Integrated
On-Board Boat
Systems:
If you own or hire a narrowboat merely for your annual fortnight's cruising holiday, the boat's electrical and heating systems can be fairly straight forward. Summer cruising puts little strain on such systems - electric lights are only needed for a few evening hours per day in summer, and its warm anyway (well fairly) - most days you will possibly eat out at a canal side pub rather than stay on-board and watch TV. You will probably cruise for up to 8 or 10 hours per day.
If you own or hire a narrowboat merely for your annual fortnight's cruising holiday, the boat's electrical and heating systems can be fairly straight forward. Summer cruising puts little strain on such systems - electric lights are only needed for a few evening hours per day in summer, and its warm anyway (well fairly) - most days you will possibly eat out at a canal side pub rather than stay on-board and watch TV. You will probably cruise for up to 8 or 10 hours per day.
Contrast that to living aboard
all year round. Without the pressures of a time schedule, and with
winter 'stoppages', there will be days when you don't move the boat at
all. During the short winter days you may need the lights on from
3.30pm (rather than 9.30pm in the summer). For occasional spring and
autumn cruising, the cost of heating your boat may not be an issue -
long term winter heating costs are a different matter. Boat heating in
winter needs to be efficient (warm without excessive condensation) AND
be cost effective. A 'liveaboard' narrowboat's heating, electrical
& charging systems must be efficient, and preferably integrated
in use, for comfortable all year round cruising.
In short... a 'liveaboard' and
a 'holiday' Narrowboat are very differently equipped! Furthermore some
boat builders/brokers are not always the best judges of suitable
equipment for the
liveaboard lifestyle - many are merely used to hire/holiday
narrowboats. To be cynical, one could conclude that their
advice might be based on motives of fitout convenience and profit
rather than sound practical advice for those wanting to live aboard a
narrowboat, all year round. So if you are thinking
of buying a new narrowboat to live aboard? - Our consultancy service
could save you, literally, thousands of pounds.
12v CHARGING SYSTEMS - in
brief: On a narrowboat 12v power (for TV, water pumps,
lights etc) may be used for many hours, whilst the engine/alternator
charging system is lying idle - with the potential for flat batteries.
To overcome these problems, the following factors should be present
within a narrowboat's charging system:
- Separate battery banks should be installed for engine starting and general 'domestic' use. When installed correctly, this prevents the domestic usage from flattening the engine starter, or cranking, battery. Further separate battery bank(s) may be justified if an 240v inverter or, for those who can't manage without them, a bow thruster is envisaged.
- We must avoid the cranking battery from being drained by the other battery banks, whilst the engine is not running. It used to be the norm for a simple relay to do this job. When charging systems were fairly simple with low powered alternators, that may have been satisfactory - but not today. If a battery bank, for any reason fails, a modern alternator may attempt to charge the failed bank using high amperages - which may dangerously overload the relay. In our view the best option is a quality splitting diode system (although there are those who still like the old fashioned rotary switch).
- Each battery bank should have an appropriate amp/hour capacity to suit it's particular task and the lifestyle of the boat's occupants . For example, on 'Willow' with a relatively large engine and high domestic usage we have a 90amp/hr crank battery; 330amp/hr domestic battery bank; and 330amp/hr inverter battery bank;
- The alternator should be of a size, in charging capability, to suit the total amp/hr capacities of the battery banks it is being asked to charge. 'Willow' has a 90amp alternator which works efficiently enough - but we would prefer a 120amp version were we not constrained by the physical size of the unit and engine pulley/belt configurations.
- If your engine can be fitted with two alternators - all the better; BUT a suitably sized alternator with adequate battery bank amperage capacity will be of little use IF the alternator's regulator is designed merely for automotive use. For most of us an advanced alternator regulator (often called a battery management system) should be installed to override the automotive regulator and thus obtain best advantage of the alternators rated output. At the same time these advanced units have built in provision to protect batteries from over charging. If there are to be warranty issues with fitting such a system to standard alternators, newer technology is now available to achieve the same result whilst avoiding the warranty problems.
SPACE HEATING SYSTEMS:
Diesel & Gas Central Heating: Boat fitters often specify diesel forced air (or even gas) central heating systems for new boats. These gas and diesel central heating systems can be very convenient and take up little space - and from the boat fitter's point of view are easy to fit with the bonus of a reasonable profit margin.
From the boater's point of view, the diesel versions can have noisy exhausts (at night in a line of moored boats!!!) and spares for such diesel systems can be very expensive. Recently there has been a concern as to whether the red diesel now available has a sufficiently high cetane rating to suit these systems. At the time of writing this piece, diesel prices are climbing steadily. The initial outlay of fitting such a diesel central heating system can cost an arm and a leg (of course high cost items can have high profit margins - and if we were cynics we might suspect that's why some boat builders like to fit them). You would be forgiven if you sensed that we don't particularly rate diesel central heating systems for narrowboat heating in winter.
We do, however, like the gas central heating systems if used as a backup to a solid fuel system, and to provide a quick supply of hot water in summer (or warmth if its not quite cold enough for a proper fire).
Solid Fuel Fires: Contrast all of that above with a relatively cheap solid fuel fire. They come in a variety of styles, some with a back boiler to heat radiators or the domestic hot water (although their strength is with their space heating, rather than as water heating systems). They provide a cheery winter glow with various types of coal bought anywhere round the canal system (or use free wood from fallen trees).
Condensation: A solid fuel fire draws in the cooler, water vapour laden, air at the bottom to fuel the burning process. The water content drawn in, or produced in burning, is then expelled from the fire box interior, up the chimney - providing a warm AND dry boat. It isn't a matter of whether or not water vapour is produced - The real issue is whether or not the system gets rid of the water vapour that IS produced. A boiler located under the back deck is going to do little to expel water vapour (condensation) found in the saloon or galley, whereas solid fuel fires (and drip-fed diesel systems) located in the saloon DO get rid of that condensation.
