On Fri, 18 Jul 2008 18:14:20 +1000, Herodotus
wrote:

On Fri, 18 Jul 2008 12:06:49 +0700, Bruce in Bangkok
wrote:

On Fri, 18 Jul 2008 03:01:40 +0000, Larry wrote:

Herodotus wrote in
:

http://www.isotherm.com/en/product?f...1254FirefoxHTM
LShellOpenCommand

I've got a fridge in my truck about the size of a Cruise 85 running off the
shop inverter. It's made in Korea and cost $US89 from Home Depot on sale
in January of '06. What attracted me was the can dispensing rack in the
door. Has a tiny freezer that's near worthless but could keep some meat
solid. Ice trays freeze really fast.

What the hell makes a BOAT fridge the same size cost 10 times the price,
the $60 inverter screwed into the case?

What a rip.....boat crap!

Stop by. I have another one in the house....holding the Heineken's minikeg
to just the right temperature, right next to the computer desk....(c;

Larry, Larry, you just don;t understand. You see cheap Korean fridges
are sold by some bloke at Home Depot while proper YACHTING gear is
sold by gentlemen wearing white pants and those funny shoes with all
the squiggly cuts in the soles.

Obviously anything sold by a white pants salesman has got to be the
correct type of thing that a fellow would want on his boat whereas one
would rather be dead then to have the chaps know that he had a (Ug!)
Home Depot device aboard.

Besides, we were talking about built in fridges :-)

Bruce-in-Bangkok
(correct Address is bpaige125atgmaildotcom)

Larry, Bruce,

Gentlemen (My God! I have to lie sometimes to get what i want)

It does seem to me to be a lot of money to pay for the systems that
are sold. The problem is that I have a great wind generator (another
that can be added if necessary) an 80 watt solar panel (and will get
another) as well as a smart charge system for my 120 AMP alternator.

I have 4 Trojan 6 volt batteries in parallel and series - 440 Amp
hours. If necessary I could get another 2 of these but at the moment
don't think I need them.

I really want a system that will work well with minimal charging of
`the batteries by the alternator. I don't want one that I have to run
the motor for an hour each day just to run a fridge. I have noticed
that often the wind generator tops up the batteries and then feathers.
I hate to see potential charging going to waste especially if the wind
and sun fizzle out later in the day.

Well, first of all you need a "Larry Lesson" on how batteries charge
as your 110 amp alternator is just a waste of money.

Secondly, I have three 42.7 watt, old, solar panels and, God willing
the sun shines every day, they will keep MY 440 AH battery bank
charged and run my old 12 volt built in fridge. (providing I don't
turn on a light very often).

If you are going to hang about in Oz you may have enough wind to make
your wind generator useful but if you move up to Pinang they don't
work as well :-) Apparently they become indolent once they arrive in
Malaysia.

Now, there is a guy down the jetty that I just talked to, has a new
eutectic, built in, powered by a 12/220 volt compressor and tells me
that if the fridge is operated correctly (runs all the time; keep ice
on the plate; keep the fridge full; etc.) he gets buy with two solar
panels. I will get some details, panels, fridge model, etc., and let
you know as it sounds like what you want.

I am normally seldom moored to a dock and thus shore electricity is
not a factor. (BTW Herodotus isn't tethered either - in case either of
you make a smart arsed comment regarding my English useage).

What smartass? Moored - "hitched to a dock" We usually say "tied up"
where I come from, though.

The idea of a holding plate is that I could utilise periods of greater
charge whereas a conventional fridge runs off and on over the entire
day.

I do wonder why these systems are so expensive though. I can think of
a lot of things I could do with the dollars.

Now, now. To quote John D. Rockefeller, "If you have to ask how much
you can't afford one" :-)


Do you know if I can just buy the components separately or is there
something wrong with my logic?

If you get into seriously thinking of building a system I can probably
pick Stephan's brains for what, where and how much. It probably
wouldn't be cost effective to have him build the system as he is
oriented toward the high end of the market but he is a pretty friendly
guy and would probably tell me where he gets parts.

If you are thinking of building your own system beg, borrow or steal a
copy of the book by Nigal Calder "Refrigeration for Pleasure Boats:
Installation, Maintenance and Repair" as it has all the calculations
to plan insulation thickness, plate size, heat exchanger specs -
everything you wanted to know and more. Well worth the price.

