On Thu, 29 Jan 2009 21:54:02 -0500, "Eisboch"
wrote:


wrote in message
...
On Jan 29, 8:24 pm, "Eisboch" wrote:
wrote in message

...

If you have a small cabin on a boat can you get a small heat exchanger
that heats in winter and cools in summer that runs on 12 volts? What
kind of system would you use?

No.

Eisboch

So how do they air condition boats and campers?

My smart ass answer was because you said "runs on 12 volts". You would
have to have a battery bank the size of the boat to have enough amp capacity
to run a heater or air conditioner for very long. A small AC unit will draw
roughly 8 amps at 120 volts, so figure more than 10 times that using a 12
volt compressor (if they made one) or running it from a 12vdc to 120vac
inverter.

Generating enough heat BTU's would be a similar current draw. 12 volts is
simply unrealistic.

Air conditioners on boats or campers run from either 120 volts and in rare
cases, 220 volts.
The power is supplied from a genset or shore power.

Campers usually have either a heat strip in the AC unit and/or propane
heating systems.

Propane heat and maybe something like this for 12V A/C.
http://www.arcticbreeze-truckac.com/...eezeintro.html

But you're still going to need a genset for the A/C unless you have
120v service and an inverter.
Might be better/cheaper then to go with cheap 120v home window unit.
Larry has recommended these kind of setups and you can google his
solutions.
The Mac 26 forum had a number of guys installing A/C, and they all
went the shore power/genset 120v window unit route.
See what the ice-fishing guys uses to heat their ice shacks.
I know nothing about heat pumps, except the temp differentials often
make them non-cost effective.

--Vic

I hate to be simplistic or take the fun out of anyone's project,
but...

In the time it would take to read this thread, you could visit
http://www.go2marine.com/category.do?no=14018

Get a professional on the phone and order the right thing. If it were
my time and money I'd spend it paying an expert rather than on
becoming an expert myself.

AsianDoll

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On Jan 29, 10:40*pm, wrote:
On Jan 29, 10:08*pm, "Eisboch" wrote:





"Jim749293432" wrote in message

...

Eisboch wrote:

wrote in message
...
On Jan 29, 8:24 pm, "Eisboch" wrote:
wrote in message

...

If you have a small cabin on a boat can you get a small heat exchanger
that heats in winter and cools in summer that runs on 12 volts? What
kind of system would you use?

No.

Eisboch

So how do they air condition boats and campers?

My smart ass answer was because you said "runs on 12 volts". * You would
have to have a battery bank the size of the boat to have enough amp
capacity to run a heater or air conditioner for very long. *A small AC
unit will draw roughly 8 amps at 120 volts, so figure more than 10 times
that using a 12 volt compressor (if they made one) or running it from a
12vdc to 120vac inverter.

Generating enough heat BTU's would be a similar current draw. * 12 volts
is simply unrealistic.

Air conditioners on boats or campers run from either 120 volts and in
rare cases, 220 volts.
The power is supplied from a genset or shore power.

Campers usually have either a heat strip in the AC unit and/or propane
heating systems.

Eisboch

Heat pumps too.

Forgot that. *Reverse cycle combination AC and Heat. * But not for 12vdc.

Eisboch- Hide quoted text -

- Show quoted text -

Ok, so I need to run a generator, no problem, I have one. What's the
best way to go from there? I see a lot of stuff out there on Google,
any hints about configurations and brands.. I am much more concerened
with cooling than heating. Heating I can figure out later...- Hide quoted text -

- Show quoted text -

Ok, so I need to run a generator, no problem, I have one.

He's going to put the Generator in his rowboat.....lol.

"Vic Smith" wrote in message
...


wrote in message
...

If you have a small cabin on a boat can you get a small heat exchanger
that heats in winter and cools in summer that runs on 12 volts? What
kind of system would you use?

Propane heat and maybe something like this for 12V A/C.
http://www.arcticbreeze-truckac.com/...eezeintro.html

But you're still going to need a genset for the A/C unless you have
120v service and an inverter.
Might be better/cheaper then to go with cheap 120v home window unit.
Larry has recommended these kind of setups and you can google his
solutions.

