Propane, the kiss of death

[Finalee]

A knife is dangerous too if not stored properly. Often times these are preventable with
a proper maintenance program.

[noelex 77]

Originally Posted by Pelagic

Hats off Dockhead.....

Originally Posted by Pelagic

You are a powerful debater....

Originally Posted by Pelagic

......who happens to be correct !

Well maybe .


The question whether electric cooking or propane is safer is an interesting one to ponder.

Overall I would agree with most that electric cooking probably has safety advantages, but I think these advantages are small at best.

If you inspect many older cruising boats their propane system is often terrible. Old equipment, worn hoses, and the lack of modern mandatory safety equipment such as remote shut off valves etc. It is not even unusual to see spare bottles stored in non vented lockers. Despite these shortcomings, accidents are rare. This suggests the dangers are very small especially with a little care and maintenance.

While all electric cooking removes any propane hazard completely it generally introduces other new electrical hazards. Electric cooking demands large amounts of electrical power and this in turn requires large inverters, large alternators, large solar arrays, generators, battery chargers, shore power conections and often lithium batteries. While in many cases this equipment may have been fitted anyway, electric cooking requires these devices to be on the limit of what is technically feasible.

I do wonder about the long term reliability and safety of 5000w inverters and 360A alternators especially on a 12v system. Everything has to be very well engineered and maintained in pristine conditions for the sustained currents of the magnitude required.

I think we will have to wait some years to find out. Will a 10 year old boat with the equipment required to power electric cooking be more or less safe than a similar age propane system? We know propane systems of this age are reasonably safe even when abused (as unfortunately crusing sailors tend to do) will electric cooking systems be safer? Time will tell.

[Thumbs Up]

Those articles describing NOx emissions from gas cooking don't link to any data nor do they specifically mention propane (propane burns with different chemistry than natural gas or butane). A gas appliance must have a properly jetted and adjusted flame to burn at maximum efficiency with minimum noxious fumes. Most boats with electric galleys use diesel generators for power. Some fumes from this power generation invariably will end up inside the cabin and breathed by it's occupants. By far, most cruising boats would need major upgrades to install electric galleys. A properly maintained boat has many deadly deadly systems that are only mitigated by carefully engineered installations, constant vigilance, and maintenance. Combustible gas alarms and remote shutoff valves are easy enough to obtain and install. You don't see too many actual fire suppression systems in yachts. Aside from propane there are many other ways that boats catch fire. Most chefs prefer a gas flame. When not used for baking a small cylinder of propane can last for months or more, and refills are readily available almost anywhere. Natural gas would be inherently safer on a boat because it is lighter than air so will never accumulate in the bilge but can not be easily liquefied. I suppose someone could devise a methane generator on a boat using sewage or compost as the source.

[jimbunyard]

Originally Posted by Finalee

A knife is dangerous too if not stored properly. Often times these are preventable with
a proper maintenance program.

Perhaps even more succinctly, 'Life, the kiss of death...'

[Dockhead]

Originally Posted by noelex 77

. . .
Well maybe .

The question whether electric cooking or propane is safer is an interesting one to ponder.

Overall I would agree with most that electric cooking probably has safety advantages, but I think these advantages are small at best.

If you inspect many older cruising boats their propane system is often terrible. Old equipment, worn hoses, and the lack of modern mandatory safety equipment such as remote shut off valves etc. It is not even unusual to see spare bottles stored in non vented lockers. Despite these shortcomings, accidents are rare. This suggests the dangers are very small especially with a little care and maintenance.

While all electric cooking removes any propane hazard completely it generally introduces other new electrical hazards. Electric cooking demands large amounts of electrical power and this in turn requires large inverters, large alternators, large solar arrays, generators, battery chargers, shore power conections and often lithium batteries. While in many cases this equipment may have been fitted anyway, electric cooking requires these devices to be on the limit of what is technically feasible.

I do wonder about the long term reliability and safety of 5000w inverters and 360A alternators especially on a 12v system. Everything has to be very well engineered and maintained in pristine conditions for the sustained currents of the magnitude required.