BTW Bruce, I am due in KL on next Thursday night Inshahallah. Are you
still at Phuket? Apart from Penang, I am also visiting KL (Pelabuhan
Klang), Johor Baru, Singapore and Karimun and Medan in Sumatera. I
would love to make time to meet with you If I can. Don't worry. I
shall speak and listen slowly and can understand dull, boring, tedious
Southern drawl if required.

Can't make it this trip. I'm just out of the Yard and haven't even
been able to scrape the yard dirt off because it has been raining so
hard. As soon as I get that done I'm off to Bangkok for a couple of
weeks to my wife.

Have to be next trip.

I do appreciate both of your advice and your help.

regards
Peter

Bruce-in-Bangkok
(correct Address is bpaige125atgmaildotcom)

On Fri, 18 Jul 2008 18:32:48 +0700, Bruce in Bangkok
wrote:


Thanks Bruce,
This is the sort of information I am looking for.

It's a pity about the wind in that area. I always have to smile when I
see people hiring the Sunsail yachts out of Langkawi and then motoring
everywhere. Still, not a bad place to motor around the Islands and
then up to Siam.

In Curacao the trades blow non-stop. Even disconnected from the mains
and relying on the one 80 watt solar panel (16 years old) and the new
Airex wind generator, it keeps the batteries charged no matter my
usuage and the charging light goes off indicating a full charge quite
often during the day.

Need some of those trades back home.

cheers
Peter
On Fri, 18 Jul 2008 18:14:20 +1000, Herodotus
wrote:

On Fri, 18 Jul 2008 12:06:49 +0700, Bruce in Bangkok
wrote:

On Fri, 18 Jul 2008 03:01:40 +0000, Larry wrote:

Herodotus wrote in
m:

http://www.isotherm.com/en/product?f...1254FirefoxHTM
LShellOpenCommand

I've got a fridge in my truck about the size of a Cruise 85 running off the
shop inverter. It's made in Korea and cost $US89 from Home Depot on sale
in January of '06. What attracted me was the can dispensing rack in the
door. Has a tiny freezer that's near worthless but could keep some meat
solid. Ice trays freeze really fast.

What the hell makes a BOAT fridge the same size cost 10 times the price,
the $60 inverter screwed into the case?

What a rip.....boat crap!

Stop by. I have another one in the house....holding the Heineken's minikeg
to just the right temperature, right next to the computer desk....(c;

Larry, Larry, you just don;t understand. You see cheap Korean fridges
are sold by some bloke at Home Depot while proper YACHTING gear is
sold by gentlemen wearing white pants and those funny shoes with all
the squiggly cuts in the soles.

Obviously anything sold by a white pants salesman has got to be the
correct type of thing that a fellow would want on his boat whereas one
would rather be dead then to have the chaps know that he had a (Ug!)
Home Depot device aboard.

Besides, we were talking about built in fridges :-)

Bruce-in-Bangkok
(correct Address is bpaige125atgmaildotcom)

Larry, Bruce,

Gentlemen (My God! I have to lie sometimes to get what i want)

It does seem to me to be a lot of money to pay for the systems that
are sold. The problem is that I have a great wind generator (another
that can be added if necessary) an 80 watt solar panel (and will get
another) as well as a smart charge system for my 120 AMP alternator.

I have 4 Trojan 6 volt batteries in parallel and series - 440 Amp
hours. If necessary I could get another 2 of these but at the moment
don't think I need them.

I really want a system that will work well with minimal charging of
`the batteries by the alternator. I don't want one that I have to run
the motor for an hour each day just to run a fridge. I have noticed
that often the wind generator tops up the batteries and then feathers.
I hate to see potential charging going to waste especially if the wind
and sun fizzle out later in the day.

Well, first of all you need a "Larry Lesson" on how batteries charge
as your 110 amp alternator is just a waste of money.

Secondly, I have three 42.7 watt, old, solar panels and, God willing
the sun shines every day, they will keep MY 440 AH battery bank
charged and run my old 12 volt built in fridge. (providing I don't
turn on a light very often).

If you are going to hang about in Oz you may have enough wind to make
your wind generator useful but if you move up to Pinang they don't
work as well :-) Apparently they become indolent once they arrive in
Malaysia.

