Hot water, heaters, cookers.....

[Willallison]

Thought this topic deserved its own thread.......

With a little ingenuity I think we could engineer O-1 to accept a number of heating / water / cooking alternatives.

Much has been written about the advantages of using a diesel / parafin etc type of cooker / heater. The biggest problem (apart from cost) with this type of system is that if you also want to use it to produce hot water, then you are stuck with 'having the heater on' at the same time. That's ok if you only cruise when it's cold - but ask Paul if he'd like a furnace running in the corner of his cabin right now......
I think those systems are terrific for certain applications - so O-1 could be designed to accept such a system.

For a number of reasons - simplicity, light weight and cost to name just 3 - many would choose to simply use a portable single burner stove, take a portable heater if it looked like being cold, and leave the showers till you get ashore. It should be very easy to ensure O-1 could fit this bill.

Some would like the instant heat provided by gas (LPG, proane etc). A tankless water heater, cooker and maybe an LPG fueled heater.......
We'd nee to ensure that O-1 could be built with a suitable storage locker and a few other things - no reason why it couldn't be done.....

Then there's the mini-live-aboard option which is in the early stages of gestation in my mind....
A small, lightweight, very quiet petrol engined generator capable of runninging a tankless water heater, or an immersion water heater, a space heater, fridge etc etc etc
A well insulated locker, a few wires and there it is! No need to call in to the dock 'till it's time to come home.

Given that O-1 is intended to appeal to a wide variety of people, with a wide variety of needs, wants and opinions, it makes sense to try (where possible and sensible) to appeal to all their requirements.

[Willallison]

Alas I must consign myplans for the (almost) self reliant mini cruiser to the scrap heap:(
A little more research and a little more maths leads me to the conclusion that electricity (courtesy of a small generator) is not the way to go. Assuming you like your showers at around 42C and your water starts off at around 10C then you will need a rise in temp of about 30C (54F). A frugal shower uses about 1 gpm.

Westmarine offer an electric tankless heater for US$239. When you look at the Eemax site, you see that their most powerful model requires 3.5kW and can produce a heat rise of only 24F at 1gpm. Almost all the other systems I found uses 10's of kW. So you would require a HUGE genset to cope with the power draw. One alternative is to use a smaller generator and run the system via batteries and an inverter. Once again, you would require so much battery capacity, that the weight would be a killer.
I thought I had found a solution when I came across the Ariston point of use system http://www.electricwaterheaters.com/ariston/index.htm
but when you look closely, you see that using the 6gallon unit you would need to run a generator for 1/2 an hour for every 5 minute shower....not a very efficient use of power when you can flick the switch and get instant hot water with LPG......

So, what of all the other advantages of having mains power at your finger tips - like battery charging etc. - well Honda produce a number of little generators which could still be of some use aboard a boat like O-1. Models like this http://www.hondampe.com.au/Hondampe/splitter.htm?post=~hondampe~power~range~generators~mpedefault.htm?chan=~hondampe~power~range~generators~ only weigh 13kg.....

So, for me at least, my first choice would be gas (LPG) - cooker, hw and heating too perhaps. Closely followed by diesel, using something like the Webasto coolant heater http://www.suremarine.com/body.html . Expensive - but good.

[Portager]

Originally posted by ErikG
Here in scandinavia the preferred stoves are either LPG or Alcohol with diesel on a distant third. LPG is by far the most used, a well installed LPG system works fine but personally I don't like it that much. Alcohol as on the Origo stoves (http://www.origo-sweden.com/default.htm) is a nice alternative currently only used for stoves and mostly onboard smaller boats.

I'm thinking about an idea to use an "Origo like" heater for water heating, that could be used for either hotwater as such or cabin heat. So far I have yet to find anyone that uses alcohol heaters for this purpose. There might be a perfectly good answer to why, but it ought to work... <snip> Any comments?

ErikG;

Please don't take this personally, but here is my opinion.

If you read the article that I provided a link to earlier http://www.uaf.edu/seagrant/boatkeeper/boat-heat.pdf you will see that Terry Johnson says, "Kerosene, white gas, and alcohol portable heaters are sometimes sold for marine use. They are non-vented, and the exhaust is open and introduces water vapor to the living space. If the space is not adequately ventilated this can cause oxygen depletion and carbon monoxide poisoning. These portable heaters have no place on an enclosed boat."

