DjArgyleFan
Member
The boat I'm buying had a new Nanni diesel fitted about a year ago and has a heat exchanger on it, does this mean I can have hot water & heating on board and if so how do I do it?
Heat Exchanger
- Thread starter DjArgyleFan
- Start date
scottie
Well-Known Member
yes
you would require a calorifer which uses the engine hot water to heat atank of water connected to pressure system
see cleghorn waring web sight for further details
you would require a calorifer which uses the engine hot water to heat atank of water connected to pressure system
see cleghorn waring web sight for further details
G
Guest
Guest
I would assume that the HE is for the engine cooling so as to not have seawater pumped around the engine. You would have fresh-water and antifreeze in the egine and a system where seawater is pumped up to a HE to extract the heat from the fresh-water ....
It is possible to re-route the engine water to another HE as well to heat domestic water ....... various articles have been made in mags such as PBO .... using small domestic water tanks etc. Unless you have very good insulation and run the engine a lot - it is very limited.
It is possible to re-route the engine water to another HE as well to heat domestic water ....... various articles have been made in mags such as PBO .... using small domestic water tanks etc. Unless you have very good insulation and run the engine a lot - it is very limited.
Vara
Well-Known Member
Sorry to disagree,but most indirect cooling systems when they are connected to calorifier(HE) to provide domestic hot water work very well,and on the boats that I have had with these systems a minimal amount of engine running as in say typical power out of mooring and back in produces significant amoumts of hot water.
Essential for SWMBO.(how else could she do the washing up?)
However if boat does not already have pressurised water system quite expensive to retro fit but IMO worth every penny.
Also means that if you have shore power you can heat water using immersion heater.
Essential for SWMBO.(how else could she do the washing up?)
However if boat does not already have pressurised water system quite expensive to retro fit but IMO worth every penny.
Also means that if you have shore power you can heat water using immersion heater.
catmandoo
Well-Known Member
On this subject can any one comment on the need for an expansion tank on these indirect hot water heating systems ? Domestic systems and modern cars have them so why not boats?
My system is as described above and each day after having started with a full system the previous day I note that the level has dropped by about 1.5 inches max which I then top up . Expanded water of course goes to engine bilge etc . I think the complete hot water circuit comprising pipes to and from calorifier as well as calorifier coil itself and of course engine circuits and Bowman heat exchanger represents quite a large initial volume
So do I need to top up or not or should I fit an expansion tank and if so where do I get one to suit a boat ?
My system is as described above and each day after having started with a full system the previous day I note that the level has dropped by about 1.5 inches max which I then top up . Expanded water of course goes to engine bilge etc . I think the complete hot water circuit comprising pipes to and from calorifier as well as calorifier coil itself and of course engine circuits and Bowman heat exchanger represents quite a large initial volume
So do I need to top up or not or should I fit an expansion tank and if so where do I get one to suit a boat ?
Strathglass
Well-Known Member
It is fairly normal to fit an expansion tank.
The one I have on the calorifier side is from a Morris marina.
I too the pressure cap from the top of the calorifier and put it on the expansion box then put the stop cap from the top of the pressure cap on the calorifier. ( This cap has no thermostat parts in it )
I ran a 6mm pipe from the overflow outlet under the cap on the calorifier ( which is now at the hot water pressure ) to the inlet at the bottom of the expansion box.
I have a seperate expansion chamber within the domestic water system to allow expansion without overflowing and to allow some hysterisis within the presurised system which limits the electric pump from continuously switching off and on.
That expansion chamber came from Vetus and is just part of the plumbing. You can get them with and without internal diaphrams.
They effectively hold some air which can expand or contract as necessary. They also have a drain to release any excess water.
I have plenty of drawings and photo's I could email to you.
And I have succeeded
Cheers
Iain
The one I have on the calorifier side is from a Morris marina.
I too the pressure cap from the top of the calorifier and put it on the expansion box then put the stop cap from the top of the pressure cap on the calorifier. ( This cap has no thermostat parts in it )
I ran a 6mm pipe from the overflow outlet under the cap on the calorifier ( which is now at the hot water pressure ) to the inlet at the bottom of the expansion box.
I have a seperate expansion chamber within the domestic water system to allow expansion without overflowing and to allow some hysterisis within the presurised system which limits the electric pump from continuously switching off and on.
That expansion chamber came from Vetus and is just part of the plumbing. You can get them with and without internal diaphrams.
They effectively hold some air which can expand or contract as necessary. They also have a drain to release any excess water.
I have plenty of drawings and photo's I could email to you.
And I have succeeded
Cheers
Iain
ColinR
Well-Known Member
Do you know if I need to have indirect cooling to install a hot water system or can it work with direct sea water cooling?
Thanks,
Colin
Thanks,
Colin
G
Guest
Guest
Expansion tank ...
Most boats with HE I have seen have an exp. tank somewhere in the engine bay .... some are actually lower than the HE ...
My previuous perkins had a car type one with standard car type pressure cap and it was well below the HE on front of engine .... Funny thing was that it was normal to fill HE with top-up and not the exp. tank !
Most boats with HE I have seen have an exp. tank somewhere in the engine bay .... some are actually lower than the HE ...
My previuous perkins had a car type one with standard car type pressure cap and it was well below the HE on front of engine .... Funny thing was that it was normal to fill HE with top-up and not the exp. tank !
Strathglass
Well-Known Member
It can be done Colin.
I have seen it on a Volvo 2001 and a Buck DV36.
The water is not as hot as with a heat exchanger as the engine water temparature is limited to about 60 degrees with direct cooling.
I don't have details here but in one case (2001) the water which exited from the heat exchanger to the exhaust bend was diverted through the calorifier coil.
The calorifier can also be connected to alternative points on the engine.