I think we will have to wait some years to find out. Will a 10 year old boat with the equipment required to power electric cooking be more or less safe than a similar age propane system? We know propane systems of this age are reasonably safe even when abused (as unfortunately crusing sailors tend to do) will electric cooking systems be safer? Time will tell.

I think you make some very good points here.


Just one quibble -- you say: "While in many cases this equipment may have been fitted anyway, electric cooking requires these devices to be on the limit of what is technically feasible."


I think this is not the case. In my experience, boats are either spartan and low power, or they are not. Once you have the capacity to run electrical devices of say 2000 watts, then you already have a bunch of these on board -- electric kettle, microwave, vacuum cleaner, and the biggie -- electric heaters. So 2000 watts of induction cooking just doesn't change anything in that context; even 3000 watts. Certainly converting to electric cooking would add zero risk in the case of my own boat -- I even have a washer and dryer, for goodness sake. Very many cruisers use electric heating at the dock -- this is far more demanding then electric cooking on the safety of the electrical systems. I run 3000 watts of electric heating for days at a time; whereas induction cooking might use full power for at most minutes at a time.



But nevertheless your point about the long term safety of the "high powered boat" is well taken. I think we've already arrived at the era of the high powered boat even before electric cooking, and not actually all that long ago -- my previous boat was distinctly low power.



So it will be interesting to see how these boats age. My boat is now 20 years old and still doing fine, but I think I will increase the frequency of my IR gun checks on high powered electrical connections.



And I agree that 12 volts makes the high powered boat more dangerous. I'm 24v and would probably do 48v if building from scratch or doing a complete rewire.


A small detail -- AC sockets are a fairly frequent cause of fires. I guess these and shore power inlets must be the most common cause of electrical fires. In this regard 230v and the BS 1363 plugs and sockets simply rule.

[Pelagic]

Originally Posted by Dockhead

I think you make some very good points here.


Just one quibble -- you say: "While in many cases this equipment may have been fitted anyway, electric cooking requires these devices to be on the limit of what is technically feasible."


I think this is not the case. In my experience, boats are either spartan and low power, or they are not. Once you have the capacity to run electrical devices of say 2000 watts, then you already have a bunch of these on board -- electric kettle, microwave, vacuum cleaner, and the biggie -- electric heaters. So 2000 watts of induction cooking just doesn't change anything in that context; even 3000 watts. Certainly converting to electric cooking would add zero risk in the case of my own boat -- I even have a washer and dryer, for goodness sake. Very many cruisers use electric heating at the dock -- this is far more demanding then electric cooking on the safety of the electrical systems. I run 3000 watts of electric heating for days at a time; whereas induction cooking might use full power for at most minutes at a time.



But nevertheless your point about the long term safety of the "high powered boat" is well taken. I think we've already arrived at the era of the high powered boat even before electric cooking, and not actually all that long ago -- my previous boat was distinctly low power.



So it will be interesting to see how these boats age. My boat is now 20 years old and still doing fine, but I think I will increase the frequency of my IR gun checks on high powered electrical connections.



And I agree that 12 volts makes the high powered boat more dangerous. I'm 24v and would probably do 48v if building from scratch or doing a complete rewire.


A small detail -- AC sockets are a fairly frequent cause of fires. I guess these and shore power inlets must be the most common cause of electrical fires. In this regard 230v and the BS 1363 plugs and sockets simply rule.

I agree, boats fitted with example,... a 10kw Generator already have wiring/Breakers sized to 230v-30a capacity or even 50a

If they also carry a 5000w Multi, then it gives them a lot of flexibility to manage their stored energy during cooking times.

[Dockhead]

Originally Posted by Pelagic

I agree, boats fitted with example,... a 10kw Generator already have wiring/Breakers sized to 230v-30a capacity or even 50a

If they also carry a 5000w Multi, then it gives them a lot of flexibility to manage their stored energy during cooking times.

