Calorifier location

[monito]

Hi everyone

 

I am fitting out a new sailaway, semi-trad stern.

The plan was to put the calorifier under the stairs at the stern end of the cabin area.

I came across the idea yesterday of putting it in the engine space.

 

This would save us the space under the stairs that could be used for storage,

but I am a little concerned that as the engine space will be a lot colder than

the boat we could run into trouble with cold, especially in winter (the idea is

to go liveaboard once fit out completed. (yes I know its not easy to find a place))

 

Do any of you have any opinions on if locating the calorifier inside or 'outside'

will have any affect on how long the water stays hot and/or dangers from

frost ?

 

Thanks

 

Monito

[NB Willawaw]

I have mine in my back cabin where I can get at the element if I need to. We have a generator onboard and can heat the water that way or on shore power (as well as engine/Eberspacher). It (the calorifier) doesn't take up much room and I can replace the element/thermostat if I need to (we have hard water where we normally winter on the Stort and Lee and limescale is a problem). I have seen calorifiers under the dinette or bunks in some boats which seems a good use of space.

I would imagine that the engine space might not be such a good choice due to frost. I guess it depends on whether the boat is left unattended for long periods of time during the winter; would you drain the fresh water system down when laid up ?

Good question !

 

Mark

 

NB Willawaw

 

Kings Langley GU Northbound

[Richard Bustens]

Hi I'm putting ours in the bathroom with a airing cupboard over it like a house one, if you are going to be a live aboard you will need to have some means of airing your bits and bobs.

[monito]

Hi I'm putting ours in the bathroom with a airing cupboard over it like a house one, if you are going to be a live aboard you will need to have some means of airing your bits and bobs.

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Thought about that a while back. Seems like a good idea providing the bathroom is at the stern of the boat, or you'r just using a single coil calorifier. I am thinking that with a twin coil if your bathroom is in the middle of the boat then in the summer you will be running your engine hot water down the boat and heating the inside up. Might not make much difference but boats can be quite warm enough in the summer I recon. Just my take at the moment.

 

Have you put your in yet or are you still fitting out ?

Let us know how it goes in the summer at any rate.

 

I would imagine that the engine space might not be such a good choice due to frost. I guess it depends on whether the boat is left unattended for long periods of time during the winter; would you drain the fresh water system down when laid up ?

We're hoping never to leave it for long, but if we were to then I would drain it.

[Richard Bustens]

Hi Monito

Bathroom next to engine room but you can always insulate the pipes to stop heat

[NB Willawaw]

Going slightly off at a tangent, I would suggest that you consider either installing two water pumps (main and back-up) or carry a spare.

My water pump packed up and I had no running water for a few days (had to live out of bowls of water filled from BW taps as I cruised - very inconvenient). Also, the toilet wouldn't flush. Apart from the engine, I reckon the water pump is the next most useful bit of kit on a boat. I now carry a complete spare pump so that it won't happen to me again. However, I met a fellow boater who had two wired in circuit with a changeover switch. If he had a problem with one he would just isolate the faulty one and throw the switch !

[DHutch]

Also, ive heard that you should put your calorifier higher up then the engine as well, so the all the heat doesnt cycal back into the engine over night, which would make sence i guess, although i have not experience of calorifiers and IC engines.

 

- also, make sure its well lagged, becuase there nothing nicer than a warm wash in the morning, and if its not lagged, you wont be having one during the summer. (unless your planning on using an electric heater?)

 

 

daniel

Edited January 31, 2005 by dhutch

[sbillis]

Also, ive heard that you should put your calorifier higher up then the engine as well, so the all the heat doesnt cycal back into the engine over night, which would make sence i guess, although i have not experience of calorifiers and IC engines.

 

- also, make sure its well lagged, becuase there nothing nicer than a warm wash in the morning, and if its not lagged, you wont be having one during the summer. (unless your planning on using an electric heater?)

daniel

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Just a thought. If the calorifier is higher than the engine how do you keep the primary (engine coolant flow and return) full when you take off the coolant filler cap on the engine?

 

Simon

nb Bulrush

[David Schweizer]

Also, ive heard that you should put your calorifier higher up then the engine as well, so the all the heat doesnt cycal back into the engine over night, which would make sence i guess, although i have not experience of calorifiers and IC engines.

 

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If you can fit a one way valve into the hot water flow pipe it will stop any back flow of heat overnight.

[dor]

Calorifiers I've seen in the engine 'ole have all been horizontal ones.

I understand that horizontal cylinders have two faults:

 

1: they don't get as much water hot as a vertical one for the same size,

2: they are prone to back-flowing when the engine cools.

 

A NRV can help with point 2, but point 1 is a bit trickier to overcome.

[Richard Bustens]

I can not quite see how a NRV can stop it as surley it will just go the other way . or am i missing something?

[Tommo]

Hi Monito

 

I have had both vertical and horizontal cylinders, so perhaps I should put in my pennyworth. Mine is currently laying horizontal under the floor in the boatman’s cabin, similar to what your proposing but not quite as cold, it is though, probably 18ft away from the shower and 32ft away from the galley sink with no major drawbacks.

I can see the theory see why a horizontal cylinder should not store as much hot water as a vertical one, but in practice I have not really noticed any difference. The problem of reverse circulation was a problem, wake up in the morning to a warm engine and tepid water, I solved that 100% with a motorised valve, which opens and closes with the ignition switch. I was advised not to restrict the flow with a non-return valve.

As I see it your main problem would be frost protection, but if are going to be connecting to some form of automatic heating Alde/Mikuni etc you should be OK.