The reason that so many people choose these options is not because they are safer, but because they are cheaper (and all to often the consumers are uninformed of the safety dangers). One of the main cost differences that separate low cost systems from some higher cost systems is the cost to confining combustion within a combustion chamber and vent the exhaust gases to the outside. The intelligent shopper will study the options and then choose the level of safety they can afford. In my case, I will have a diesel powered boat and I'll use water jacket heat and waste heat from the exhaust for Hydronic heat and a diesel stove. For O-1, my engineering opinion is that Hydronic diesel heat and a diesel stove would be the safest. I am still evaluating low cost alternatives. So far I have not found an alternative with sufficiently lower cost to justify the safety reduction.

Originally posted by Willallison
<snip>Much has been written about the advantages of using a diesel / paraffin etc type of cooker / heater. The biggest problem (apart from cost) with this type of system is that if you also want to use it to produce hot water, then you are stuck with 'having the heater on' at the same time. That's ok if you only cruise when it's cold - but ask Paul if he'd like a furnace running in the corner of his cabin right now...... I think those systems are terrific for certain applications - so O-1 could be designed to accept such a system.

Perhaps I should clarify a distinction here. The hot water options are usually available on a stove, which is insulated from the cabin. Some heat still escapes and heats the cabin, but not nearly as much as if the water coil were in a heater, which is intended to heat the cabin. You can also install a water heater coil in the heater if you want to use both in the winter, but you would only use the stove in the summer.

The water heater for the Hydronic systems are generally located in the engine room or non-occupied spaces so you can heat water in the summer without heating the interior of the boat.

For a number of reasons - simplicity, light weight and cost to name just 3 - many would choose to simply use a portable single burner stove, take a portable heater if it looked like being cold, and leave the showers till you get ashore. It should be very easy to ensure O-1 could fit this bill.

Lets also add safety to the list. Portable stoves are acceptable if they are secured and used in the aft cockpit or with good ventilation. They should not be relied on for heat because when you have adequate ventilation you get very little heat. Conversely, if you are getting good heat you don't have enough ventilation.

Hot Camp Showers http://www.hotcampshowers.com/index.html (this link was not working when I tested it today, but it worked yesterday so it is probably a temporary outage) has a campfire water heater which is just a cooper coil with a long handle that you lay in a camp fire. With a little experimentation, you could probably make a water heater coil for a portable stove. I would rig up a loop of hot water hose connected to a conical coil of copper tubing in an area of the cockpit where the stove could be secured. Make sure that you provide a mixing valve down stream of the heat loop to provide temperature control.

Some would like the instant heat provided by gas (LPG, propane etc). A tankless water heater, cooker and maybe an LPG fueled heater.......
We'd nee to ensure that O-1 could be built with a suitable storage locker and a few other things - no reason why it couldn't be done.....

I think the diesel heater and diesel stove are a better option. I have not found a cost advantage to propane yet, so why compromise safety?

Then there's the mini-live-aboard option which is in the early stages of gestation in my mind....
A small, lightweight, very quiet petrol engined generator capable of runninging a tankless water heater, or an immersion water heater, a space heater, fridge etc etc etc
A well insulated locker, a few wires and there it is! No need to call in to the dock 'till it's time to come home.

Why does it have to be petrol?

To run most electric water heaters would require about a 2.5 KW generator, but since most people don't want to shut everything else off you would probably need about 5 KW. A much more efficient approach is to mount a heat exchanger on the generator exhaust like this http://www.polarpowerinc.com/products/heat_exchanger/heat_exchanger.htm . In general most engines convert 1/3 of the energy released by burning fuel into mechanical energy, 1/6 of the energy goes into the water jacket and 1/2 of the energy goes out the exhaust. Typical air to water heat exchangers are about 67% efficient so you can recover 2/3 of 1/2 or an amount equal to the output of the engine. So with a 2.5 KW generator and an exhaust heat exchanger you can get 2.5 KW of electrical power and 2.5 KW of heat.

An even more efficient approach would be to put a large alternator and an exhaust heat exchanger on the main engine. :)

Given that O-1 is intended to appeal to a wide variety of people, with a wide variety of needs, wants and opinions, it makes sense to try (where possible and sensible) to appeal to all their requirements.

Why didn't this principal apply to diesel and petrol engines?

Cheers;
Mike Schooley

[Portager]

Originally posted by Willallison
So, what of all the other advantages of having mains power at your finger tips - like battery charging etc. - well Honda produce a number of little generators which could still be of some use aboard a boat like O-1. Models like this http://www.hondampe.com.au/Hondampe/splitter.htm?post=~hondampe~power~range~generators~mpedefault.htm?chan=~hondampe~power~range~generators~ only weigh 13kg.....