Now, there is a guy down the jetty that I just talked to, has a new
eutectic, built in, powered by a 12/220 volt compressor and tells me
that if the fridge is operated correctly (runs all the time; keep ice
on the plate; keep the fridge full; etc.) he gets buy with two solar
panels. I will get some details, panels, fridge model, etc., and let
you know as it sounds like what you want.

I am normally seldom moored to a dock and thus shore electricity is
not a factor. (BTW Herodotus isn't tethered either - in case either of
you make a smart arsed comment regarding my English useage).

What smartass? Moored - "hitched to a dock" We usually say "tied up"
where I come from, though.

The idea of a holding plate is that I could utilise periods of greater
charge whereas a conventional fridge runs off and on over the entire
day.

I do wonder why these systems are so expensive though. I can think of
a lot of things I could do with the dollars.

Now, now. To quote John D. Rockefeller, "If you have to ask how much
you can't afford one" :-)


Do you know if I can just buy the components separately or is there
something wrong with my logic?

If you get into seriously thinking of building a system I can probably
pick Stephan's brains for what, where and how much. It probably
wouldn't be cost effective to have him build the system as he is
oriented toward the high end of the market but he is a pretty friendly
guy and would probably tell me where he gets parts.

If you are thinking of building your own system beg, borrow or steal a
copy of the book by Nigal Calder "Refrigeration for Pleasure Boats:
Installation, Maintenance and Repair" as it has all the calculations
to plan insulation thickness, plate size, heat exchanger specs -
everything you wanted to know and more. Well worth the price.

BTW Bruce, I am due in KL on next Thursday night Inshahallah. Are you
still at Phuket? Apart from Penang, I am also visiting KL (Pelabuhan
Klang), Johor Baru, Singapore and Karimun and Medan in Sumatera. I
would love to make time to meet with you If I can. Don't worry. I
shall speak and listen slowly and can understand dull, boring, tedious
Southern drawl if required.

Can't make it this trip. I'm just out of the Yard and haven't even
been able to scrape the yard dirt off because it has been raining so
hard. As soon as I get that done I'm off to Bangkok for a couple of
weeks to my wife.

Have to be next trip.

I do appreciate both of your advice and your help.

regards
Peter

Bruce-in-Bangkok
(correct Address is bpaige125atgmaildotcom)

On Sat, 19 Jul 2008 09:46:57 +1000, Herodotus
wrote:

On Fri, 18 Jul 2008 18:32:48 +0700, Bruce in Bangkok
wrote:


Thanks Bruce,
This is the sort of information I am looking for.

It's a pity about the wind in that area. I always have to smile when I
see people hiring the Sunsail yachts out of Langkawi and then motoring
everywhere. Still, not a bad place to motor around the Islands and
then up to Siam.

In Curacao the trades blow non-stop. Even disconnected from the mains
and relying on the one 80 watt solar panel (16 years old) and the new
Airex wind generator, it keeps the batteries charged no matter my
usuage and the charging light goes off indicating a full charge quite
often during the day.

Need some of those trades back home.

cheers
Peter

(A bunch cut)

Following is information from the Catamaran Guy I mentioned.

Boat - 35 ft. Cat.
Engines - 2 X 3 cyl. Yanmar, standard Alternators (probably about 50
amp)
Solar Panels - 2 X 68 Watt (new Japanese) measured output 10.2 amps at
noon
Wind Generator - none
Fridge - Built in Eutetic, Fridge only
Insulation - Approx 7-8 cm. insulation, believe standard closed cell
foam
Compressor - Isotherm Classic Compact 12VDC/220VAC (uses inverter)
Condenser - Water cooled, 12VDC pump
Inverter - CLD Inverter, powers fridge and also acts as controller for
fridge system - owner says not used for boat power
Batteries - 3 X 120 AH = 360 AH
Water System - 12VDC pressure
Lights - All LED ------------------------------

Service:
4 day sailing trip: Ran engines as required, probably average of 3
hours per day, no problems with maintaining batteries at 90% or
higher.

At anchor: One week at anchor, did not run engines, ran fridge, radio,
lights, computer, etc., batteries never under 90% charge.