The Mac 26 forum had a number of guys installing A/C, and they all
went the shore power/genset 120v window unit route.
See what the ice-fishing guys uses to heat their ice shacks.
I know nothing about heat pumps, except the temp differentials often
make them non-cost effective.

--Vic

I installed a residential, 10,000 BTU window AC unit in the
rear hatch of the Grand Banks we had. Kept the aft cabin nice and
comfortable for sleeping on hot, humid nights. Roughly 200 bucks,
including the marine plywood I bought to mount it in.
A marine AC unit, mounted in the engine room and ducted to the cabins was
quoted at about $6k to $8K by the guys at the marina. For the number of
times we needed AC up here, it wasn't worth the expense. Obviously, it was
used only when docked and when plugged into shore power, although I could
have run it while underway off the generator.

My current boat has two reverse cycle AC/heat units. The Navigator had
four of them. Marine types exchange using water rather than ambient air and
surprisingly, there is still enough heat in the ocean water up here during
the winter for them to produce enough heat to keep the boat nice and warm.
I usually shut them down and winterized them before the deep cold set in.
If I had stayed on the boat all winter, like some others do at our marina,
I'd would have used them throughout the entire winter. I know a few people
that live on their boats year-round at the marina and they have told me that
there is only about a 2 week period in the middle of the winter when they
have to supplement the heat pumps with some electric space heaters.

Eisboch

wrote in message
...
I hate to be simplistic or take the fun out of anyone's project,
but...

In the time it would take to read this thread, you could visit
http://www.go2marine.com/category.do?no=14018

Get a professional on the phone and order the right thing. If it were
my time and money I'd spend it paying an expert rather than on
becoming an expert myself.

AsianDoll


What "thing"?

I didn't see any air-conditioning systems or heaters that run on 12 volts
there.

Eisboch

On Fri, 30 Jan 2009 04:52:40 -0500, "Eisboch"
wrote:



My current boat has two reverse cycle AC/heat units. The Navigator had
four of them. Marine types exchange using water rather than ambient air and
surprisingly, there is still enough heat in the ocean water up here during
the winter for them to produce enough heat to keep the boat nice and warm.
I usually shut them down and winterized them before the deep cold set in.
If I had stayed on the boat all winter, like some others do at our marina,
I'd would have used them throughout the entire winter. I know a few people
that live on their boats year-round at the marina and they have told me that
there is only about a 2 week period in the middle of the winter when they
have to supplement the heat pumps with some electric space heaters.

Didn't know they were that good.
You ever look at the efficiency trade-offs at different temps?
Like when it's more efficient to use the space heater, even though the
pump can do the job.
I wonder if those motel thru-wall units are heat pumps. Had to turn
the heat on in one of the motels on the way to Florida last year, and
I just assumed it had heat coils. But maybe not.
From what I've read it's too cold up here to make heat pumps a frugal
investment.

--Vic

"Vic Smith" wrote in message
...

On Fri, 30 Jan 2009 04:52:40 -0500, "Eisboch"
wrote:



My current boat has two reverse cycle AC/heat units. The Navigator had
four of them. Marine types exchange using water rather than ambient air
and
surprisingly, there is still enough heat in the ocean water up here during
the winter for them to produce enough heat to keep the boat nice and warm.
I usually shut them down and winterized them before the deep cold set in.
If I had stayed on the boat all winter, like some others do at our marina,
I'd would have used them throughout the entire winter. I know a few
people
that live on their boats year-round at the marina and they have told me
that
there is only about a 2 week period in the middle of the winter when they
have to supplement the heat pumps with some electric space heaters.

Didn't know they were that good.
You ever look at the efficiency trade-offs at different temps?
Like when it's more efficient to use the space heater, even though the
pump can do the job.
I wonder if those motel thru-wall units are heat pumps. Had to turn
the heat on in one of the motels on the way to Florida last year, and
I just assumed it had heat coils. But maybe not.
From what I've read it's too cold up here to make heat pumps a frugal
investment.

--Vic

Some of the reverse cycle heat pumps have strip heaters also. I suspect
hotel types use strip heaters in the heat mode. One of the units on the
Navigator was equipped with heaters. You could program it to run using the
compressor in the reverse cycle mode or using the heat strip.

The water based systems seem to run pretty well down to water temps of 40
degrees, then start to lose ground if the water temp goes lower. They will
still extract heat, but not as efficiently.

