24 VDC appliances?
 

"misia" wrote in message
ail.from.there...
On my new boat I will have a powerfull 24VDC battery bank charged by a
diesel generator and auxiliary sources.

How powerful? Are you talking about a thousand amp-hours, or a hundred
thousand amp-hours? I can't imagin the cost, hassle and space rewquired for
the latter, but it is what you would need to provide what you are asking
about.


I did a bit of search but couldn't find much- are there any 24 VDC
appliances such as cooker/oven, fridge, AC and water heater you could
recommend?

In general, it is impracticle to use battery power for creating heat, i.e.,
stoves, ovens, water heaters, etc. It simply takes too much power for too
long to make it practical to store. Nevermind the voltage, it is more of an
issue of watt-hours.


I know I can run standard items through power inverter but I would
prefer not to do it for the sake of reliability/efficiency/cost.

Using the inverter, you have the reliability and cost of just one thing: the
inverter. After that, you can use very reliable and low cost 110 volt AC
appliances. To find 24 volt anything is going to be expensive, and the
bottom line is that DC motors are just not as reliable as AC motors, and
high current/low voltage is harder to work with (and thus less reliable)
than higher voltage/lower current.

I want
to go totally electric (no gas)

Then run your generator when you need the power, and use the batteries for
the small stuff.

A reasonable battery bank can run your lights, refrigerator, and through an
inverter you can run small appliances (such as a blender or short use of the
microwave), TV, stereo, computers, etc.

When looking for 24 volt equipment, take a look at commercial and "mega
yacht" sources. Lights shouldn't be a problem, but you may find that
electronics are scarce and very expensive. Since your battery bank is most
likely made up of a number of batteries in series, you could tap off a 12
volt line and have both a 12 volt and 24 volt system. Use the 24 volts for
the higher wattage stuff, such as the inverter, windlass and lights. Use
the 12 volts for the electronics, such as depth finders, VHF, etc.

Run the stove, water heater, and air conditioning off the generator.


Rod McInnis

24 VDC appliances?
 

"Larry W4CSC" wrote in message
...


I've never figured out why boats in cold climates waste all this
energy going out the exhaust. It's SO easy to make a cast iron heat
exchanger in a dry stack, right next to...or even right IN the exhaust
manifold that will just roast your ears with free heat.

the old Volkswagon Beetles used a heat exchanger off the exhaust manifolds
to heat the car! It was actually pretty nice on cold mornings, as the
heater worked almost instantly after starting the car.



We retrieve some of it with the hot water heater hooked to the water
jacket. Too bad so much heat is simply wasted.


There is a lot of free heat to be had from the engine. The only drawback is
that the engine has to be running! Not what you want when you are swinging
on the hook!

Rod McInnis

24 VDC appliances?
 

"Larry W4CSC" wrote in message
...


I've never figured out why boats in cold climates waste all this
energy going out the exhaust. It's SO easy to make a cast iron heat
exchanger in a dry stack, right next to...or even right IN the exhaust
manifold that will just roast your ears with free heat.

the old Volkswagon Beetles used a heat exchanger off the exhaust manifolds
to heat the car! It was actually pretty nice on cold mornings, as the
heater worked almost instantly after starting the car.



We retrieve some of it with the hot water heater hooked to the water
jacket. Too bad so much heat is simply wasted.


There is a lot of free heat to be had from the engine. The only drawback is
that the engine has to be running! Not what you want when you are swinging
on the hook!

Rod McInnis

24 VDC appliances?
 

Rod McInnis wrote:

When looking for 24 volt equipment, take a look at commercial and "mega
yacht" sources. Lights shouldn't be a problem, but you may find that
electronics are scarce and very expensive.

Most newbuild megayachts are equipped with very
comprehensive AC electrical generation, regulation, and
distribution systems.

The last large (165') yacht I sailed on was wired like most
of its class and used a wheelhouse mounted bank of batteries
to supply the electronics. That bank was float charged by a
charger mounted in the battery room. No one is going to run
DC supplies from a central location on a larger boat.
Depending on the certification standards a local emergency
supply is required in any event.

While I have not bothered to search, the selection of marine
equipment available in 24VDC must be very very small. Most
all little boats use 12VDC, most larger boats use
110/220/480VAC.

There used to be a pretty good selection of 32VDC stuff but
even then most heating was provided by burning fuel
directly. It strikes me as absurd to run a heating or
cooking system on DC unless it comes straight from a DC
generator and even then, nowadays, why bother.

There are several diesel fired heating boilers available for
hydronic heating that can be supplanted with waste heat when
the main propulsion is online or a genset when it's not.