Comments:
Stephen, the fridge guy, feels that system is unduly complex with
water cooled condenser and inverter. Feels that straight 12VDC, air
cooled condenser, would be less trouble. Owner admits that had initial
problems with system, mainly electrical (inverter/controller).

Owner says on 4 day trip kept thermostat at 15 degrees C. Tries to
keep fridge full and ice on cold plate. Frequently charters bare boat
and says all charters have reported no problems with fridge.

Suggestions: Think that Stephen is right. Seems senseless to run 12VDC
through inverter to power 220 VAC compressor. Always some losses in
this type of system. Believe that air cooled condenser makes more
sense as personal experience shows that 12 VDC air cooled system works
in tropical climate and eliminates all the problems associated with
the water cooling system - pumps, clogging, etc.

If you need any more data let me know and I'll go down to Stephen's
shop and talk with him.

Do note the ALL LED lighting.

Bruce-in-Bangkok
(correct Address is bpaige125atgmaildotcom)

Bruce in Bangkok wrote in
news
Suggestions: Think that Stephen is right. Seems senseless to run 12VDC
through inverter to power 220 VAC compressor. Always some losses in
this type of system. Believe that air cooled condenser makes more
sense as personal experience shows that 12 VDC air cooled system works
in tropical climate and eliminates all the problems associated with
the water cooling system - pumps, clogging, etc.



Does someone make a 12VDC compressor? I've never seen one, here. I do see
AC inverters built into fridges driving standard AC-powered compressors
that have relays or electronics to switch to shore power if shore power is
available to run the compressor straight off shore power, however.

Inversion and synthsized AC power creation from battery power is now in the
range of 98-99% efficient with switching power supply technology using
pulse-width-modulation to accomplish a near-perfect sinewave output to
drive loads. These powerful synthesizers are very cheaply constructed and
very profitable.

The AC compressors synchronize to power line frequency (50 or 60 Hz), which
gives them a steady power output regardless of condensor pressure loading
which would drive a DC motor crazy trying to maintain counter EMF.

It makes little difference in efficiency running a switching inverter
outside......or building one inside for another $1500 to sell at the boat
store. The price difference is phenomenal!

On Sat, 19 Jul 2008 21:42:34 +0000, Larry wrote:

Bruce in Bangkok wrote in
news
Suggestions: Think that Stephen is right. Seems senseless to run 12VDC
through inverter to power 220 VAC compressor. Always some losses in
this type of system. Believe that air cooled condenser makes more
sense as personal experience shows that 12 VDC air cooled system works
in tropical climate and eliminates all the problems associated with
the water cooling system - pumps, clogging, etc.



Does someone make a 12VDC compressor? I've never seen one, here. I do see
AC inverters built into fridges driving standard AC-powered compressors
that have relays or electronics to switch to shore power if shore power is
available to run the compressor straight off shore power, however.

Inversion and synthsized AC power creation from battery power is now in the
range of 98-99% efficient with switching power supply technology using
pulse-width-modulation to accomplish a near-perfect sinewave output to
drive loads. These powerful synthesizers are very cheaply constructed and
very profitable.

The AC compressors synchronize to power line frequency (50 or 60 Hz), which
gives them a steady power output regardless of condensor pressure loading
which would drive a DC motor crazy trying to maintain counter EMF.

It makes little difference in efficiency running a switching inverter
outside......or building one inside for another $1500 to sell at the boat
store. The price difference is phenomenal!


I've got one. At least it says so on the can, Been tucked down under
the cockpit floor for ten years or more.

Bruce-in-Bangkok
(correct Address is bpaige125atgmaildotcom)

On Sat, 19 Jul 2008 21:42:34 +0000, Larry wrote:


The AC compressors synchronize to power line frequency (50 or 60 Hz), which
gives them a steady power output regardless of condensor pressure loading
which would drive a DC motor crazy trying to maintain counter EMF.

I don't think so - they are integrated induction motors and
compressors in a can. There's a capacitor that splits the phase, but
they slip the rotating field depending on load - if I recall

Brian W

Brian Whatcott wrote in
:

I don't think so - they are integrated induction motors and
compressors in a can. There's a capacitor that splits the phase, but
they slip the rotating field depending on load - if I recall

B

The capacitor lags the phase so you don't have to spin start them by
hand....they do run at the power line frequency....minus a little phase
slippage caused by the load.