Positioning of the fire can also be important - for the boat fitter it is very convenient to put the fire right beside the front door - but heat rises straight out of the boat's front door every time its opened. Fitouts with the fire positioned further back within the interior of the boat will make much better use of the heat.
Secondary Heating: Sometimes the old tried and tested solutions work better than some modern alternatives. However, there are drawbacks to having only a solid fuel fire. There are autumnal evenings when its chilly enough to need heating, just to bring the temperature up a bit then, when we light a fire, an hour later everyone is needing to strip off - and the fire won't go out until 9pm the next day. So a secondary system which can be turned on and off, at will, is very useful - or you could just burn wood on your fire (which will go out quicker if left alone).
For Domestic water heating, a calorifier can be put to good use (looks like a domestic hot water tank - but designed to withstand the higher water pressure found on a boat). A Calorifier is actually an efficient heat exchanger. The main part of the calorifier tank contains the water to be heated, supplied from the boat's cold freshwater supply. Hot water from, primarily, the boat engine cooling system then passes through copper piping which, in the form of a coil, passes through the cold freshwater within the calorifier tank. Heat passes from the hot engine coolant within the coil, through the metal of the copper pipe coil, and heats the main body of cold fresh water within the calorifier tank. That heated freshwater is then drawn on by the boat's hot water taps, as and when required. So, whilst cruising, we have hot tap water for free - has be good. Additional coils are usually present to allow additional sources of hot water to do the same job (eg. hot water from sources such as the gas/diesel central heating boiler or even from the back boiler of a solid fuel fire).
Integrated Systems? Even when not cruising, we merely run the engine for an hour early in the day - batteries charge and domestic water heats up; Repeat the process in the evening before tea time - job done. This is an example of the integrated system we mentioned earlier - more of these consultancy aspects on our courses.
Diesel & Gas Central Heating: Boat fitters often specify diesel forced air (or even gas) central heating systems for new boats. These gas and diesel central heating systems can be very convenient and take up little space - and from the boat fitter's point of view are easy to fit with the bonus of a reasonable profit margin.
From the boater's point of view, the diesel versions can have noisy exhausts (at night in a line of moored boats!!!) and spares for such diesel systems can be very expensive. Recently there has been a concern as to whether the red diesel now available has a sufficiently high cetane rating to suit these systems. At the time of writing this piece, diesel prices are climbing steadily. The initial outlay of fitting such a diesel central heating system can cost an arm and a leg (of course high cost items can have high profit margins - and if we were cynics we might suspect that's why some boat builders like to fit them). You would be forgiven if you sensed that we don't particularly rate diesel central heating systems for narrowboat heating in winter.
We do, however, like the gas central heating systems if used as a backup to a solid fuel system, and to provide a quick supply of hot water in summer (or warmth if its not quite cold enough for a proper fire).
Solid Fuel Fires: Contrast all of that above with a relatively cheap solid fuel fire. They come in a variety of styles, some with a back boiler to heat radiators or the domestic hot water (although their strength is with their space heating, rather than as water heating systems). They provide a cheery winter glow with various types of coal bought anywhere round the canal system (or use free wood from fallen trees).
Condensation: A solid fuel fire draws in the cooler, water vapour laden, air at the bottom to fuel the burning process. The water content drawn in, or produced in burning, is then expelled from the fire box interior, up the chimney - providing a warm AND dry boat. It isn't a matter of whether or not water vapour is produced - The real issue is whether or not the system gets rid of the water vapour that IS produced. A boiler located under the back deck is going to do little to expel water vapour (condensation) found in the saloon or galley, whereas solid fuel fires (and drip-fed diesel systems) located in the saloon DO get rid of that condensation.
Positioning of the fire can also be important - for the boat fitter it is very convenient to put the fire right beside the front door - but heat rises straight out of the boat's front door every time its opened. Fitouts with the fire positioned further back within the interior of the boat will make much better use of the heat.
Secondary Heating: Sometimes the old tried and tested solutions work better than some modern alternatives. However, there are drawbacks to having only a solid fuel fire. There are autumnal evenings when its chilly enough to need heating, just to bring the temperature up a bit then, when we light a fire, an hour later everyone is needing to strip off - and the fire won't go out until 9pm the next day. So a secondary system which can be turned on and off, at will, is very useful - or you could just burn wood on your fire (which will go out quicker if left alone).
For Domestic water heating, a calorifier can be put to good use (looks like a domestic hot water tank - but designed to withstand the higher water pressure found on a boat). A Calorifier is actually an efficient heat exchanger. The main part of the calorifier tank contains the water to be heated, supplied from the boat's cold freshwater supply. Hot water from, primarily, the boat engine cooling system then passes through copper piping which, in the form of a coil, passes through the cold freshwater within the calorifier tank. Heat passes from the hot engine coolant within the coil, through the metal of the copper pipe coil, and heats the main body of cold fresh water within the calorifier tank. That heated freshwater is then drawn on by the boat's hot water taps, as and when required. So, whilst cruising, we have hot tap water for free - has be good. Additional coils are usually present to allow additional sources of hot water to do the same job (eg. hot water from sources such as the gas/diesel central heating boiler or even from the back boiler of a solid fuel fire).
Integrated Systems? Even when not cruising, we merely run the engine for an hour early in the day - batteries charge and domestic water heats up; Repeat the process in the evening before tea time - job done. This is an example of the integrated system we mentioned earlier - more of these consultancy aspects on our courses.
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