A college of mine once did a demonstration of our system for a military customer. The electrical power on the customers boat was too unreliable to run our system (they had brown-outs when high power loads kicked in which caused our computers to reset). His solution was to go out and purchase a portable generator and strap it on the aft deck. The customer vetoed the gasoline (petrol) generator, but he agreed to a diesel generator. Things were going swimmingly until we cleared the break water. About a 1/4 mile out somebody noticed that the aft deck was on fire. Turned out that the portable generator fuel tank wasn't splash proof. It splashed fuel on the deck and something ignited it. Fortunately the customers boat was aluminum and all the fire did was scorch the paint so we got off the hook. The moral I came away with was if it wasn't designed for marine use be very careful using it in a marine application.

[i]So, for me at least, my first choice would be gas (LPG) - cooker, hw and heating too perhaps. Closely followed by diesel, using something like the Webasto coolant heater http://www.suremarine.com/body.html . Expensive - but good. [/B]

My research indicated that the Takagi is the best quality propane tankless water heater and the only one recommend for Hydronics. It sells for $1497.00 compared to the Webasto at US $1,750 or a $253 cost difference. The propane system requires a propane sniffer at US ~$225 so the cost difference is US $28. You still need a propane locker and propane tanks. Where is the cost savings?

I did find the Poloma tankless propane water heater only costs US $340, but I also found references on the live aboard list that indicated that their surveyor flagged it as a safety risk and their insurance company made them remove it.

Cheers;
Mike Schooley

[Willallison]

My research indicated that the Takagi is the best quality propane tankless water heater and the only one recommend for Hydronics. It sells for $1497.00 compared to the Webasto at US $1,750 or a $253 cost difference. The propane system requires a propane sniffer at US ~$225 so the cost difference is US $28. You still need a propane locker and propane tanks. Where is the cost savings?

Mike, I simply use the Webasto as a well known example of the type - the Takagi may indeed be a better unit. But check out the Webasto Thermo 90S - it is a hydronic unit and would fit the bill nicely.

The reason that so many people choose these options is not because they are safer, but because they are cheaper

I use a methylated spirits cooker (and heater) on my boat. I use it precisely because it is safe - any spills, leaks etc that result in fire can simply be extinguished with water - try that with diesel and you'll do nothing but spread it. The by-product of its combustion is water (plus a little CO2), so there is no CO problem.

Conversely, if you are getting good heat you don't have enough ventilation.

Terry Johnson also states that "there is more to keeping a boat warm and dry than just producing heat. Porper air flow through all the spaces of a boat helps distribute heat, remove moisture...."
I always ensure that I have a little ventilation when I'm cooking or heating for exactly this reason.

think the diesel heater and diesel stove are a better option. I have not found a cost advantage to propane yet, so why compromise safety?

Diesel stoves have a nasty reputation for making your food taste like fuel.....what more reason could you want?

Why does it have to be petrol?

To run most electric water heaters would require about a 2.5 KW generator

You need a great deal more than 2.5kW to run a tankless system. The Eemax system I referred to in an earlier post is simply not up to the job - most of the domestic systems I looked at used about 28kW - that's a bloody big generator!
A 2.5kw generator needs to operate for at least 1/2 and hour in order to heat enough water for 1 five minute shower using an immersion heater. No matter how you do it, it simply isn't an efficient means of getting hot water - better to go the diesel or gas route.
I only looked at petrol generators because the fuel supply was already on board - plus they tend to be quieter, cheaper to buy and lighter.

Why didn't this principal apply to diesel and petrol engines?

For me, it always has - but designing a boat to accept two different types of cookers is a whole lot different to designing one to accept both shaft drive diesel and outboard propulsion!

As I said before - we all have our views on the best way to go about getting hot water, heat and food. This should be one area where we can all be accomodated. Rather than arguing about which is the best way, lets come up with a design which will allow us to install the system of our choice.....

[Portager]

Originally posted by Willallison

Mike, I simply use the Webasto as a well known example of the type - the Takagi may indeed be a better unit. But check out the Webasto Thermo 90S - it is a hydronic unit and would fit the bill nicely.

???The Webasto Thermo 90S is an excellent diesel heater. We have both recommended it. The Takagi is an excellent propane heater.

I use a methylated spirits cooker (and heater) on my boat. I use it precisely because it is safe - any spills, leaks etc that result in fire can simply be extinguished with water - try that with diesel and you'll do nothing but spread it. The by-product of its combustion is water (plus a little CO2), so there is no CO problem.

The risk of diesel spill for permanently plumbed systems is nonexistent, except at the fill spout where there isn't an igntion source. The main issue with methylated spirits cooker is the consumption of oxygen and the production of water. For every pound on fuel burned you produce 7 pounds of water.

