hot water from the engine for radiators

[Robbo]

I would use large pipes to cause less resistance for the water if you have long runs of pipe. It's not an issue of the pump having to work harder as it will be the centrifugal type, but it will improve the flow to the radiators.

[Biggles]

Biggles, although engine failure is not usually critical in inland waterways, a good system will be one that doesn't impact on engine reliability. So the question is, does having the engine coolant circulating through pipework, fittings and radiatiors pose more risk to loss of engine coolant that having it flowing through the relatively short distance to a plate exchanger. But then what risk does the plate exchanger itself present? Thin plates brazed together, probably not very resistant to vibration.

 

I don't know, and also have done as you are suggesting, just not sure its the best solution if the system can be made to work without an exchanger. I suppose we don't know the long term reliability of the plate exchangers in a boaty engine environment.

 

 

I'm not saying the engine to radiator direct route is wrong, indeed it seems some have this method working just fine, its my opinion that the way I did it is a better way. Each system is separate. I haven't suggested this could cause engine problems or failure, other posts have mentioned engines

[ditchcrawler]

I'm inclined to agree, but Dean asked about implementing his idea, not whether it was a practical one! As you say, it will take longer for the engine to heat up, and this will not be very good for the engine (running cool for a long time) - although that effect depends on how big the radiators are.

 

A better solution would be a back boiler on the stove to run the rads at the back.

Also remember the rads and pipe work wil;l be at the same pressure as the engine cooling, see header tank cap for your engine.

[DeanS]

I like the heat exchanger method...it's not that expensive to use one.....and I dont fancy using the engine water pump for things it wasnt primarily designed for. I'd rather have a seperate pump for rads...just makes more sense in my book.

 

I doubt I'll have time or funds to install a full rad system for this winter....but....if needs be...I may have to:) In the long run, I'm preparing for surviving through winter CC-ing....so it's got to be done

 

Like someone mentioned...free heat being wasted...when cruising in winter months.

[adrianh]

I run 5 radiators directly off my Kubota(Beta) engine using this method. The standard engine pump is more than adequate.The circuit uses a 22mm copper ring main with the radiators tapped off in the old fashion single pipe heating circuit format.

I have 2 manual selector valves to allow either the engine or the Mikuni ( with its own pump)to heat the boat. All return pipes are commoned allowing me to use 1 reasonable size expansion bottle with pressure relief cap for the whole system.

The system runs with the normal level of antifreeze.

Take care using plastic pipe runs as they must take the maximum engine temperatures - 80 deg C ?- I would use only the Hepco grey range.

I used good quality 5/8 bore vehicle type heater hose for flexible connections, with the correct brass hose tails and stainless jubilee clips. Use plastic spiral wrap on the outside to avoid abrasion damage if this touches anything.

I bought a lot of my parts from ASAP supplies or my local chanderly ( ABC)

[nicknorman]

I like the heat exchanger method...it's not that expensive to use one.....and I dont fancy using the engine water pump for things it wasnt primarily designed for. I'd rather have a seperate pump for rads...just makes more sense in my book.

 

I doubt I'll have time or funds to install a full rad system for this winter....but....if needs be...I may have to:) In the long run, I'm preparing for surviving through winter CC-ing....so it's got to be done

 

Like someone mentioned...free heat being wasted...when cruising in winter months.

One advantage of the exchanger route, is that (as I think someone mentioned before) you can add other sources of heat later, such as the back boiler that I really think you should get! If you did that without the exchanger, you would end up pumping your precious heat into the engine, in a probably uninsulated part of the boat.

[nb Innisfree]

As regards engine water pump, ours supplies a circuit each side of boat, one nearly 40' the other 35'. There is enough resistance to allow a quick engine warm up in summer but allows cals to get hot about an hour later, doesn't put any extra load on pump.

 

System runs unpressurized but we can isolate engine to run pressurized with its original header tank and enable ch circuit to be worked on.

[smileypete]

FOOD FOR THOUGHT.

THANKS EVERYONE

 

The thought of having to start the engine every day fills me with dread (which is why in summer we have solar panels for batt charging etc).

The coal fire really manages to heat the front of the boat, so I'm tempted to try a bunch of 12v computer fans and circulate the heat slowly , but consistantly to all rooms. The trick however, is to blow the ceiling air downwards into each room....so it's not just circulating at head height. This wouldnt be the greatest solution, but is fairly cheap and might just take the edge off (this winter). Last winter we had the coal fire on for 5 months solid....

 

Some of those 12V fans make a real racket though....I might have to buy proper ones.

 

Try running the 12V fans on a lower voltage, say 5V to 9V, or use a bigger slower running fan:

 

http://www.ebay.co.uk/itm/New-Round-Transparent-DC-12V-22CM-220MM-Cooling-Cooler-Fan-/310672981882?pt=UK_Computing_Case_Fans

 

For heating from the engine you could try a car heater matrix plus some fans to get more-or-less what catweazle has. Engine overcooling can be avoided just buy putting a the fans on a pipe themostat.

 

Plate exhangers are really handy for heating the cauliflower from the engine when there's no spare coil left, posted a diagram a while back that someone built and seems to be happy with:

 

http://www.canalworld.net/forums/index.php?showtopic=55788&p=1058793

 

cheers, Pete.

~smpt~

Edited September 7, 2013 by smileypete