Perhaps another formite will remember the details better than I can.
Iain
I have seen it on a Volvo 2001 and a Buck DV36.
The water is not as hot as with a heat exchanger as the engine water temparature is limited to about 60 degrees with direct cooling.
I don't have details here but in one case (2001) the water which exited from the heat exchanger to the exhaust bend was diverted through the calorifier coil.
The calorifier can also be connected to alternative points on the engine.
Perhaps another formite will remember the details better than I can.
Iain
capsco
Well-Known Member
Normally on a heat exchanger as long as the tube stack is covered by the coolant you do not need to fill it any further, indeed you should not fill it further, this allows the water space to expand when it heats up. so just let it find its own level, then keep an eye on the level and the temperatue until you are sure it is not going any lower.
Or rather than leave it as it is designed you could go to the trouble of fitting an expansion tank!
Or rather than leave it as it is designed you could go to the trouble of fitting an expansion tank!
Ships_Cat
Well-Known Member
I agree Capsco, that is how they are often done on many marine engines standard from manufacturer with heat exchanger. So if the engine is installed without an expansion tank it is correct - as long as the tubes are covered with coolant it is ok. If it vents coolant when engine comes up to temperature then it was overfilled with coolant and is just finding its own level, there is no need to top up the lost coolant.
With respect to a calorifier for domestic potable hot water - the easiest thing to do is to pipe the discharge of the relief valve back to one of the fresh water tanks (or into one of the tank fill pipes if closer). Saves the water if a cruising vessel and avoids water in the bilge or wherever otherwise.
John
With respect to a calorifier for domestic potable hot water - the easiest thing to do is to pipe the discharge of the relief valve back to one of the fresh water tanks (or into one of the tank fill pipes if closer). Saves the water if a cruising vessel and avoids water in the bilge or wherever otherwise.
John
cliff
Well-Known Member
[ QUOTE ]
The boat I'm buying had a new Nanni diesel fitted about a year ago and has a heat exchanger on it, does this mean I can have hot water & heating on board and if so how do I do it?
[/ QUOTE ]Heat exchanger fitted => fresh water cooler engine.
You can fit a calorifier (hot water tank) and if you read the engine manual you will see exactly where to connect the flow and return lines to the engine.
As for the calorifier, you need one with a safety blow off valve but make sure the tank (and valve) have suitable operating pressures, eg tank 50PSI and valve 30PSI with a pump pressure of 25PSI otherwise either you rupture the tank or the safety valve blows off when the fresh water pump is running.
AS for a header tank on the engine unless fitted as standard there is no need for one - the exchanger will have an air pocket to allow for expansion. IF fitting a header tank anyway be sure to fir one with the correct cap i.e. if the cap on the top of the exchanger is rated at 7PSI then a 7psi cap must be fitted to the expansion bottle. In addition, if fitting the tank to the existing blow off you will need to remove the existing "radiator cap" and remove the seal otherwise any water that passes the cap cannot return to the exchanger. Note the cap on the exchanger must seal around the top of the fitting not round the bottom (below the blow off pipe)
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"Artificial intelligence is no match for natural stupidity"
The boat I'm buying had a new Nanni diesel fitted about a year ago and has a heat exchanger on it, does this mean I can have hot water & heating on board and if so how do I do it?
[/ QUOTE ]Heat exchanger fitted => fresh water cooler engine.
You can fit a calorifier (hot water tank) and if you read the engine manual you will see exactly where to connect the flow and return lines to the engine.
As for the calorifier, you need one with a safety blow off valve but make sure the tank (and valve) have suitable operating pressures, eg tank 50PSI and valve 30PSI with a pump pressure of 25PSI otherwise either you rupture the tank or the safety valve blows off when the fresh water pump is running.
AS for a header tank on the engine unless fitted as standard there is no need for one - the exchanger will have an air pocket to allow for expansion. IF fitting a header tank anyway be sure to fir one with the correct cap i.e. if the cap on the top of the exchanger is rated at 7PSI then a 7psi cap must be fitted to the expansion bottle. In addition, if fitting the tank to the existing blow off you will need to remove the existing "radiator cap" and remove the seal otherwise any water that passes the cap cannot return to the exchanger. Note the cap on the exchanger must seal around the top of the fitting not round the bottom (below the blow off pipe)
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catmandoo
Well-Known Member
I did not ask the question without some fore knowledge and thought . I used to design heat exchangers.
An engine without a calorifier is one thing but when introduced to a calorifier circuit some metres away from the engine then this increases the volume of the system and hence the amount of water expanded .
I had thought about just leaving it as is and noting the level at which the heat exchanger level stailised but this is dificult to measure without a dip stick and access to the top of the engine involves removing a heavy casing So a practical approach could be to look at a plastic see through tank with high and low markings at an accesible location .However since this could be construed as an overkill I was curious to see if others had this system since my boat was at least 27 yrs old
An engine without a calorifier is one thing but when introduced to a calorifier circuit some metres away from the engine then this increases the volume of the system and hence the amount of water expanded .
I had thought about just leaving it as is and noting the level at which the heat exchanger level stailised but this is dificult to measure without a dip stick and access to the top of the engine involves removing a heavy casing So a practical approach could be to look at a plastic see through tank with high and low markings at an accesible location .However since this could be construed as an overkill I was curious to see if others had this system since my boat was at least 27 yrs old
ditchcrawler
Well-Known Member
I have a Nanni 2.50 HE on my boat with a calorifier & it provides hot water very well to sink & heads & as COLMCE says only requires a few minutes engine running to do so.
It works for me.
It works for me.
catmandoo
Well-Known Member
Mine works OK too both from engiene heat and also calorifier. Insulation keeps waterhot for almost 2 days