Terry Johnson also states that "there is more to keeping a boat warm and dry than just producing heat. Porper air flow through all the spaces of a boat helps distribute heat, remove moisture...."
I always ensure that I have a little ventilation when I'm cooking or heating for exactly this reason.

I think you made my point very well. If the combustion is confined, combustion air is drawn from outside and all exhaust products are vent overboard then the interior oxygen is not depleted and the water vapor isn't a problem, therefore ventilation requirements are reduced and the efficiency of the system is greatly improved.

Diesel stoves have a nasty reputation for making your food taste like fuel.....what more reason could you want?

I think you have confused diesel stove with the old pressurized kerosene stoves. The diesel stoves I am talking about have a sealed combustion chamber and the heat is conducted into the heating plate. Combustion air comes from outside and all exhaust products go outside. These units do not have a reputation for making your food smell like fuel. They do have a reputation for being the safest and most efficient stove available. There is also a lot of erroneous information and misconceptions regarding them. The only valid complaints I know of is they take longer to heat up than a propane stove.

You need a great deal more than 2.5kW to run a tankless system. The Eemax system I referred to in an earlier post is simply not up to the job - most of the domestic systems I looked at used about 28kW - that's a bloody big generator!
A 2.5kw generator needs to operate for at least 1/2 and hour in order to heat enough water for 1 five minute shower using an immersion heater. No matter how you do it, it simply isn't an efficient means of getting hot water - better to go the diesel or gas route.
I only looked at petrol generators because the fuel supply was already on board - plus they tend to be quieter, cheaper to buy and lighter.

I was trying to be nice. If the water is heated by waste heat and stored in an insulated container you can accumulate heat over the day and use it as required. 1 hour of generator operation per day (plus some margin for heat loss) would be sufficient for 2 showers. It will take more than an hour per day to recharge the battery bank.

For me, it always has - but designing a boat to accept two different types of cookers is a whole lot different to designing one to accept both shaft drive diesel and outboard propulsion!

What about gas and diesel stern drives. A duo-prop stern drive provides 10% to 15% more thrust than a single prop, so a 135 HP to 140 HP duo-prop stern drive equals a 150 HP outboard. The 135 HP gas stern drive is lower cost than a 150 HP outboard and you get heat and electrical power very economically. In addition the buyer/builder has the option of using diesel.

As I said before - we all have our views on the best way to go about getting hot water, heat and food. This should be one area where we can all be accommodated. Rather than arguing about which is the best way, lets come up with a design which will allow us to install the system of our choice.....

I am trying very hard to make the selected system work, but I don't think most people fully understand the impact that choosing an outboard has on the rest of the system. I said a long time ago that we need to add the cost of the water heater to the cost of the outboard to compare it to the inboard. Now we know that with either the propane or diesel tankless water heater will cost >$3,000 US. Did we make the right choice?

Cheers;
Mike Schooley

[Willallison]

Ok, if diesel is the best cooker and Webasto / Takagi both make excellent heater / hot water systems, then for those who choose this option, the cost would be similar regardless of engine type. And if you want hot water and space heating on demand (without running an engine) then the options are still the same.
I, for instance, wouldn't install a Webasto system, because I couldn't justify the cost. I'd have something like a Bosch LPG tankless heater (for about $400) and a small 2-burner stove. I wouldn't install an oven in a boat the size of O-1 and I'd rather use my BBQ out the back anyway. My experience is that the little metho heater I already have (<$100 US) does an excellent job, so I wouldn't bother going to the expense of an all out, plumbed in system. Yes it creates moisture so I need to ventilate more than would otherwise be necessary, but it gives out so much heat that it doesn't matter.

I'm not saying that this is the best or only option for everyone - quite the opposite in fact - as I said before O-1 should be engineered to accept all the feasable cooking and heating options.

I was trying to be nice. If the water is heated by waste heat and stored in an insulated container you can accumulate heat over the day and use it as required. 1 hour of generator operation per day (plus some margin for heat loss) would be sufficient for 2 showers. It will take more than an hour per day to recharge the battery bank.

