Interesting Mac magazine article

[Sumner]

.....RE: Fridge. You may want to rethink this. It's a biggie. That inverter to run a house current fridge has many faults. Do the electrical math and you may find it will really chew up your batteries. The buzzing the of inverter may drive you nuts also.
We bought the same 12v Engel Fridge Sumner did. It was under $500 and works great. I have one 80w solar panel and it has kept it running for weeks now. Top loading also makes more sense on a boat as it keeps more cold inside. 12v fridge is really the way to go.....--Russ

I agree I think having an efficient 12 volt frig is for sure a biggie . We bought our Edge Star from these guys.....

http://www.compactappliance.com/FP630-S ... rc=FROOGLE

...... when they were just over $400 with free shipping on sale. The current $518 price is still a good one with free shipping for this size frig and it seems to be very efficient. I can't imagine that a 110 running through an inverter with it's losses is going to be even 1/4 as efficient and will probably use all of the 160 watts you have and maybe more.

We mounted ours....



...where it is easy for us to get to from the starboard seat in the 26S while preparing meals. It takes up less space than the two ......



....coolers it replaced and no more food floating in water. We feel we will probably pay for most of it in no ice bills over the next year or so and the most important aspect is the freedom it gives us on the water not having to plan our days around where and when we need to get ice next.

The other thing you might consider is making or they sell 12 volt generators that basically use a very efficient car alternator. I made one.....



http://purplesagetradingpost.com/sumner ... de-13.html

...and it has worked great. I'm hoping to run it less with the added panels, but still there will be times we need to top the batteries off and this does it quickly.

c ya,

Sum


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[Russ]

This fridge we got is 3' x 18 " with a small freezer .
It draws about 1 amp .87 by one spec sheet , 1.15 by another

Thats less than 150 watts , the two panels are 160 watts total , and the fridge , hopefully won't run all the time , so we ought to be able to cover it . That and the alternator on the motor .

It shouldn't be much of a load on a 500 watt inverter.

That's why I said you need to do the electrical math. My electrical math isn't great, but 160 watts at 110VAC is a lot fewer amps than at 12VDC. Your inverter running a 150 watt load is going to pull approx 15 amps DC. The solar panels only generate their max rating with the sun directly overhead unobscured. So in a perfect situation, 160 watts is 13 amps. But this situation rarely occurs. Realistically, you can expect 1/2 the rated output and for only 50% of the day. Inverting DC/AC is terribly inefficient. Plug your inverter in now and try it out to see if it can even start the fridge.

Then you have to consider that that fridge isn't meant to be efficient and probably has minimal insulation. As a minifridge, it expects AC power to be readily available and not an issue. Stick it in a hot cabin and it gets worse not to mention the fact that the heat coming off the compressor/condensor will add more heat to your cabin.

This thread goes into depth about 12v coolers and power considerations to keep food cool.


--Russ

[Seafarer]

This fridge we got is 3' x 18 " with a small freezer .
It draws about 1 amp .87 by one spec sheet , 1.15 by another
...
That's why I said you need to do the electrical math. My electrical math isn't great, but 160 watts at 110VAC is a lot fewer amps than at 12VDC. Your inverter running a 150 watt load is going to pull approx 15 amps DC.
--Russ

Correct. Typically for the same power (watts) you would multiple AC amp rating by 10 to get the apps at 12v DC (because 10 is approx 110v/12v). Your 1amp AC fridge would draw at least 10 amps DC (assuming you had a 100% efficient inverter, which does not exist). Chances are your DC draw will be higher, due to inverter losses.

Echoing the sentiments of other great contributors, I would recommend going with the Engel MT35 DC fridge.
Reasons:
1. It fits the Mac 26x cooler location almost perfectly,
2. It draws very little DC current, max 2.5amps DC at 12volts, but usually less (0.7 to 2.5amps). Max power draw is 30 watts, compared to your 150 watt (+ inverter loss) AC fridge.
3. It works great as a fridge (variable cool setting) and ALSO works great as a freezer (we left ours on the max setting for a short while and had ice forming in our drinks!)
4. Relatively very easy to install - simply cut ventilation holes in one end of the existing cooler fiberglass liner (there are some mods on this site that show this)

Here's a link for this fridge:
http://www.engel-usa.com/mt35.htm

More importantly:
For long term live-aboard, the difference between a 30 watt (max) fridge and a 150+ watt fridge is huge. Running at a full blast 100% duty cycle, over 24 hours, the energy usage difference between the two is about 240 amp-hours. At a more realistic 50% duty cycle, that is is still over 100 amp-hours, or the equivalent of running down TWO 105 amp-hour batteries EVERY day. You can greatly reduce your energy usage by making this simple choice. It will make a big difference re: your energy budget and charging needs

[kelseydo]

Gypsy,
I initially glossed over your post, and then picked up the July 2010 issue of Cruising World containing two articles on the Great Loop. I had been considering my X as a starter boat while thinking of selling the house in a few years to get a larger blue water boat. Now I wonder if your approach makes more sense. The X and M seem to be ideal Great Loop boats and the Great Loop looks be a great place to start. Please be generous with your posts, as I will not gloss over them again.
Way to go,
Dan

[KnottyOars]

Heartland boating is doing an article on Macs , think its the next issue .

