Hot Water Heating/Calorifier/Engine Options/ideas

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mattnj

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Hi,

Is it possible/practical to have a hot water (eber hydronic) system connected inline with coolant system for hot water and heating for free (when engine is running) and on the eber hydronic when the engine is off?

Thanks
 
Probably, but it's highly unlikely that the engine circulating pump would be man enough to circulate the coolant all the way round your heating system. Depending on how complex your system is, I would expect you would need another pump.
Having said that, the pump on my VP MD22, seems quite happy to pump through a calorifier, and a matrix for blown hot air.

Presumably it would need some sort of controlled bypass, so that when using Eber, the heat didn't go through the engine.
 
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It should certainly be possible, though there are some possible difficulties in getting the balance right. Apart from size/output, there are two main design tpes of hydronic unit. One is a stand alone heater which incorporates a circulation pump of its own and the other type is an auxiliary automotive heater which is used in-line in a vehicle's heater loop. Of course a separate pump may be used to pump the circuit when the auxiliary type is used but, as already said, the extended circuit may be too much for the engine's circulation pum, so a variety of circuits have been used to close off the extra loop created by the Hydronic when it is not in use. A look through the installation manuals should give you some ideas - Suitable sites to access the manuals can be found on the Le Tonkinois website.

It is quite probable that the load of the calorifier will be too small and the heater will cycle rapidly, not good for longevity. Most boat installations are combined heating and hot water systems to balance the load with one heat outlet permanently on, such as a heated towel rail. It would be much simpler to use a twin coil calorifier and keep the Hydronic system separate from the engine's circuit.

Rob
 
mattnj said:
Hi,

Is it possible/practical to have a hot water (eber hydronic) system connected inline with coolant system for hot water and heating for free (when engine is running) and on the eber hydronic when the engine is off?

Thanks
Click to expand...
You could valve it in. Y valve would allow engine or hydronic to heat the calorifier. Top tip, go to the scrapoy, rover 75 diesel, they have the webasto fitted as std, they also have a circulation pump fitted with them. The tick tick pump is under the offside rear arch. I got one for £40. They are simple to wire in, they dont have the complications of cannbus. Just a simple on off switch controls them with a built in thermostat. Dont know what the temp is set at, google is your friend
S
 
It's possible, but unnecessarily complicated. Hot water is free anyway when the engine's running, so your only gain would be a bit of heating, which usually wouldn't be in great demand when the boat's moving. Probably much easier and cheaper just to use an Eber when you need it.
 
pvb said:
It's possible, but unnecessarily complicated. Hot water is free anyway when the engine's running, so your only gain would be a bit of heating, which usually wouldn't be in great demand when the boat's moving. Probably much easier and cheaper just to use an Eber when you need it.
Click to expand...

I think if you sailed off-season in a relatively cold country, either in a motor boat or if motoring in a yacht with an enclosed helm, you would quite appreciate "a bit of heating". I achieve it by passing waste heat from the engine through a matrix, (from a Transit Van), and using some ducting and a fan. Toasty.
 
I like that! However after seeing 32deg C in Faro inside the boat I think I will pass till we get home!
S
 
A friends boat on the west coast of Scotland, bought secondhand from Sweden has such a system. Hot water is heated by the engine when running and when moored the Webasto heater does both hot water and heating via finned radiators under the bunks. It's a hot water heating system not blown hot air. Lovely and warm. The calorifier has two heating coils.
 
Phoenix of Hamble said:
It would be cheaper to buy a twin coil calorifier rather than muck about with Y valves etc!
Click to expand...

Except that wouldn't do what I asked for....which was run heating off the engine when that's running.

vyv_cox said:
I think you should. Perhaps you might try Eberspacher Hydronic? Dozens of them. Here's one, not exactly what you want but I don't have time to work it out for you.

http://www.eberspacher.com/download...f_ebuk/hydronic_d4-d5_marine_heater_22298.pdf
Click to expand...

mmm, read that, no mention of integrating with engine cooling (other than a few words of not recommended) not to worry, I will keep searching.
 
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mattnj said:
Except that wouldn't do what I asked for....which was run heating off the engine when that's running.



mmm, read that, no mention of integrating with engine cooling (other than a few words of not recommended) not to worry, I will keep searching.
Click to expand...
You will have to valve it otherwise you will heat the engine up when it isnt running. Waste of fuel!
S
 
mattnj said:
mmm, read that, no mention of integrating with engine cooling (other than a few words of not recommended) not to worry, I will keep searching.
Click to expand...

Can we assume you still have a Moody 36? If so, you need to consider just how much heat your engine can afford to lose. Running the coolant through a calorifier plus matrix heaters may well mean that your engine will struggle to reach operating temperature - leading to excess fuel consumption and excess wear.

If you install a Hydronic system, you know it will work as a standalone, and won't use a huge amount of fuel. I think your plan won't work very well, however if you do go ahead, consider getting stacked Y-valves which operate simultaneously so there's no chance of setting the valves wrongly.
 
Ok. Fair enough....if it cant be done (doesnt seem that difficult...but hey) i will go for a straight hydronic and a couple of matrix fans. I have to take a feed for a new calorifier and ruN pipes, so thought it was worth investigating.
 
mattnj said:
Ok. Fair enough....if it cant be done (doesnt seem that difficult...but hey) i will go for a straight hydronic and a couple of matrix fans. I have to take a feed for a new calorifier and ruN pipes, so thought it was worth investigating.
Click to expand...

It can be done. I cannot find the instructions on-line at present but I have them as a pdf on my iPad. Eberspacher sell various kits of non return valves and thermostats that avoid the obvious problems of passing hot water through a stationary engine. Everything described in the instructions. PM me an email address and I will send it.
 
mattnj said:
Ok. Fair enough....if it cant be done (doesnt seem that difficult...but hey) i will go for a straight hydronic and a couple of matrix fans. I have to take a feed for a new calorifier and ruN pipes, so thought it was worth investigating.
Click to expand...
My MD22 heats the calorifier up so much that it is scalding after an hour or so of motoring. I wouldnt worry about lack of heating capacity of the engine! As I said in a simplistic way you will have to valve it tho. Vyv has the automatic version, if its Eber it wont be cheap. My veiw is the cheap option. On mine I could put two Y valves in and it would work. I would buy a cheap scrappy Webasto, two y valves and plumb it in.
S
 
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