Two calorifiers

[Bromleyxphil]

Hi my kitchen sink and shower are quite a long way apart in the design so I am thinking of a two calorifier System one sited behind the sink and one sited next to the shower.  I will plumb the heater side from the engine and diesel heater in series, pipe the cold feed from a T between the two possibly with a non return just before each calorifier.  Will it work?  I hope it will lessen the cold run before the hot hits the tap so save water.

phil

[ditchcrawler]

9 minutes ago, Bromleyxphil said:

Hi my kitchen sink and shower are quite a long way apart in the design so I am thinking of a two calorifier System one sited behind the sink and one sited next to the shower.  I will plumb the heater side from the engine and diesel heater in series, pipe the cold feed from a T between the two possibly with a non return just before each calorifier.  Will it work?  I hope it will lessen the cold run before the hot hits the tap so save water.

phil

I would think so, some calorifiers have a built in non return valve. I take it the galley one would be a small one. Just think about the space they take up.

[nb Innisfree]

29 minutes ago, Bromleyxphil said:

Hi my kitchen sink and shower are quite a long way apart in the design so I am thinking of a two calorifier System one sited behind the sink and one sited next to the shower.  I will plumb the heater side from the engine and diesel heater in series, pipe the cold feed from a T between the two possibly with a non return just before each calorifier.  Will it work?  I hope it will lessen the cold run before the hot hits the tap so save water.

phil

I installed two cals on Innisfree, one each side of boat, one next to the kitchen sink and one in the lounge up against the wall which formed the wall of the next door shower. Quick delivery of hot water, the shower took about 3-4 secs. I arranged a flow and return heating run down each side of the boat with cals connected in parallel same as the rads, one downside was having to turn each rad off or on at onset and end of winter.

I didn't bother with NRVs instead I arranged a separate teed off feed from each cold supply to the cals, long enough to accommodate the hot water expansion so that it didn't reach back to the cold feed for the sink taps, that way the accumulators doubled up as expansion vessels. 

Edited November 10, 2017 by nb Innisfree

[Robbo]

Might be easier to just have a recirculation pump? Would be less plumbing.

 

example diagrams at this link..

http://www.houseneeds.com/learning-center/plumbing-supplies-install/recirculating-pumps-traditional-install

Edited November 10, 2017 by Robbo

[ditchcrawler]

29 minutes ago, Robbo said:

Might be easier to just have a recirculation pump? Would be less plumbing.

 

example diagrams at this link..

http://www.houseneeds.com/learning-center/plumbing-supplies-install/recirculating-pumps-traditional-install

Less or more, you need a flow and return to each tap, the water would constantly bee getting cooler unless the lagging was very good and the pump would need to run 24/7 OK in a house with a boiler and mains electricity. The easiest way is just to waste a lt. of water every time you fill the sink.

[Robbo]

9 minutes ago, ditchcrawler said:

Less or more, you need a flow and return to each tap, the water would constantly bee getting cooler unless the lagging was very good and the pump would need to run 24/7 OK in a house with a boiler and mains electricity. The easiest way is just to waste a lt. of water every time you fill the sink.

Some can use the cold water pipe as a return and only pump if temperature is low at the tap or/and on a timer - or you could just run the pump a few seconds before you turn the hot water tap on.

[Bromleyxphil]

So the upshot is that it should work.  My preferred pump is one of these https://www.mackengineering.co.uk/r3426-344a-24v-triplex-pressure-controlled-pump.html. I have used them before and found them to be bombproof with no need for an accumulator in the system.

[nb Innisfree]

But with no accumulator or expansion vessel how can the expansion of calorifier hot water be accommodated? 

ETA: Ignore that, only elimination of accumulator mentioned, not expansion  vessel. 

Edited November 10, 2017 by nb Innisfree

[Sea Dog]

Two cauliflowers is just showing off - a bit like Arthur 'two sheds' Jackson.

[MtB]

4 hours ago, Bromleyxphil said:

 I will plumb the heater side from the engine and diesel heater in series

 

I don't think that's a good idea. 

When you run the diesel heater it will warm up the engine as well as the calorifier, both very slowly. 

[nb Innisfree]

55 minutes ago, Sea Dog said:

Two cauliflowers is just showing off - a bit like Arthur 'two sheds' Jackson.

At my time of life what else is there? 

[nb Innisfree]

22 minutes ago, Mike the Boilerman said:

 

I don't think that's a good idea. 

When you run the diesel heater it will warm up the engine as well as the calorifier, both very slowly. 