The megayacht industry has developed some outstanding power
management systems but none of them include low voltage DC
for heating or cooking. It just isn't practical, even in
larger scale, and certainly not when you have to burn diesel
in a generator to charge a battery to supply an inverter to
heat a resistance coil to make heat.

Rick

24 VDC appliances?
 

Rod McInnis wrote:

When looking for 24 volt equipment, take a look at commercial and "mega
yacht" sources. Lights shouldn't be a problem, but you may find that
electronics are scarce and very expensive.

Most newbuild megayachts are equipped with very
comprehensive AC electrical generation, regulation, and
distribution systems.

The last large (165') yacht I sailed on was wired like most
of its class and used a wheelhouse mounted bank of batteries
to supply the electronics. That bank was float charged by a
charger mounted in the battery room. No one is going to run
DC supplies from a central location on a larger boat.
Depending on the certification standards a local emergency
supply is required in any event.

While I have not bothered to search, the selection of marine
equipment available in 24VDC must be very very small. Most
all little boats use 12VDC, most larger boats use
110/220/480VAC.

There used to be a pretty good selection of 32VDC stuff but
even then most heating was provided by burning fuel
directly. It strikes me as absurd to run a heating or
cooking system on DC unless it comes straight from a DC
generator and even then, nowadays, why bother.

There are several diesel fired heating boilers available for
hydronic heating that can be supplanted with waste heat when
the main propulsion is online or a genset when it's not.

The megayacht industry has developed some outstanding power
management systems but none of them include low voltage DC
for heating or cooking. It just isn't practical, even in
larger scale, and certainly not when you have to burn diesel
in a generator to charge a battery to supply an inverter to
heat a resistance coil to make heat.

Rick

24 VDC appliances?
 

Dear Rod,

I hear you. I absolutely agree on everything you said. The battery bank would be
15kWh capable AGM (for 100%50% discharge). There will be a 12V battery with
24V12V crosscharger.

I have found 90% efficient 5kW inverters in Taiwan for approx $600. M

Rod McInnis wrote:

"misia" wrote in message
ail.from.there...
On my new boat I will have a powerfull 24VDC battery bank charged by a
diesel generator and auxiliary sources.

How powerful? Are you talking about a thousand amp-hours, or a hundred
thousand amp-hours? I can't imagin the cost, hassle and space rewquired for
the latter, but it is what you would need to provide what you are asking
about.

I did a bit of search but couldn't find much- are there any 24 VDC
appliances such as cooker/oven, fridge, AC and water heater you could
recommend?

In general, it is impracticle to use battery power for creating heat, i.e.,
stoves, ovens, water heaters, etc. It simply takes too much power for too
long to make it practical to store. Nevermind the voltage, it is more of an
issue of watt-hours.

I know I can run standard items through power inverter but I would
prefer not to do it for the sake of reliability/efficiency/cost.

Using the inverter, you have the reliability and cost of just one thing: the
inverter. After that, you can use very reliable and low cost 110 volt AC
appliances. To find 24 volt anything is going to be expensive, and the
bottom line is that DC motors are just not as reliable as AC motors, and
high current/low voltage is harder to work with (and thus less reliable)
than higher voltage/lower current.

I want
to go totally electric (no gas)

Then run your generator when you need the power, and use the batteries for
the small stuff.

A reasonable battery bank can run your lights, refrigerator, and through an
inverter you can run small appliances (such as a blender or short use of the
microwave), TV, stereo, computers, etc.

When looking for 24 volt equipment, take a look at commercial and "mega
yacht" sources. Lights shouldn't be a problem, but you may find that
electronics are scarce and very expensive. Since your battery bank is most
likely made up of a number of batteries in series, you could tap off a 12
volt line and have both a 12 volt and 24 volt system. Use the 24 volts for
the higher wattage stuff, such as the inverter, windlass and lights. Use
the 12 volts for the electronics, such as depth finders, VHF, etc.

Run the stove, water heater, and air conditioning off the generator.

Rod McInnis

24 VDC appliances?
 

Dear Rod,

I hear you. I absolutely agree on everything you said. The battery bank would be
15kWh capable AGM (for 100%50% discharge). There will be a 12V battery with
24V12V crosscharger.

I have found 90% efficient 5kW inverters in Taiwan for approx $600. M

Rod McInnis wrote:

"misia" wrote in message
ail.from.there...
On my new boat I will have a powerfull 24VDC battery bank charged by a
diesel generator and auxiliary sources.

How powerful? Are you talking about a thousand amp-hours, or a hundred
thousand amp-hours? I can't imagin the cost, hassle and space rewquired for
the latter, but it is what you would need to provide what you are asking
about.

I did a bit of search but couldn't find much- are there any 24 VDC
appliances such as cooker/oven, fridge, AC and water heater you could
recommend?