Indeed. My boat was built from the ground up as a "high power boat", with 100 amp (*24v) school bus alternator, heavy duty 6.5kW diesel generator, 50 amp main panel and transfer switches, 32 amp shore power system. Electric cooking would certainly not " stress these systems to their technical limits"

And I think this is pretty typical for larger cruising boats these days, and even medium ones. Anyone with air conditioning on board, or who uses electric heat on board in the winter, is already handling far more power than is required for electric cooking.

[rslifkin]

Originally Posted by Dockhead

Indeed. My boat was built from the ground up as a "high power boat", with 100 amp (*24v) school bus alternator, heavy duty 6.5kW diesel generator, 50 amp main panel and transfer switches, 32 amp shore power system. Electric cooking would certainly not " stress these systems to their technical limits"

And I think this is pretty typical for larger cruising boats these days, and even medium ones. Anyone with air conditioning on board, or who uses electric heat on board in the winter, is already handling far more power than is required for electric cooking.

Agreed. My boat was built as high powered on the 120v side, but fairly simple on the 12v DC side (which has been changed since). But my boat is 35 years old, so huge alternators weren't common, inverters were rare, etc. So it's just the 2x 50A at 120V shore power and the 6.5kw genset that provided all of the big power originally.

[Dockhead]

Originally Posted by rslifkin

Agreed. My boat was built as high powered on the 120v side, but fairly simple on the 12v DC side (which has been changed since). But my boat is 35 years old, so huge alternators weren't common, inverters were rare, etc. So it's just the 2x 50A at 120V shore power and the 6.5kw genset that provided all of the big power originally.

Sure, and if you were to go to electric cooking, I bet you would just power it from the generator. And you probably wouldn't do it at all since you wouldn't want to run the generator every time.


I don't think many people are going to switch to electric cooking, if their boats are not already set up to deliver the kind of power they need. Just don't see how it could be worth it.


Even I -- as a big fan of induction cooking and big hater of gas -- stick with gas on this boat because it's too much hassle to convert, even with no problems supplying the power.


Well, but for the countertop induction plate.

[Chotu]

These are some good arguments for the safety of electric (specifically induction) cooking.


It’s important to remember, but easy to forget, that we are talking about 3kw AC power. I use more than that all day long with my air conditioning and that comes from the generator. It’s not a big safety hazard until you are running an inverter to get DC power to supply 3KW. Then, you need to be sure that DC system is staying cool, corrosion free and even a little over spec for safety.

So yeah, I don’t see an incremental increase in danger using electric cooking of any type. Unless you make a mistake running the microwave, windlass and cooktop at the same time off the batteries. Definitely some power management needed. Even then, you should be protected by breakers or fuses on the DC side.

Only thing that freaks me out is not being able to cook if you have a failed inverter or generator or electrical something or other.

Questions:

How much total power is used a day by an induction cooktop assuming worst case of boiling water for breakfast, lunch and dinner?

I chose a different sort of electrical system what relies more heavily on solar than on battery capacity. So, I have a small battery bank (to save weight) but 1500 watts solar to provide power, plus 5kw of generator power. The theory is, I am awake during the day when power is available and I’m asleep at night when just the refrigeration needs battery power. So a large bank isn’t necessary.

Anyway, I’m wondering about some worst case induction numbers to see if I can swing it.

Considering coming around to the dark side, but curious about the power demands.

[Dockhead]

Originally Posted by Chotu

These are some good arguments for the safety of electric (specifically induction) cooking.

It’s important to remember, but easy to forget, that we are talking about 3kw AC power. I use more than that all day long with my air conditioning and that comes from the generator. It’s not a big safety hazard until you are running an inverter to get DC power to supply 3KW. Then, you need to be sure that DC system is staying cool, corrosion free and even a little over spec for safety.

So yeah, I don’t see an incremental increase in danger using electric cooking of any type. Unless you make a mistake running the microwave, windlass and cooktop at the same time off the batteries. Definitely some power management needed. Even then, you should be protected by breakers or fuses on the DC side.

Questions:

How much total power is used a day by an induction cooktop assuming worst case of boiling water for breakfast, lunch and dinner?

