough that the panels are putting out 15+ amps. Then I turn the fridge to the max setting until I see the amps in from the panels going below 5a (at the end of the day). By then, everything is very cold and you can turn it back to the low setting. At bedtime you can just turn it off and it seems to keep everything cold until morning.

[john61ct]

Yes to tapping into free excess solar, but not the turning off overnight.

Doing that can increases total consumption.

[Copacabana]

Originally Posted by john61ct

Yes to tapping into free excess solar, but not the turning off overnight.

Doing that can increases total consumption.

That may be true, but I'm not so sure. I tend to turn the fridge back on when amps in are above the fridge consumption rate of 2.5a. The batteries are still at 12.6v and begin charging immediately (with the increasing amps in as the sun gets higher). I'll have to try both ways to see which is more efficient.