That's exactly what I said - you'd need to run a generator for at least an hour in order to have two showers. Therefore, regardless of type, a tankless sytem is a more efficient way of doing it. Granted, if you're running a generator (with sufficient capacity) anyway, then you might as well be using it to heat water.
As far as needing to run for more than an hour a day to maintain battery charge goes, I guess it really depends on how you use your electricity and on your batteries. I have two semi-deep cycle batteries on my boat. Essentially I use one as both the house and starting battery and keep the other as a 'spare'. In five years of cruising I've only once been without battery power (alternator wasn't working correctly). On a daily basis I would average about 30 minutes running, but on occaisions I have remained at anchor for 2 - 3 days (this has necessitated the use of my 'spare' to start the motor so as not to completely destroy the house battery) Without the quite high drain electric fridge that I have on board, I could comfortably go longer.
I have also found that I need to run for at least 30 minutes in order to heat my water enough for a shower. But of course, it doesn't stay hot for very long, so am restricted to showering just after going somewhere - not always when I want my shower. I've also regularly just gone for a raz for 1/2 an hour in order to heat the water up - and I can tell you, that definitely isn't the most efficient way to heat water!:D

Choosing outboards does have ramifications as far as hot water goes. You can't simply use excess heat to create stored hot water. But for about the same cost as a decent heat exchange type hot water cylinder, you can have an LPG tankless heater which is able to provide instant hot water on demand. I don't see that as a bad trade-off. And whilst I don't want to re-ignite the debate over propulsion systems, take a look at the Surf Scooter that has been talked about recently http://www.devlinboat.com/dcsurfscoter25.htm
Where's the cockpit gone - it's full of engine! To avoid this you would need to raise the floor at least 1/2 a meter - suddenly it's a very different boat.

[Portager]

Be very careful with any LPG system. Research it thoroughly and make sure that the manufacturer recommends it for your intended use.

The Aqua Star models 38B and 125 are made by Bosch.

"The 38B is not approved for boat or RV installations." http://www.controlledenergy.com/pdf/38bman.pdf

"This product is not approved for manufactured homes (mobile home), recreational vehicles (RV) or boats." http://www.controlledenergy.com/pdf/125xman.pdf

The Aqua Star model 240FX is made by Takagi. The FAQ at http://www.houseneeds.com/shop/HeatingProducts/WaterHeating/t-k1/240fxfaq.asp states, "Can tankless water heaters be installed anywhere?
The Aqua Star 240FX (or any gas tankless water heater) cannot be installed inside of bathrooms or bedrooms or in mobile homes, recreational vehicles or boats. Closets are fine as long as adequate air supply is present."

Cheers;
Mike Schooley

[Willallison]

You're quite right Mike - a number of manufacturers specifically state that their units are not suitable for boats.
Here are a couple that are:
http://www.precisiontemp.com/ShowerMate.html I don't have a price on this unit yet - but it looks a little on the high side.

I've not checked back against the manufacturers yet, but these are marketed by a chandlery in the UK - reasonably inexpensive too:
http://secure.venus.co.uk/marineparts/waterheater.html

[Tim Bard]

Hi, I too am looking at diesel for power, cooking, heating nd water heating. Why carry more than one fuel? For power diesel engines and outboards are availble, for cooking, baking and cabin heating look at WALLAS from Finland. For water heating look at EBERSPACHER from Germany. It seems that the cooking heating thing is a "done deal". I am trying to figure out how to adapt the smallest EBER to provide hot water for the galley and shower on demand. I haven't had time to contact EBER on this yet but it seems this can be easily done. The only problem I haven't worked outhe detail on is how to simply store a volume of hot water without a real tank. One concept is to use oversized piping from the heater to the use points and a very small re-circulation pump back to the heater inlet, how best to control this is ???. The main pump from the sweet water tank can be a Flo-jet constant pressure VSD (no tank) pump for hot and cold.

All of this is for a modern Edwardian Gentlemens Launch for the Bays and Hawkesbury area of OZ.

Regards,

Tim

[Willallison]

Got a pic of the boat Tim?

[guest]

I actually did some serious research into propane hot water heaters some time ago. I had a manufacturer lined up, for prices that would put takagi to shame. I tried to do some market research and found that the market is not ready for this yet. A number of insurance policies will not cover a marine vessel with this type of item. So.. I dropped the idea. But, If anyone is interested in ordering a quantity of these things, post your contact info.

[Duane Mc]

Has anybody ever seen or read about a small electric heating device that attaches to a shower outlet and makes warm shower water?

I remember seeing one at a small resort washroom during a visit on the island Culebra about a decade ago -- it contained a small electric coil that somehow safely separated the water flow from a 120 volt current and produced very warm water.

Because there is no hot water holding tank and makes warm water on demand, it seems like such a device would be nice on a boat. Using an inverter to make 120 volts would be necessary though -- I wonder how many watts it draws?

Duane

[Willallison]

These devices are readily available - and mention has been made of them before for possible O-1 heaters - the problem is that the amount of energy required to run them would require either a massive (and heavy, expensive) battery bank or a generator. In bigger boats, the latter isn't a problem - then again, neither is space for a hot water cylinder. It also means that you lose any heating capacity that can be gained whilst underway - ie heat from the engine

[Duane Mc]

Thanks Will, I guess that would be a problem as to why these little electric heaters are not so popular on boats -- the power draw would really tax the battery banks.

