Automotive radiator for marine heating??

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swanny

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Hi, I want to boost the output from my Eber water heating system and am considering putting a radiator in the aft cabin and heads. However, finding suitable rads which are small, give good heat output and are not sooo expensive is a problem. Would it be possible to make some up using car cooling radiators? I figure they are designed to disipate heat quickly and efficiently albeit with wind blasting through them. Would they still give out a lot of heat without the wind/fan element? Dressed up or over they could be made to look nice/nautical. Any views? Ta.
 
Use the heater matrix instead, available from all good local car breakers. Much smaller than a rad, and designed for the job.
I also have a small domestic double rad in the heads - all plumbed in with plastic plumbing fittings (nb it was a professional installation by a previous owner). I am very pleased with the set-up
 
You might consider covered finned radiator tubes - do a Google search for finrad. Easy to plumb in, relatively discreet.
 
I am just about to install a webasto with car/van heater matrixes (SP?). with a few PC cooling fans thrown in you can make a blown heater for under £25. At that sort of price I figured I can put one or two in every cabin, each with an individual switch, means that heat can be where you want it.
 
I set up a test in my garage with a D5W and 2 heaters from old minis. It worked fine though I never fitted to boat as I couldnt figure how to tap into the water system.
I thought that the heater fans could be noisy as they only had one setting also consider the power requirements. Some way to bypass all the plumbing in case of leaks would be useful.
Regards peter
 
As above, I was also going to suggest a mini heater, or perhaps the after market land rover heater that was used in the series land rovers. Think they were all made by Smiths.
 
The way to connect up the Hydronic heater is to take a 't' off the engine cooling system between the engine and the 'hot' side of the heat excanger, this becomes the input to the hydronic. The output from the hydronic circulates through the matrices (sp?) and then back to another 't' piece between the 'cold' side of the heat exchanger and the engine. This allows the engine heat to circulate through the additional heater matrices and also the Hydronic will heat the engine as well. Include a calorfier, and you can have hot water as well from engine or the hydronic. On a road vehicle, the 't' pieces are put into the input and output hoses to the original in-dash heater. Connecting up this way gives the heater system enough volume to prevent the hydronic cycling on and off too quickly or going over- temperature and shutting down. Make sure that the Kw output of the matrices or radiators is more than the Kw output of the heater (say 150%), to prevent the hydronic cycling too much. Clayton Heaters of Coventry make some very nice matrix/blower units, not cheap though!

Peter
 
Peter

That's interesting - because I was advised against doing this method because of problems caused by air locks in the combined system. So I'm putting a dual coil calorifier in (which is a proper expensive pain) and keeping the systems completely independent. It also occured to me that having to heat the engine block each time that a tank full of hot water is needed would lengthen the process considerably?

rob
 
Hi, I've installed this system on medium sized buses (20 seater) and never had problems with air locks, the vehicle header tank takes care of expansion and contraction and the engine water pump pushes any air round and out of the system ( although, I would fit bleed valves at the highest points on the system). Yes the engine will absorb some heat when only running the hydronic heater, but the heat will benefit the engine by preventing condensation and making it easier to start the engine. Also the extra volume of the engine water jacket will help to stabilise the temperature of the heater circuit, helping to prevent short-cycling or over temperature shut-down. Maybe you could try connecting the heater temporarily without the twin coil calorfier to see if it performs as you want, before going for the twin-coil? Narrowboats with keel cooling do need a twin coil calorifier, otherwise, you end up trying to heat up the skin tanks!

Peter
 
Thanks Peter. I will return to this idea as I have just obtained another D5W heater. I seem to remember that there were no hoses to easilly adapt/modify on my Perkins just rubber angles and steel tubes no obvious spots to take off from.
I will give this another shot as the water system seems superior when fully installed to the blown air concept. I have a Truma gas heater installed and it is effective and quiet, I have large cylinders so gas is not and issue. But still the package appeals, engine warm up, use free engine heat through matrix when motoring, hot domestic water( free when motoring) etc...
Thanks for the advice
Peter
 
Peter

That's very helpful; thank you.

Tell me, is it necessary to have a one way valves in the supply and return from the heater unit to the hot water circuit (which would now include the engine cooling circuit) to prevent the engine water pump forcing water back through the heater? I quite like the idea of the heater plumbing being cut off from the engine circuit when motoring as it decreases the potential for cooling system leaks (when motorsailing to windward off a less shore!)

TIA

rob
 
Hi Rob, no valves are needed to isolate the hydronic heater circuit from the engine cooling system, although if you were worried about leaks, you could fit a couple of ball valves for emergencies. The hydronic heater will allow the engine water pump to circulate the cooling water through it, giving hot water and heating while the engine is running. The fault liability of any system is not determined by the number of components in it, but by the standard of the weakest component. In other words, the reliability of your cooling system won't be reduced by adding more components to it provided that they are of at least as high a quality and the standard of installation is at least as good.


Peter
 
Peter,

I have some questions!

I’m trying to interpret how I should configure my system if I were to plumb the D5W in to the engine cooling water circuit and not use my (planned) twin coil calorifier.

Having read your post a few times I’ve interpreted that I should:

1 - Tee in to pipe between engine (outbound warm water) and calorifier coil inlet. The tee off to go to the cold water inlet of the D5W.
2 - The hot water from the D5W to route first via the fan matrices and then Tee’d in to the pipe between the calorifier coil outlet and the engine.

I can see from this that the fan matrices will receive plenty of hot water – but what about the calorifier? Will that receive sufficient hot water to heat the fresh water? My logic tells me that the D5W (when no engine running) will need to push water around the fan matrix and engine block before the calorifier receives hot water. Is that right?

What I don’t understand is how the direction of the water is controlled – ie what stops it going from the hot side of the D5W then through the matrices but then backward in to the calorifier rather than onward to the engine block? Also when the hot water comes out of the engine up to the tee (as discussed above) what then stops the water ignoring the tee and heading directly in to the calorifier? Does the system need taps to balance the pressure in order to force it up the various tee’s? Or by “tee” do you mean “rediect” – and the water not having two direction options?

One other point – I have fitted a header tank for the D5W (assuming it was to be an independent systrem) but if I were to plumb in to the engine system I’d have two header tanks which presumably wouldn’t work. The engine header tank is small (about 1 litre) whereas the Eberspacher tank is 5 litres. Presumably I should do away with the engine header tank and let the Eberspacher tank handle this function? (The Eberspacher tank is above engine height).

Sorry for all the questions (some of which are no doubt stupid!) – but you answers are awaited with eagre anticipation!

Rgds

Rob
 
Hi Rob, is the calorifier already installed in your cooling system? If so, just install the D5W inline with the calorifier circulator pipes and extend the pipework to include the matrices. This way, you will get hot water and heating from either the D5W or engine (or both for a really quick warm-up). Either header tank would be ok, the eberspacher one is a good unit, designed for cooling system pressures.

On the other hand, if you already have the eberspacher header tank, you could run the D5W, calorifier and matrices as a separate system from the engine cooling system. This will prevent your worry that leaks in the additional circuit will affect the engine cooling system. The downside of that is you won't get 'free' hot water and heating from running your engine. Maybe try the separate system and only tee it in if not happy with that?

Peter
 
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