On 'two cals' Innisfree I did just that but ran it through a diverter valve so I could pre-heat engine only, heat cals only, heat rads only, heat call and rads, or, heat all that lot with engine instead!

I like complicated.  

 

 

[MtB]

21 minutes ago, nb Innisfree said:

On 'two cals' Innisfree I did just that but ran it through a diverter valve so I could pre-heat engine only, heat cals only, heat rads only, heat call and rads, or, heat all that lot with engine instead!

I like complicated.  

 

But that means you didn't connect them up in series as the OP is planning.

[nb Innisfree]

11 minutes ago, Mike the Boilerman said:

 

But that means you didn't connect them up in series as the OP is planning.

Rads and cals were in parallel as in conventional CH but they were either in series with engine or engine was isolated depending on diverter valve. 

[ditchcrawler]

I read it that the OP was going to connect say the bottom coils of both calorifiers in series with the engine and the top two in series with the boiler which as far as boiler/engine  interaction is the same as one twin coiled calorifier

[nb Innisfree]

4 minutes ago, ditchcrawler said:

I read it that the OP was going to connect say the bottom coils of both calorifiers in series with the engine and the top two in series with the boiler which as far as boiler/engine  interaction is the same as one twin coiled calorifier

Difficult to be sure without a diagram, I used to post pics from Paint via Photobucket before they started charging an arm and a leg. 

[Bromleyxphil]

1 hour ago, ditchcrawler said:

I read it that the OP was going to connect say the bottom coils of both calorifiers in series with the engine and the top two in series with the boiler which as far as boiler/engine  interaction is the same as one twin coiled calorifier

That’s about the size of it........no one think it won’t work?

thanks all for your answers

Phil

[cuthound]

It definitely works. My 60 foot boat was accidentally plumbed with the two calorifier coils in series when I bought it. It had recently had a replacement calorifier.

We picked it up on a hot June day and it was unbearably hot in the cabin until I valved the radiators off.

I replumbed the calorifier because I was concerned about the engines water pump having to pump it's coolant around the central heating circuit.

[Onewheeler]

19 hours ago, Mike the Boilerman said:

 

I don't think that's a good idea. 

When you run the diesel heater it will warm up the engine as well as the calorifier, both very slowly. 

But it would make the engine start quickly!

[nb Innisfree]

59 minutes ago, Onewheeler said:

But it would make the engine start quickly!

it's great in cold weather and extends engine service life considerably. 

[Bromleyxphil]

On 10/11/2017 at 12:55, nb Innisfree said:

But with no accumulator or expansion vessel how can the expansion of calorifier hot water be accommodated? 

ETA: Ignore that, only elimination of accumulator mentioned, not expansion  vessel. 

Excuse my ignorance but what is the difference between an accumulator and an expansion vessel

[Robbo]

1 minute ago, Bromleyxphil said:

Excuse my ignorance but what is the difference between an accumulator and an expansion vessel

I think the accumulator has a bag in it and can pressurised to a certain level using a pump.  Expansion vessel is more for hot water side.   Don’t quote me on the above tho!

[Bromleyxphil]

It’s just I have used these in two camper systems the latest with a calorifier and gas heater in the system with no expansion or accumulator and they don’t cycle or have an issue with expansion.

[Robbo]

13 minutes ago, Bromleyxphil said:

It’s just I have used these in two camper systems the latest with a calorifier and gas heater in the system with no expansion or accumulator and they don’t cycle or have an issue with expansion.

An accumulator after the pump reduces cycling of the pump as most pump just at a certain flow.  So if you have a tap on low the pump will be off/on/off/on/off.   The accumulator keeps a constant pressure on the system (and supply of water so think of it as a buffer) so the pump has longer cycles (bigger the accumulator the longer the cycle).    Some pumps have variable flow so don't require a accumulator.

An expansion tank is for the hot water side and is recommended if you have something like a calorfier as the large water in the tank heated up will increase the pressure and make the PRV leak, etc.   The expansion tank is just takes the extra instead.   As most gas heater systems heat the water as you turn the tap on there is no hot water getting heated in a tank to increase the pressure, etc.   An expansion tank is required for central heating if a closed system (ie no header tank).

Edited November 15, 2017 by Robbo

[MtB]

43 minutes ago, Robbo said:

I think the accumulator has a bag in it and can pressurised to a certain level using a pump.  Expansion vessel is more for hot water side.   Don’t quote me on the above tho!

 

No, they are identical structurally. The difference is in the use to which you are putting them. 

In the world of plumbing the two terms are used interchangeably. Only here in boat world do people seem to draw a distinction. The difference in function is quite subtle.

(Both have the neoprene bag inside, I forgot to say.)