However, since they would only operate for -- say, a three to five minute shower, perhaps some kind of capacitor storage device instead of a battery source would work. Capacitors -- unlike batteries, release lots of electrical energy quickly and are light weight devices. Still, there is that problem of making lots of electricity in the first place.

Duane

[SamAlec]

Helo, Duane. These devices are still very common in Brazil and they have an extra grounding wire, for prevention of electric hazards. They usually draw something around 5,000 watts (either 110 or 220 V). The problem is not only the high energy necessary to make them run, but worse than that, usually current inverters have only a bipole energy outlet, so grounding such a device is not effective.

[Duane Mc]

Thanks Sam -- you answered all my questions. It's a pity they draw so much energy -- the idea still sounds simple enough. Like I said, perhaps some kind of different electric storage device like a capacitor instead of a battery might give better performance if the coil material was modified to take less energy to heat the flowing water. Is there a website that sells them?

[Willallison]

If only it were that simple - the fact is that it takes a given amount of energy (about 1 calorie to raise 1 gram of water by 1 degree C between 0 & 100 C - interestingly it takes a further 540 calories to turn water at 100 into steam. Anyway, I digress....) What I'm trying to say is that to heat your water you can run your heater at 5 kW for 5 minutes or a 1kW heater for 25 minutes - the end result will be the same - hot water and flat batteries! But to heat flowing water quickly enough to produce 'hot' water, you simply can't get away from requiring lots of energy....
did that make sense... :confused:

[Duane Mc]

Yes -- it makes sense. I guess I'm just trying to suggest the idea that if a different type of battery/capacitor storage device -- together with a new designed resistor heater element for the shower head portal would make a better hot shower water maker for small boats than having to make and store hot water aboard in some water tank.

Thanks for the quick overview of how current technology works -- perhaps some future technique in either making or storing onboard electric power can make a quick add-on device to the shower head be the better choice in our heating needs.

Until then -- we live in the present...

[Portager]

We use capacitors in Laser systems, which require high power over a short duration, to store energy between pulses and level out the power draw. It works well for loads where the duration is in milliseconds, but when the duration approaches tenths of seconds the weight and cost trade tends to favor batteries. Unless you intend to take very short showers :D I think your best bet would be to use AGM batteries because they can provide very high discharge rates. Since the electric water heaters you are referring to are resistance heaters they should run on either AC or DC power so you could eliminate the power inverter, but to maintain full capacity you would want to provide the same voltage, i.e. 120 VDC. You could achieve that by using 12 small AGM batteries in series but then you need a 120 VDC charger or some complicated switching to charge the batteries in parallel i.e. 12 VDC and then discharge in series for showering. All in all it sounds like a very complicated and heavy system to get a hot shower.

I think O-1 would be a good application for solar water heating. If you mounted a solar water heater panel on the roof and a hot water tank in the bilge you could collect solar heat and store it until you need it. You can also get hot water storage tanks with a capsule of wax for better heat storage. When the wax melts it stores about 100 BTU per pound, so you can store more heat per unit weight and/or volume.

Regards;
Mike Schooley

[Duane Mc]

Thanks Mike -- you have provided some very interesting options for an onboard hot water heating system. The solar water option seems to be the easiest and most economical -- I like the wax capsule concept in keeping the water warmer longer.

Suffice to say, anybody trying to build a homemade device that uses electricity to heat a resistor for a hot water shower should be careful in designing it safely. Mixing water and electricity improperly can result in a jerky dance event for the bather -- and that's no fun.

Lately, I've been studying alternative electrical storage devices and I used to think some kind of light weight capacitor device could store as much -- if not more energy, than conventional electrochemical batteries, but after further review, the concept still needs more study. If I discover some new views on the matter, I'll post them here.

Again, thanks Mike!

[Portager]

The solar water option seems to be the easiest and most economical

Actually, the easiest and most economical solution is to use an inboard engine. However, if you insist on using an outboard, then I think the best option is solar.

Regards;
Mike Schooley

[FAST FRED]

The most common form of heating hot water is the small powered oil furnace.
This and a high cap insulated tank can provide winter heat or almost "endless " hot water.At some cost with great safty.

For USCG pax boats the Way Wolf is the classic.
For a yacht the Hurricane, works well as the circ pumps are sized to the vessel.

Toe kick heaters can be used dockside or underway , but good old baseboard heaters work far better , as no noisy thirsty blowers are needed for air circulation.


These units require very little DC in operation and are suitable for mooring living aboard in northern climes. Or in marinas with "Iffy" electric service, most marinas "after THE storm".