Listen to one that has just started up and note its musical note. Notice
how the note hardly varies as the head pressure comes up to maximum, and
only the running current increases to maintain it.

Invented by Nikola Tesla, Father of Modern Electricity.

(I'm a fanboi...(c

If it had DC motors in it, those compressors would run like your universal
series wound vacuum cleaner or a drill/saw motor....varying widely in speed
as the load doubles/triples from idle.

The smooth steady hum of a compressor reeks of an AC induction motor,
capacitor start/capacitor run.

Larry wrote:

Does someone make a 12VDC compressor? I've never seen one, here.

You're pretty much admitting that you've never seen a custom marine
refrigeration system and know nothing about them. Most of the small
boat systems in the last 20 years have used DC Danfoss hermetic
compressors. The larger systems use a belt or direct drive from a DC motor.

I do see
AC inverters built into fridges driving standard AC-powered compressors
that have relays or electronics to switch to shore power if shore power is
available to run the compressor straight off shore power, however.

Perhaps the AC/DC units on powerboats do it this way.


Inversion and synthsized AC power creation from battery power is now in the
range of 98-99% efficient with switching power supply technology using
pulse-width-modulation to accomplish a near-perfect sinewave output to
drive loads. These powerful synthesizers are very cheaply constructed and
very profitable.

It can be done, but if you buy a general purpose inverter it will likely
run at about 80%,


The AC compressors synchronize to power line frequency (50 or 60 Hz), which
gives them a steady power output regardless of condensor pressure loading
which would drive a DC motor crazy trying to maintain counter EMF.

It makes little difference in efficiency running a switching inverter
outside......or building one inside for another $1500 to sell at the boat
store. The price difference is phenomenal!


OK, I just checked the energy efficiency of a GE compact fridge, 5.7
feet with a tiny freezer. It uses 360 kWh's a year, or 1 kWh per day.
Supplying this with an inverter would take over 100 AmpHours. However,
a similar sized fridge built with a small Danfoss will only use about 35
Amp-hours. My system includes this size fridge (bigger, actually), plus
a 5 foot deep freeze which keeps a summer's worth of burgers and steaks
at about 5 degrees only uses 55-60 AmpHours in New England, maybe 75-80
in the tropics. (Mine is a belt driven 12V compressor with holding
plates and water cooling. In the tropics, if I had to do it over, I'd
be considering two small Danfoss air-cooled systems, one for the fridge,
the other for the freezer.)

I'm a fan of faster charging, either with a high output alternator or a
Honda 2000i pushing a 100 Amp charger - either way I can do most of my
charging at 75-95 Amps, even though its only a 440 AH bank. But still,
adding 65 AH a day to save some money doesn't work, even assuming the GE
fridge would fit in a boat. Frankly the cost is irrelavent; there's no
way I would double my charging time to have less capacity. Since you're
claiming you can't charge at over 25 Amps, running the commercial fridge
would take an extra 2 and a half hours, and a system like mine would
require even more hours.

Of course, you're saying that a marine fridge *could be* built for on a
few dollars more than a commercial unit. Possibly true, but the market
is tiny by comparison, and that's what its all about.

jeff wrote in
:

1 kWh per day.
Supplying this with an inverter would take over 100 AmpHours.

1KWh at 13.8V = 72AH per day....1000/13.8V

Not much of a problem for a 330AH golf cart pair....

Larry wrote:
jeff wrote in
:

1 kWh per day.
Supplying this with an inverter would take over 100 AmpHours.

1KWh at 13.8V = 72AH per day....1000/13.8V

Not much of a problem for a 330AH golf cart pair....


So your golf cart batteries put out 13.8 Volts under load? Are they
those new 7 cell batteries? And send me one of the 100% efficient
invertors.

And as always, you're missing the real points. The important issue is
not having a big enough bank to run for one day (unless that's all the
time you're away from the dock), its recharging the batteries.

And of course for the two systems I compared, for the needs of a
cruiser, a 10 cubic foot system that includes a large deep freeze and
runs on 60 Amp-hours a day is vastly superior to 5.7 foot fridge with
tiny semi-freezer that takes 100 Amp-hours. Whether its worth the 10X
(or more) price difference is academic.