Thermocycling questions

[fudd]

Morning.

I'm ready to fit the rads. There will be one rad 6m from the boiler and one 8m away.

4.5m from the boiler is the calorifier. It's horizontal and on the other side of the boat.

What is the best way to plumb it in?

I don't mind putting a pump in for the hot water side but I don't know the best way to plumb it in.

Is there a maximum rise for the flow for the rads?

What is the best way to get the return from the rads back, level or dropping?

If like to box the pipes in, so is there a problem if I solder the joints rather than use compression fittings? I don't want to loose too much space behind the panelling.

Plus I'd like an answer for anything else I've forgotten!

In the mean time I'll trawl the forum.

Steve P

Edited September 19, 2013 by fudd

[The Bagdad Boatman (waits)]

Solder is ok for water but not for gas or fuel. because solder joints may crack with viberation. If the pipe from the heater goes up then cold water will be drawn into the bottom of the heater creating a flow hot water is lighter than cold. A pump is switched on by a thermostatic switch usualy on the hot pipe above the heater. if you have an inverter then use a 240v heating pump on the cold supply to the heater. Better to use dual pipe system as in a house and restrict flow with valves.

[fudd]

Morning.

I'm ready to fit the rads. There will be one rad 6m from the boiler and one 8m away.

4.5m from the boiler is the calorifier. It's horizontal and on the other side of the boat.

What is the best way to plumb it in?

I don't mind putting a pump in for the hot water side but I don't know the best way to plumb it in.

Is there a maximum rise for the flow for the rads?

What is the best way to get the return from the rads back, level or dropping?

If like to box the pipes in, so is there a problem if I solder the joints rather than use compression fittings? I don't want to loose too much space behind the panelling.

Plus I'd like an answer for anything else I've forgotten!

In the mean time I'll trawl the forum.

Steve P

By the way, is there a reason why the radiators can't be turned round 90 degrees? It would make the installation easier and possibly work better. Just realised I'm typing rubbish.

I retract that last edit.

Edited September 19, 2013 by fudd

[Alastair]

What bagman said. I'd suggest using plastic pipe rather than copper - much easier to fit, repair and appearance won't matter if you are boxing in.

[fudd]

What bagman said. I'd suggest using plastic pipe rather than copper - much easier to fit, repair and appearance won't matter if you are boxing in.

I spoke to my household heating engineer and he said use copper. I'd rather use it anyway. I think if it does go a bit wrong it would hold up a bit better.

[bottle]

but he was talking about a house, boats are different.

 

Mine is boiler driven and pumped but all hidden pipework, under the floor is plastic and only the risers to the radiators are copper.

 

ps. check out the cost of copper and plastic. and probably less joints with plastic.

Edited September 19, 2013 by bottle

[fudd]

but he was talking about a house, boats are different.

 

Mine is different to what you are proposing, in the fact that is boiler driven and pumped but all hidden pipework, under the floor is plastic and only the risers to the radiators are copper.

 

ps. check out the cost of copper and plastic.

A couple of experts here recommended using copper. I know it's expensive but probably trouble free.

Why in this respect is a house different from a boat?

Also the push fit fittings are bulky. I'd lose a bit too much room down the corridor.

Edited September 19, 2013 by fudd

[bottle]

Boats move, not just through the water, having said that a friend had copper mounted at skirting board level and he polished it. he had no problems.

 

Plastic just like copper is trouble free except when they go wrong.

 

Agreed push fittings are bulky but mine are all under the floor, joins are under cupboards etc with hatches for access.

 

Just putting other options to you, it is your decision.

[fudd]

Boats move, not just through the water, having said that a friend had copper mounted at skirting board level and he polished it. he had no problems.

 

Plastic just like copper is trouble free except when they go wrong.

 

Agreed push fittings are bulky but mine are all under the floor, joins are under cupboards etc with hatches for access.

 

Just putting other options to you, it is your decision.

That's the difference. Mine will hopefully cycle itself. I can't go under the floor for that reason.

Copper can't go wrong like plastic can. I've been told it can sag and that could cause problems with it cycling. Dunno.

Anyway I've gone and bought the pipe. 6 lengths 28mm for £111. Good job I'm not doing a house.

Also, the fittings are much cheaper. I bet it doesn't make much difference in the long run.

Edited September 19, 2013 by fudd

[bottle]

 

I've been told it can sag

 

ooer!!

 

True it can and would therefore need more support.

 

You did mention that you would not mind fitting a pump, you may like to go with the gravity, thermo system for now but put in the option of fitting a pump later.

 

I expect you already thought of that.

[fudd]

 

ooer!!

 

True it can and would therefore need more support.

 

You did mention that you would not mind fitting a pump, you may like to go with the gravity, thermo system for now but put in the option of fitting a pump later.

 

I expect you already thought of that.