Our choice was for a dickinson Antartic with internal copper heating coil and thermosyphon to heat the vessel , light it in Oct and turn off in May, no maint!
And the heat stays on when the electric goes off for a few weeks.

HW is from a engine coil in water tank and 120V for dockside.Good insulation lasts a couple of days.

TAKE the daily showers while underway , to begin overnight with hottest water.

FAST FRED

[firestorm]

How much hot water do you need and at what temp? The hydraHot will provide a nearly endless supply of 120 degree water at about 1.5 gpm flow is fairly small 12 volt dc powered with 120v ac heating element for shore power also can be plumbed into a closed water cooling system to use engine heat to heat the boiler or runs a small deisel fired burner. Provides 3 zones of heat and hot water from 3 sources of power all of which I assume are allready on board your boat. The Aquahot is a slightly larger version which give a little more hot water and 5 zones of heating form a unit that is approx 18"x20"x36". I am not sure what it would take to make it usable on a boat but we use them all the time on luxury RV's only thing I can think of would be plumbing the exhaust and running the water lines to and from the unit it has it's own pumps and valves for the heating portion and has a tempering valve to control water temp which is adjustable. Do a search for Vehicle Systems Incorporated or for aquahot and you should find them.

[donjames]

I've stumbled on to the options thread and learned alittle more on what I have been researching.
I previously asked in another thead the pro's and con's of both electric and LP
comforts limited to heating, water,cooking, and perishable refrigeration.
any input from this thread would be helpfull.
I've attached a link to a water heating unit that has been designed for marine use and I surely like the LP format for all economic and efficiency
purpose for my boat project but still lack alot of first hand experience
on the safety and design for using LP in a marine environment.
Recently I have seen this unit or similar units in the home building industry
And since being in the trades for many years, for obvious reason I am comfortable with this type of system.
I just need to learn more about it for this application

Thank for any input
Donjames Bosch W125 waterheater http://www.go2marine.com

[FAST FRED]

The problem with propane is its heavier than air, so any malfunction could fill the bilge with explosive gasses.

Yachts sometimes get around this with an electric valve switch , by the stove with an indicator lamp.

There are "bilge sniffers" that will claim to turn off the gas , but do you want to bet your LIFE on its working?

And do you want the batt drain of about 1ah (24ah daily) just to hold the valve open?

RV's and houses have leaky floors (not airtight) that drain any leaking gas away ,hopefully boats don't.

IF you could mount everything outside in a self draining cockpit , no problem.

We chose propane and the switch & sensor for the galley range below, as the only batt drain is when actually cooking.
We also chose a huge RV fridge , outside in the self draining cockpit , A pain when getting breakfast goodies on a rainy day before sunrise.
But far cheaper than Marine refridgeration as it only used 20 lbs of propane in 25 days , and is quite handy for salsa & brew at the end of the day.

FAST FRED

[firestorm]

As a Master certified RV tech I can tell you there are some differences in the install of LP appliances in RV's but many of the princaples would also apply to boats first all LP appliances other than the cooktop are installed direct vented meaning the intake and combustion air must come from outside and they must be sealed from the interior of the coach. So we do not rely on leaky floors for gas safety the new generation LP cooktops have electronic igniction with thermicouple protection to prevent gas discharge when not lit. All appliances are at least double redundent in failure protection and it is allmost allways stupidity not componet failure which causes gas fires in a RV. Which could probably also be said of most boat fires. The LP detectors have a near zero failure rate and most of the ones sent in for warranty are in perfect working order we change them to give the customer peice of mind about the safety of their unit. We also try to educate them on how they work and what causes them to go off usually something they just did or cleaning solvent spills, Or hair spray which by the way usually contains propane as propellent. The PRE TELL LP detectors are combined with a LP shut off valve so when it detects a flamable vapor it shuts off the LP along with a audible alarm if I were going to use LP on a boat I would use this type of detector in my bildge area but I would wire it to a relay so that when it detected gas not only would it shut down the LP but it would turn on a blower to vent the bildge. I would also use alarms in the cooking and sleeping areas as a redundent protection. That being said the only thing I would consider using LP for on a boat would be for cooking and refridgeration and maybe for a nice big grill on deck. There are a large number of sizes and types of RV refridgerators that would work in a boat app properly installed and many offer 3 way power choose from 120vac 12vdc or LP. Since there are laws in the US about how much portable LP we can carry no more than 2 40lb bottles in most configurations using LP for heat or hot water would be to big of a pain in the butt to be usefull. For comfort heating and hot water I would look at the Aqua Hot Hydra Hot or the Hurricane deisel fired boiler systems as they are fairly effeicent and quite safe also all of them offer mutiple heat source ie 120vac electric heaters and also can be tied into your engine cooling system to draw engine heat to keep the boiler hot this would only work well on closed cooling systems but it is there .
Good Luck

[roamdeep]

The problem with propane is its heavier than air, so any malfunction could fill the bilge with explosive gasses.