I chose a different sort of electrical system what relies more heavily on solar than on battery capacity. So, I have a small battery bank (to save weight) but 1500 watts solar to provide power, plus 5kw of generator power. The theory is, I am awake during the day when power is available and I’m asleep at night when just the refrigeration needs battery power. So a large bank isn’t necessary.

Anyway, I’m wondering about some worst case induction numbers to see if I can swing it.

Considering coming around to the dark side.

Someone using induction in practical daily life should put in a Kill O Watt or similar and do actual measurements.

I can only tell you approximately.

Induction cooking uses far less power than air conditioning. Full power of 2000 watts (about 9 amps of 230v power) is used only briefly unless you are heating up a big pot of water for pasta of something, and even then it's just a few minutes. Once temp is reached, the hob throttles down and uses much less power, typically a couple hundred watts say frying something.

I have a 440AH * 24v battery bank, and cooking a whole meal on induction via the inverter off batteries consumes less than 10% of capacity for sure, maybe less than 5%. I don't typically run it off batteries as anyway it's always been my habit to run the generator when I'm cooking dinner, and at the same time wash clothes, heat water, whatever other power intensive jobs there are. But running it off even a fairly modest battery bank as mine is definitely realistic.

I would think you would have no problem. But you can easily test it by buying an inexpensive countertop induction hob like a NuWave (what I have) and trying it out. Costs only $100 in the first place, and if you don't like it you can just take it off and use it at home. So nothing to lose.


This way you also have gas ready in case your batteries are down and you don't feel like starting up the genset.

[rslifkin]

Originally Posted by Dockhead

Sure, and if you were to go to electric cooking, I bet you would just power it from the generator. And you probably wouldn't do it at all since you wouldn't want to run the generator every time.


I don't think many people are going to switch to electric cooking, if their boats are not already set up to deliver the kind of power they need. Just don't see how it could be worth it.


Even I -- as a big fan of induction cooking and big hater of gas -- stick with gas on this boat because it's too much hassle to convert, even with no problems supplying the power.


Well, but for the countertop induction plate.

In my case, the boat was actually built with an all electric galley (even in the mid 80s). They figured the generator was sufficient. And based on the original battery configuration, they figured the generator was going to see a lot of use when away from the dock anyway.

I've since added a 2kva inverter and a proper house bank, so that covers the coffee maker, toaster, etc. I haven't put the microwave circuit on the inverter, but I may at some point. The stove (resistive electric) is generator or shore power only, but that's no big deal.

When we're away from shore power, we'll need a generator run to make hot water for showers at some point anyway, so we typically just pair that up with cooking dinner. That usually comes out to 40 - 60 minutes of generator runtime once a day.

[geoleo]

Originally Posted by Chotu

My head hurts.

So why didn’t they store the propane in the propane locker, where these things can’t happen?

Boat poker: I’ve perused your site over the years and seen some interesting stuff, but this might be the most terrifying set of pics you’ve ever shared.

My 1990 Beneteau 41S5 came with a propane locker that had a hose drain at the bottom that turned into a P -trap that closed off any chance of leaking propane getting out of the hull!!! Fixing that .

[Dockhead]

Originally Posted by geoleo

My 1990 Beneteau 41S5 came with a propane locker that had a hose drain at the bottom that turned into a P -trap that closed off any chance of leaking propane getting out of the hull!!! Fixing that .

Don't feel bad. My boat, otherwise so beautifuly and thoughtfully built, had a hose drain to the gas locker with a negative slope in one part of it! Also defeating the whole purpose of the drain!


I fixed that by shortening and rearranging the hose. I suggest everyone who has a gas locker drained with a hose should check that.

[valhalla360]

Originally Posted by Pelagic

Again, I would argue that an explosion is inherently more dangerous than a fire, whatever the cause.

You have to define what an explosion is first...

I've seen a few propane explosions...usually they are more scary than dangerous. A quick poof of flame pops that doesn't have time to start a fire...of course this is when it's not confined.

Fires, particularly electrical fires often start hidden behind panels. By the time you are aware, they may be beyond controlling.