I would fit a pump but only to heat the water. I would connect it to the stat on the calorifier so that when it came up to temperature it would switch itself off. The main circuit should still work, he said, hopefully.

[ditchcrawler]

If you are doing a thermo system remember when setting the pipes out the floor of the boat is probably not level end to end, so make sure you have enough rise on the pipes.

[bottle]

Post #11

 

not sure how that would work unless the two systems were totally separate but I am sure your heating engineer could help there.

[fudd]

 

If you are doing a thermo system remember when setting the pipes out the floor of the boat is probably not level end to end, so make sure you have enough rise on the pipes.[/quot

 

With a full tank of water our floor has a fall of 1/100. We have plenty of room for rise etc.

Post #11

 

not sure how that would work unless the two systems were totally separate but I am sure your heating engineer could help there.

He reckons it could be ok. It may well have to be a separate circuit though.

[bottle]

or a change over valve which effectively makes them separate but you could not have them running at the same time.

[fudd]

or a change over valve which effectively makes them separate but you could not have them running at the same time.

Thinking about it, if the main circuit was thermocycling and I plumbed a pump in somewhere, then when I wanted hot water I could turn on the pump. Just because it has the capability to thermocycle it should still be capable of being pumped, or maybe not!

[bottle]

Yes the thermo cycle part could be pumped and it may make it more efficient and you do not want to hear this it could be run in 15mm.

 

edit: it would have to be permanently pumped to use 15mm

Edited September 19, 2013 by bottle

[fudd]

Yes the thermo cycle part could be pumped and it may make it more efficient and you do not want to hear this it could be run in 15mm.

 

 

 

edit: it would have to be permanently pumped to use 15mm

Aha. But I only want to run the pump if and when I want hot water.

[canals are us?]

What I would do is run 28mm copper pipe to the rads on gravity. Gravity flow pipe rising up along the length of boat and mount the rads as high as possible and run the return pipe if possible with a slight fall to the stove. Use full bore lever valves instead of rad valves to turn on/off the rads if required. You would find the layout easier using 300or 400mm height rads with 4 tappings and tee off the flow to each rad. Top in bottom opposite return.

 

For the calorifier I would use either copper pipe or plastic and tee off the back of the pipes behind the stove and run this in 15mm and put a pump on it to circulate this circuit.

Feed and expansion tank at the highest rad end. Auto air vent on calorifier end depending on layout to expel air while filling etc.

Please remember there are very many variables in design and boat layout so designs will vary to achieve the right result.

 

Uploaded with ImageShack.us

 

James

Edited September 19, 2013 by canals are us?

[fudd]

What I would do is run 28mm copper pipe to the rads on gravity. Gravity flow pipe rising up along the length of boat and mount the rads as high as possible and run the return pipe if possible with a slight fall to the stove. Use full bore lever valves instead of rad valves to turn on/off the rads if required. You would find the layout easier using 300or 400mm height rads with 4 tappings and tee off the flow to each rad. Top in bottom opposite return.

 

For the calorifier I would use either copper pipe or plastic and tee off the back of the pipes behind the stove and run this in 15mm and put a pump on it to circulate this circuit.

Feed and expansion tank at the highest rad end. Auto air vent on calorifier end depending on layout to expel air while filling etc.

Please remember there are very many variables in design and boat layout so designs will vary to achieve the right result.

 

Uploaded with ImageShack.us

 

James

Edited September 19, 2013 by fudd

[fudd]

The boiler is 8000 BTU. what should the radiators be rated at? I only want single panels. Two radiators need to be about 600 x 2000 to get anywhere near 8000 BTU. Or do I not have to worry too much? Thanks for your help so far.

Edited September 20, 2013 by fudd

[Beaker]

.

 

Pardon?

[fudd]

 

Pardon?

Sorry

[canals are us?]

The boiler is 8000 BTU. what should the radiators be rated at? I only want single panels. Two radiators need to be about 600 x 2000 to get anywhere near 8000 BTU. Or do I not have to worry too much? Thanks for your help so far.

 

Ideally your rads do need to equate to the boiler size as if you had a big fire going the boiler could boil. Could you install another rad on the pumped calorifier circuit to the bathroom?

What stove are you installing?

How about installing doubles rads but single convector rather than double rads but double convector if depth is an issue.

 

James

[fudd]

 

Ideally your rads do need to equate to the boiler size as if you had a big fire going the boiler could boil. Could you install another rad on the pumped calorifier circuit to the bathroom?

What stove are you installing?

How about installing doubles rads but single convector rather than double rads but double convector if depth is an issue.

 

James

Hello James. I've managed to get the out put to nearly 6000 BTU without the pumped circuit.

Doubles would be too deep. I've managed to get a double in the engine room and two more 300x800 singles in the corridor and bathroom.