Yachts sometimes get around this with an electric valve switch , by the stove with an indicator lamp.

There are "bilge sniffers" that will claim to turn off the gas , but do you want to bet your LIFE on its working?

And do you want the batt drain of about 1ah (24ah daily) just to hold the valve open?

RV's and houses have leaky floors (not airtight) that drain any leaking gas away ,hopefully boats don't.

IF you could mount everything outside in a self draining cockpit , no problem.

We chose propane and the switch & sensor for the galley range below, as the only batt drain is when actually cooking.
We also chose a huge RV fridge , outside in the self draining cockpit , A pain when getting breakfast goodies on a rainy day before sunrise.
But far cheaper than Marine refridgeration as it only used 20 lbs of propane in 25 days , and is quite handy for salsa & brew at the end of the day.

FAST FRED

roamdeep

yes propane is bad , but remember when gas was the same way the new solar powered vent fans with hoses to the bottom of the bilge and then another to the propane box will keep you safe , we have been doing this for a grate many years in the amazon river , you can build your box out of a platic bucket put the hose out the small hose and then the pour spout your vacum hose to the stern of your boat near the water away from your exaust port

allen

[dskira]

The wood stove is a good solution
Cheers
Daniel
http://www.marinestove.com/index.htm

[hoytedow]

Daniel,
The stove shown on web site you exhibited today looks excellent. I shall keep it in mind for a later time.

[WestVanHan]

Here's what I did.


Heat:
-need to run genset a little bit to recharge plate fridge,batteries,etc and had a heat exchanger to heat the water heater from it.Also heat from main engines.
Diesel hydronic for the main use.


Cooking:

Usually burning up a carcass of some sort,with veggies/potatos on the grill or burner.
Curries,stirfries,stews,etc are all cooked on the side burner.

-In summer,cooking heats up the cabin and smells it up as well,so I always cook up on the flybridge with side burner propane BBQ.
-In cold(er) weather,cooking inside heats it up BUT also water vapour condenses all over the glass.
Could use a ventilation fan,but then it sucks all warm air out.
Solution is to cook up on the flybridge.

Propane is fine with proper tank location and ventilation.

And get in the habit of turning it on and off at the tank each time you use it.

Use the galley stove to make beverages,other than that it's useless to me.
Gonna rip it out soon,going to a 2 element 120 volt to gain counter space.

[apex1]

The wood stove is a good solution
Cheers
Daniel
http://www.marinestove.com/index.htm

Beautiful old stuff, thanks Daniel!

And this is what I call a honest advertisement:
http://www.marinestove.com/redstovehug.jpg


no glitz, blitz, but a blond Top - Model that outperforms all professionals....

[boat fan]

Isn`t she just delightful !:)

[hoytedow]

Apex, I am always amazed at the eloquence of the imagery you bring to this forum.

[gonzo]

What's O1?

[TeddyDiver]

My best quess: Extraordinary ability... but not sure:confused:

[apex1]

And now Gonzo.
Must we die dumb?
What is O1?

edit:
Hahahaa..
now I have seen the old post from Portager one page back. Yes whats O-1?

Maybe a stove using only half of the oxygen available, leaving the other half for the crew?

[gonzo]

O-1 started the whole thread

[hoytedow]

Perhaps he means monoxide, as short for carbon monoxide?

[hoytedow]

Never mind. "Oh, I was mistaken."

[apex1]

Apex, I am always amazed at the eloquence of the imagery you bring to this forum.

Haha, nice words, thank you.
But this is something different. I notice a purrfect job, when others do´nt!

Can you imagine to remember the lascivious bitch from the ad two years ago, when you see a Chevy on the road?
Can you imagine YOU WILL remember this little treasure with her shy smile, when you see such a stove on a boat?

You might even remember the untidy background..........
..and the product makes you smile.

Sure proud Papa did not think this way round, neither most of the people looking at this picture.

But it is nothing less than a perfect ad, innocent and honest. For that reason we look at it again:
http://www.marinestove.com/redstovehug.jpg

Regards
Richard

[Willallison]

Oh Gentlemen...please... O-1 is short for Option One - the name given to the collaborative design project of which this thread is just a small part. And Gonzo - did you have a restless night - I'm surprised you can't remember... since I believe you participated in in it!