A cylinder does take up a lot of space, if you can “loose” it out of the way then I think that’s a good idea. There is not that much heat given off by a well-insulated cylinder so you wont miss out that way.

 

Tommo

[Richard Bustens]

Yes the motorized valve sounds a better bet, i still think that the water would continue to flow if you only use a one way valve

Edited February 1, 2005 by Richard Bustens

[Big COL]

Yes the motorized valve sounds a better bet, i still think that the water would continue to flow if you only use a one way valve

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Richard

 

Use two then. One valve will do the job. provided its fitted in the right position.

Edited February 1, 2005 by Big COL

[Richard Bustens]

How ?

You still have a circular circuit but the ability for one way travel only so it still can flow from the cal to engine, as with the shut off valve it can not unless open, and if it is only open when the engine is running that would be good

[NB Willawaw]

I believe a vertical calorifier holds its heat better than a horizontal one. This is because, as heat rises, by morning the top layer of water is warmer than the bottom layers. On a horizontal calorifier, there is a greater surface area, therefore heat is lost quicker.

 

If you use a vertical one and the engine coolant inlet coil into it is higher than the engine, presumerably you would need an (even higher) header tank to be able to fill the circuit ? In this event, I presume that the inactive water pump (engine switched off) on the engine prevents the coolant trying to overflow out of the filler hole cap when the cap is removed ? If this holds water (excuse the pun), then the hot water should stay up in the "coils" when the engine is switched off.

 

Mine seems to work, but not sure how. The above is purely my conjecture. Thoughts appreciated.

 

Mark

 

NB Willawaw

 

Cowroast GU (moored)

[Big COL]

How ?

You still have a circular circuit but the ability for one way travel only so it still can flow from the cal to engine, as with the shut off valve it can not unless open, and if it is only open when the engine is running that would be good

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The circulation continues only while the water in the engine is hotter than in the cal, given that the cal is insulated, and the engine is not, the engine water temp soon drops below that of the cal, and a reverse flow can occur, not always it varies with different engines, its this reverse flow that you need to stop. fitting a one way valve in the flow from the engine to the cal will stop this.

[Guest]

Although i haven't comissioned the cal yet, I have taken the pipework from the engine deliberately higher than the engine or the (horizontal) cal to try and prevent backflow. What are my chances?

[Alan Saunders]

Although i haven't comissioned the cal yet, I have taken the pipework from the engine deliberately higher than the engine or the (horizontal) cal to try and prevent backflow. What are my chances?

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So long as the heat sink is higher than the heat supply, thermal flow will be established. Smaller, longer pipes will provide more resistance to flow. My calorifier is effectively at the same level as the engine with two 15mm, 6 foot pipes. The water is cold in the morning; engine life is extended as it is preheated by the Alde!

 

I had a concern when installing solid fuel central heating in a house. A heating engineer assured me that running 22mm pipes up to the ceiling void, into the utility room and back down to the heat-sink radiator would work, so long as the radiator was higher than the boiler. It was also best to provide a slope on the 'horizontal' sections. I set the bottom of the radiator at about the level of the top of the boiler and it worked fine although it took some time for the thermal flow to establish.

 

So, other than increasing the length, it makes no difference however high you run the pipes. However, providing 'downhill' runs in the 'horizontal' section may prevent the establishment of thermal flow.

 

I also installed one-way valves to prevent thermal flow in the main pumped circuit. The thermal flow is inadequate to open the valve but, hopefully, the circulating pump will. I don't think the little circulator in my Alde would open such a valve.

 

If your calorifier is above the level of the engine you will need a temporary header tank attached to the engine coolant filler to fill the calorifier coil and an air-bleed at the high point. So long as the calorifier connections remain below the level of coolant in the engine it will not empty when you remove the filler cap.

 

Alan

[dor]

My (vertical) calorifier sits on the floor just forward of the rear bulkhead. The pipes go through the bulkhead to the engine on the other side (cruiser stern). The engine if anything is a little higher than the tank coil.

 

I do not get any back flow that I can discern and have plenty of hot water in the morning.

 

Other people have similar configurations and do get backflow.

 

Such is physics.

[DaveR]

I have just evicted the horizontal calorifier from the engine room as it was for ever air locking. This probably because the base of the tank was located about 9 inches above the top of the engine.

 

I put in a 50ltr vertical cylinder and now have loads of hot water but with the tank in the engine room these cold mornings the hot water is just about off cold so that when brushing my teeth they don't get out and wave!

 

I am now considering whether to (next autumn) move the tank into the boat and into the airing cupboard. This would require a circulation pump from the engine jacket water - so I guess I am going to have to be careful about the flow rate of the pump. Can I get away with a central heating pump set on the lowest rate or would a magnetic drive 12 volt pump be better?

Thanks

 

Dave R

[ChrisPy]

I have just evicted the horizontal calorifier from the engine room as it was for ever air locking. This probably because the base of the tank was located about 9 inches above the top of the engine.

 

I put in a 50ltr vertical cylinder and now have loads of hot water but with the tank in the engine room these cold mornings the hot water is just about off cold so that when brushing my teeth they don't get out and wave!

 

I am now considering whether to (next autumn) move the tank into the boat and into the airing cupboard. This would require a circulation pump from the engine jacket water - so I guess I am going to have to be careful about the flow rate of the pump. Can I get away with a central heating pump set on the lowest rate or would a magnetic drive 12 volt pump be better?

Thanks

 

Dave R   

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I hope you don't feel the need to brush your teeth in the engine room??

[Richard Bustens]

That's better than scratching your arse in public

[ChrisPy]

That's better than scratching your arse in public

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ehhh???? ....... what's wrong with doing that?