Boat Central Heating

[funinthesun]

Hello all,

can anyone tell me any reason i can't fit standard central heating radiators to my motor boat to be run off either the loop for the hot water cylinder or a new loop from the other engine? Would this be cost effective/possible?

 

[Talbot]

Been done using a mini car heater matrix and computer fans.

Normal house radiator too much water, not enough radiating fins.

 

[Cariadco]

You might encounter problems with the engine's Water Pump unable to shift the water to all the radiators, maybe giving you hot spots in the engine where the flow rate is slow.

I fitted a pair of Oil type 2KW electrical heaters whilst we lived on the boat, last winter. Ok, it was in Corfu and not nearly as cold as the UK, but trust me, it did get very cold overnight!! but the cabin and bedrooms we're very warm and snug.
Oh, bye the way, the eleci on the marina's free.

 

[sarabande]

at a guess, each radiator will be using around 1.5 kW, so if your domestic hot water / calorifier can cope with that level of output (times the number of rads, of course !) it should be possible.

Problem though if you have 3 or 4 rads, as there's not enough in a standard calorifier to service the rads sufficiently.

 

[Marsupial]

Several things to consider, and then you must take a view on if it’s worth it.

1. Your calorifier is fed with pipe; pipe is able to withstand much higher pressures than conventional radiators. You would have to find a source of “tubular” radiators, Look at kick-space heaters they would be ideal IMHO.
2. You need to determine how much heat you have available from the engine(s). Just guessing but you will need about 5KW to heat a 30-35ft power boat, possibly more if you are in a cold location. You don’t give the size of your craft but providing more heat in the living quarters is better than not enough (you can turn a large heater down, you cannot turn a small one up!) so a proper heat loss calculation is urgently required.
3. The bad news: With the additional “cooling load” on the engines they will take longer to heat up and will therefore wear out quicker. Any coolant leaks on the heating system would threaten the reliability of the main engines. On reflection I would buy a webasto or two.

 

[FlorealIII]

I've seen a boat who used two old car radiators and it worked .
Probably there is a limit on the number of radiators you can use .

 

[Saddletramp]

Can you make your own with copper pipe? At least you can experiment with it and put it where you want.

 

[PeterGibbs]

This is good advice. After you've considered the sheer weight and inconvenince of siting the rads, you might reconsider the whole project.

A hot air heater - or even a Mikuni gas system would be superior, flexible and lighter/mnore reliable.

Soon the cost of running the engine even a short while extra for heating or charging purposes is going to become very expensive (even allowing for self declared lower duty fuel!)

PWG

 

[charles_reed]

The best boat central heating

I ever experienced was a hot water system fitted on a Swedish boat.

The boiler was a standard Eberspacher and the minute heat exchangers each had a separate thermostat and fan motor (also by Eberspacher).

In comparison with the hot-air lorry heaters that most boats are fitted with it was incomparably more effective (it also supplied hot water).

The idea you propose has one major disadvantage - you'll have to run the engine to warm the boat, minor disadvantages would be weight, obtrusiveness, cost of fuel and (possibly) increased engine wear.

I threw away the Eberspacher with which my boat came fitted and, because you're usually in a marina with shorepower when you need heat, replaced it with electric fan-heaters - far more effective and economical and good for external temperatures of down to -8C.
If I need heating when not berthed I use the LPG oven - crude but effective, as it acts as a heat sink.

 

[nedmin]

I have normal domestic type radiators, fitted by the maker, on my steel boat.They are the modern high efficiency type so dont hold so much water.You can get them to quite compact sizes, The system works v. good and much better than the hot air on my previous boat as I found you were either too hot or too cold. The Webasto also delivers hot water when needed.

 

[macnorton]

I did it with three house radiators, direct from the engine cooling system (120 hp 6cyl ford) worked a treat and kept the water hot.
On another boat I used a car heater rad with a fan, that worked well too.

 

[wotayottie]

[ QUOTE ]
Several things to consider, and then you must take a view on if it’s worth it.

1. Your calorifier is fed with pipe; pipe is able to withstand much higher pressures than conventional radiators. You would have to find a source of “tubular” radiators, Look at kick-space heaters they would be ideal IMHO.


[/ QUOTE ]

Is this right? On modern non vented central heating systems I seem to remember (mine is vented so I'm not 1100% sure) that the pressure goes up to 2 or 3 bar = 45 psi. The highest pressure pressure cap I have seen for an engine cooling system is 15 psi

 

[ADLS]

I tried a reclaimed car heater rad and fan but the engine water pump could not handle the long pipe run, engine water pumps agitate the water they don't pump under pressure.

My domestic hot water is heated by the starboard engine with the clorifier tank sited 500mm away so no problem with flow, the water reaches 80deg after about 30min running time and the engines thermostats prevent long cold running.

I plan to try out some matrix rads and inline pump to see how well the clorifier heats them, if the system works well I'll buy another tank and run the heating system off the port engine.
Though this system will give heat during a passage and for a short while afterwards, I don't think it would be cost effective to run a 2.5lt engine for cabin heating while moored or at anchor. So I won't be chucking the small fan heater for use in harbour and the thought of splashing out on an inboard genny gets more appealing every cold morning.