In general, it is impracticle to use battery power for creating heat, i.e.,
stoves, ovens, water heaters, etc. It simply takes too much power for too
long to make it practical to store. Nevermind the voltage, it is more of an
issue of watt-hours.

I know I can run standard items through power inverter but I would
prefer not to do it for the sake of reliability/efficiency/cost.

Using the inverter, you have the reliability and cost of just one thing: the
inverter. After that, you can use very reliable and low cost 110 volt AC
appliances. To find 24 volt anything is going to be expensive, and the
bottom line is that DC motors are just not as reliable as AC motors, and
high current/low voltage is harder to work with (and thus less reliable)
than higher voltage/lower current.

I want
to go totally electric (no gas)

Then run your generator when you need the power, and use the batteries for
the small stuff.

A reasonable battery bank can run your lights, refrigerator, and through an
inverter you can run small appliances (such as a blender or short use of the
microwave), TV, stereo, computers, etc.

When looking for 24 volt equipment, take a look at commercial and "mega
yacht" sources. Lights shouldn't be a problem, but you may find that
electronics are scarce and very expensive. Since your battery bank is most
likely made up of a number of batteries in series, you could tap off a 12
volt line and have both a 12 volt and 24 volt system. Use the 24 volts for
the higher wattage stuff, such as the inverter, windlass and lights. Use
the 12 volts for the electronics, such as depth finders, VHF, etc.

Run the stove, water heater, and air conditioning off the generator.

Rod McInnis

24 VDC appliances?
 

"Rod McInnis" wrote in message
...

"Larry W4CSC" wrote in message
...


I've never figured out why boats in cold climates waste all this
energy going out the exhaust. It's SO easy to make a cast iron heat
exchanger in a dry stack, right next to...or even right IN the
exhaust
manifold that will just roast your ears with free heat.

the old Volkswagon Beetles used a heat exchanger off the exhaust
manifolds
to heat the car! It was actually pretty nice on cold mornings, as the
heater worked almost instantly after starting the car.

Are you insane? Suffering from Amnesia? We had one of those Beetles in
Minnesota from 1973 until 1985. My wife used to wonder why the other
people in the grocery store weren't wearing snowmobile suits. We
learned to drive one handed so we could scrape the inside of the
windshield with the other. Do you realize how long it takes to heat a
piece of cast iron and the sheet metal floorpan duct when it starts out
at zero, and the heat is coming from 750cc of motor (there were two, so
each only got half the exhaust)

Sheeesh.

del cecchi

24 VDC appliances?
 

"Rod McInnis" wrote in message
...

"Larry W4CSC" wrote in message
...


I've never figured out why boats in cold climates waste all this
energy going out the exhaust. It's SO easy to make a cast iron heat
exchanger in a dry stack, right next to...or even right IN the
exhaust
manifold that will just roast your ears with free heat.

the old Volkswagon Beetles used a heat exchanger off the exhaust
manifolds
to heat the car! It was actually pretty nice on cold mornings, as the
heater worked almost instantly after starting the car.

Are you insane? Suffering from Amnesia? We had one of those Beetles in
Minnesota from 1973 until 1985. My wife used to wonder why the other
people in the grocery store weren't wearing snowmobile suits. We
learned to drive one handed so we could scrape the inside of the
windshield with the other. Do you realize how long it takes to heat a
piece of cast iron and the sheet metal floorpan duct when it starts out
at zero, and the heat is coming from 750cc of motor (there were two, so
each only got half the exhaust)

Sheeesh.

del cecchi

24 VDC appliances?
 

"del cecchi" wrote in message
...

"Rod McInnis" wrote in message
...

"Larry W4CSC" wrote in message
...


I've never figured out why boats in cold climates waste all this
energy going out the exhaust. It's SO easy to make a cast iron heat
exchanger in a dry stack, right next to...or even right IN the
exhaust
manifold that will just roast your ears with free heat.

the old Volkswagon Beetles used a heat exchanger off the exhaust
manifolds
to heat the car! It was actually pretty nice on cold mornings, as the
heater worked almost instantly after starting the car.

Are you insane? Suffering from Amnesia? We had one of those Beetles in
Minnesota from 1973 until 1985. My wife used to wonder why the other
people in the grocery store weren't wearing snowmobile suits. We
learned to drive one handed so we could scrape the inside of the
windshield with the other. Do you realize how long it takes to heat a
piece of cast iron and the sheet metal floorpan duct when it starts out
at zero, and the heat is coming from 750cc of motor (there were two, so
each only got half the exhaust)

Sheeesh.

del cecchi


Can you say - southwind heater?
Who needs a passenger seat anyway?

Ahh - blessed warmth!

Mark Browne