I was interviewed for it , because of our plans to retire aboard ours , and why we chose a
to retire on.

Just read this thread. I think it's awesome. The wife and I just decided this month that we're going to live aboard a mac and do the Loop. As it stands, we're looking to have everything in place within the next 12 months. I'd really like to hear about your preparations as we will be following you down this road.
Thanks!

[Chinook]

Hi Knotty Oars,

We've seriously considered doing the Loop trip in our X, and actually hope to make this trip in a couple of years. I figure that allowing a full year for the circuit, keyed to the seasons, would be the ideal way to make the trip. I really hope you and your wife make the cruise, and post a journal of your experiences. It would be of great interest and value for those who follow. I'm wondering if you would do the trip with your sailing rig along, or leave it behind. I'm not sure how often it would be necessary to lower the mast for bridges and other barriers.

[Gypsy]

We do plan to post all along the way .
We started out with a ' 5 year plan' then I got laid off , and found another job that was suppose to last 2 years . So we changed to a ' 2 year plan'
That job ran out in 8 months AND Joanne found out she was getting laid off from the bank She works for, She gets laid off this Wednesday .

So now the plan is to sell the house , two of the cars ,( keep our tow/camper van ) and sell everything else we don't want , as soon as possible .

we have a vacant lot with a shipping container on it . We are going to keep it and use it for an address and store what we want in the cantainer .

Our immediate plans are , as soon after this Wednesday ,as possible , we are heading to Marine Liquidators in Fort Pierce Fl . here we plan to get what we can , to finish out fitting the boat.

After that , get the house ready to sell , get the boat ready to live aboard .
Depending on fast or slow the house sells we may look for jobs to tide us over while waiting.

Once we get on the boat we plan to stay in the Ala River , for a while to make sure the boat is good to go.

Then we begin the loop !

[Gypsy]

This fridge we got is 3' x 18 " with a small freezer .
It draws about 1 amp .87 by one spec sheet , 1.15 by another
...
That's why I said you need to do the electrical math. My electrical math isn't great, but 160 watts at 110VAC is a lot fewer amps than at 12VDC. Your inverter running a 150 watt load is going to pull approx 15 amps DC.
--Russ

More importantly:
For long term live-aboard, the difference between a 30 watt (max) fridge and a 150+ watt fridge is huge. Running at a full blast 100% duty cycle, over 24 hours, the energy usage difference between the two is about 240 amp-hours. At a more realistic 50% duty cycle, that is is still over 100 amp-hours, or the equivalent of running down TWO 105 amp-hour batteries EVERY day. You can greatly reduce your energy usage by making this simple choice. It will make a big difference re: your energy budget and charging needs

Wattage is wattage whether you raise or lower the voltage . A 30 watt unit would be substantially weaker than a 150 watt unit , no matter the voltage. 30 watts won't provide the same cooling as a 150 watt model.
A 150 watt 110 vac is the same same as 150 watt 12vdc except the amperage is higher on the DC side .
Running thru an inverter will add a few amps to the equation , or the DC draw .

On our Bayliner we have ran 110 vac fans that total up to about 150 watts . We run these thru a 700 watt inverter We run the fans all night and have battery the neaxt day , in fact we have stayed at anchor for two nights and not ran the motor in between , and the fans , and the one house battery do fine.

[LOUIS B HOLUB]

The above posts concerning folks with plans to do the "Great Loop" in a MacGregor Boat will be very interesting to follow, especially for us Mac'iers that desire to do the same (but unable to do so now).

I and my crew have done a "small" study, and folks that are doing, and have done, the Great Loop have many interesting adventures and stories. Our appeal toward the Great Loop is simply "seeing" America via a waterway, and not having to risk all the dangers of off shore waterways.

Here's hopes that postings and web sites occur concerning these Great Loop adventures with your MacGregor Boats -- It'll be fun for us to follow--and very interesting too.

[Sumner]

On the Great Loop has there been any more news on if it will be closed at Chicago? If it is with our boats you could take out and put back in pretty easily if there was a trailer handy. Any Mac owners by Chicago?

On the frig deal the 30 watt frigs are very efficient and you can actually turn them down below freezing and use them as a freezer if you need. If they can keep my food below 40 on 30-40 watts that is all I need.

I can't speak for Russ, but what I think he was saying is that the manufactures of boat/RV frigs are very aware of the need to be good yet work on the least amount of electricity, so a lot goes into making them do just that and there is a market out there for them. A bar/house frig is up against competition to keep the price as low as possible for sale in a Big Box Store so they might not be as energy efficient in keeping the food cold. With our limited options to produce electricity on a boat especially on a trip it probably is wise to buy the most efficient cooler possible.

Here is a pretty good link....

http://home.iprimus.com.au/rfh/portablefridges.html

....that I've posted in the past.

c ya,

Sum

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[sbods]

Great idea... good luck and best wishes!!