Obviously, an air exchange system won't work with air temps even higher.
Our pool heater has an interlock to prevent it from running if the ambient
air temp drops to about 45 degrees or less.
If it continued to run, it would simply ice up the evaporator.

Eisboch

On Thu, 29 Jan 2009 19:40:55 -0800 (PST),
wrote:

On Jan 29, 10:08*pm, "Eisboch" wrote:
"Jim749293432" wrote in message

...





Eisboch wrote:

wrote in message
...
On Jan 29, 8:24 pm, "Eisboch" wrote:
wrote in message

...

If you have a small cabin on a boat can you get a small heat exchanger
that heats in winter and cools in summer that runs on 12 volts? What
kind of system would you use?

No.

Eisboch

So how do they air condition boats and campers?

My smart ass answer was because you said "runs on 12 volts". * You would
have to have a battery bank the size of the boat to have enough amp
capacity to run a heater or air conditioner for very long. *A small AC
unit will draw roughly 8 amps at 120 volts, so figure more than 10 times
that using a 12 volt compressor (if they made one) or running it from a
12vdc to 120vac inverter.

Generating enough heat BTU's would be a similar current draw. * 12 volts
is simply unrealistic.

Air conditioners on boats or campers run from either 120 volts and in
rare cases, 220 volts.
The power is supplied from a genset or shore power.

Campers usually have either a heat strip in the AC unit and/or propane
heating systems.

Eisboch

Heat pumps too.

Forgot that. *Reverse cycle combination AC and Heat. * But not for 12vdc.

Eisboch- Hide quoted text -

- Show quoted text -

Ok, so I need to run a generator, no problem, I have one. What's the
best way to go from there? I see a lot of stuff out there on Google,
any hints about configurations and brands.. I am much more concerened
with cooling than heating. Heating I can figure out later...

Scotty, this would probably be a good place to start. These guys make most
of the A/C units you see on top of campers.

http://www.dometic.com/enus/Americas...for-your-boat/

or: http://tinyurl.com/d7aosz
--
John H

For a great time, go here first... http://tinyurl.com/d3vxvm

* Definition of a teenager?
God's punishment...for enjoying sex. *

wrote:
On Jan 29, 10:08 pm, "Eisboch" wrote:
"Jim749293432" wrote in message

...





Eisboch wrote:
wrote in message
...
On Jan 29, 8:24 pm, "Eisboch" wrote:
wrote in message
...
If you have a small cabin on a boat can you get a small heat exchanger
that heats in winter and cools in summer that runs on 12 volts? What
kind of system would you use?
No.
Eisboch
So how do they air condition boats and campers?
My smart ass answer was because you said "runs on 12 volts". You would
have to have a battery bank the size of the boat to have enough amp
capacity to run a heater or air conditioner for very long. A small AC
unit will draw roughly 8 amps at 120 volts, so figure more than 10 times
that using a 12 volt compressor (if they made one) or running it from a
12vdc to 120vac inverter.
Generating enough heat BTU's would be a similar current draw. 12 volts
is simply unrealistic.
Air conditioners on boats or campers run from either 120 volts and in
rare cases, 220 volts.
The power is supplied from a genset or shore power.
Campers usually have either a heat strip in the AC unit and/or propane
heating systems.
Eisboch
Heat pumps too.
Forgot that. Reverse cycle combination AC and Heat. But not for 12vdc.

Eisboch- Hide quoted text -

- Show quoted text -

Ok, so I need to run a generator, no problem, I have one. What's the
best way to go from there? I see a lot of stuff out there on Google,
any hints about configurations and brands.. I am much more concerened
with cooling than heating. Heating I can figure out later...


Don't forget to place that generator properly in the cabin and aim its
exhaust towards your face.

On Jan 30, 6:31*am, "Eisboch" wrote:
"Vic Smith" wrote in message

...





On Fri, 30 Jan 2009 04:52:40 -0500, "Eisboch"
wrote:

My current boat has two reverse cycle AC/heat units. * The Navigator had
four of them. *Marine types exchange using water rather than ambient air
and
surprisingly, there is still enough heat in the ocean water up here during
the winter for them to produce enough heat to keep the boat nice and warm.
I usually shut them down and winterized them before the deep cold set in.