[Seafarer]

Wattage is wattage whether you raise or lower the voltage . A 30 watt unit would be substantially weaker than a 150 watt unit , no matter the voltage. 30 watts won't provide the same cooling as a 150 watt model.
A 150 watt 110 vac is the same same as 150 watt 12vdc except the amperage is higher on the DC side .
Running thru an inverter will add a few amps to the equation , or the DC draw .

Not quite so. Wattage is just the energy used. Cooling is quite a different thing.
You can think of cooling as Wattage x Efficiency. (Analogy: Think of fuel efficiency - takes a Chevy pickup truck four times as much fuel to get to the same destination as a Toyota Prius)
When designing a fridge, the priorities of the product spec determine what gets optimized. For AC fridges, priority is usually NOT efficiency - more like cost, or size/capacity, etc. For marine/RV fridges that will run on 12 volts, efficiency is very important.
You may be surprised to find that the "Cooling" you get from a 30 watt DC fridge optimized for power usage, is the same you would get from a 150 watt AC fridge, optimized for something else. I've used both, and my experience is that I have _MORE_ cooling from my 12v DC than my AC.

[MadMacX]

Anyone planning on doing the Great Loop should spend some time reading this blog about some folks that did it on 23' sailboat. The blog is arranged kind of backwards, but it is a very interesting read. I found it about a year ago and spent an afternoon reading it, from beginning to end. After reading their story I was ready to leave the next day.

http://pogopelli.blogspot.com/2006_10_01_archive.html

Pat

[Gypsy]

[/quote]

Not quite so. Wattage is just the energy used. Cooling is quite a different thing.
You can think of cooling as Wattage x Efficiency. (Analogy: Think of fuel efficiency - takes a Chevy pickup truck four times as much fuel to get to the same destination as a Toyota Prius)
When designing a fridge, the priorities of the product spec determine what gets optimized. For AC fridges, priority is usually NOT efficiency - more like cost, or size/capacity, etc. For marine/RV fridges that will run on 12 volts, efficiency is very important.
You may be surprised to find that the "Cooling" you get from a 30 watt DC fridge optimized for power usage, is the same you would get from a 150 watt AC fridge, optimized for something else. I've used both, and my experience is that I have _MORE_ cooling from my 12v DC than my AC.[/quote]


True , but like your analogy , a bigger car requires more energy. The fridge we have is a 3.5 cu ft .
Judging from the pictures , ours appears bigger than the one in the posted pictures . We looked at some smaller ones. To do what we need , we needed more cubic feet , than what we could afford in DC .
It appears to be well insulated . Its walls look to be as thick as the walls in the pictures that were posted. I may need to mount a small ' computer ' fan behind it to cool its condenser .

[DaveB]

Gypsy,
As I have stated in the past my 66 quart Edgestar freezer/cooler in day temps. of day 95 degrees and night at 78+ degrees with water temps 86 degrees.
I ran mine for 4 days with powering for 6 hrs. during the trip on my 10 amp max. Honda outboard and came back with 12.8 volts on duel 27 group deep cycle house batteries that ran everything.
I have done many cks on voltage and this unit draws around 4.6 amps just to start it than 2.2 amps running, the unit only runs every 15-20 min. and shuts off after running 5-10 min. This is in air Temps stated above. Thats on avarage 1 amp per hr. useing the highest figuares. Reality is I use aprox. much less and avarage 20-24 total amps per 24hr day useing all my elect. needs includeing frig.
We use it for all our food and water bottles. I have a 5 day Ice cooler for my Beer in settee locker. So nice to not haveing soggy food.
Do the math and this unit is much more efficiant than a Adler Barbor built in. tho the Adler Barbor has 6 cu. ft. refig. it also had high desity 4 inch insulation.
I paid around $450 with free shipping back a year ago and you have to put your ear down to unit to make sure it is running.
If one was to motor like doing the great loop, you would never notice amp draw. Also would run less due to cooler water and air temps.
Dave

Not quite so. Wattage is just the energy used. Cooling is quite a different thing.
You can think of cooling as Wattage x Efficiency. (Analogy: Think of fuel efficiency - takes a Chevy pickup truck four times as much fuel to get to the same destination as a Toyota Prius)
When designing a fridge, the priorities of the product spec determine what gets optimized. For AC fridges, priority is usually NOT efficiency - more like cost, or size/capacity, etc. For marine/RV fridges that will run on 12 volts, efficiency is very important.
You may be surprised to find that the "Cooling" you get from a 30 watt DC fridge optimized for power usage, is the same you would get from a 150 watt AC fridge, optimized for something else. I've used both, and my experience is that I have _MORE_ cooling from my 12v DC than my AC.[/quote]


True , but like your analogy , a bigger car requires more energy. The fridge we have is a 3.5 cu ft .
Judging from the pictures , ours appears bigger than the one in the posted pictures . We looked at some smaller ones. To do what we need , we needed more cubic feet , than what we could afford in DC .
It appears to be well insulated . Its walls look to be as thick as the walls in the pictures that were posted. I may need to mount a small ' computer ' fan behind it to cool its condenser . [/quote]