Wet heating insulation

Nov 6, 2005
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Hi All,

Assuming the labour costs are zero is it worth insulating pipes and adding reflective screens behind radiators?
Many caravans run the hot and cold water pipes next to the Alde heating pipes - so worth insulating them with domestic pipe insulation to prevent heat transfer - not really worth insulating behind the finned convectors but worth making sure there's good airflow over them.
 
Jun 16, 2020
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Heat is not lost from pipes within the van though some may be transferred. However. My Lunar, had the Alde heating pipe running behind the fridge. This is open to the atmosphere. So well worth insulating and easily done through the bottom fridge vent.

John
 
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JTQ

May 7, 2005
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By design the piping ought to be part of the overall intended heat transfer provision, therefore insulating them would be counterproductive in the functioning of the van's space heating system.
Are they not transferring heat internally, but not as effectively as the fined "convector" sections do to enhance more local transfer?
 
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Mar 14, 2005
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By design the piping ought to be part of the overall intended heat transfer provision, therefore insulating them would be counterproductive in the functioning of the van's space heating system.
Are they not transferring heat internally, but not as effectively as the fined "convector" sections do to enhance more local transfer?
That is correct, but knowing what I do know about the way caravan manufacturers look at heating packages, I seriously doubt they specify the system with the heat transfer from the pipework as a prime criteria.

However, this very fact was one of the key differences between wet and blown air systems that affects the way a caravan will heat up from cold.

It's also an important reason why wet systems can work better in bigger caravans and narrow boats as the heat can be transferred moved more effectively over longer distances.
 
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Jun 16, 2023
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Are they not transferring heat internally, but not as effectively as the fined "convector" sections do to enhance more local transfer?

I'd consider that heat convection as "lost in transit" because
* they mostly run in places without air circulation - effectively you are heating the surrounding buildings
* their surface area is very small, compare it to the total surface area of a radiator the difference is 3-4 orders of magnitude (1x vs 1000x), if not more
 

JTQ

May 7, 2005
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I'd consider that heat convection as "lost in transit" because
* they mostly run in places without air circulation - effectively you are heating the surrounding buildings
* their surface area is very small, compare it to the total surface area of a radiator the difference is 3-4 orders of magnitude (1x vs 1000x), if not more

We have vastly differing opinions on the" efficiencies" of these Alde convectors, bearing in mind the capacity per unit length is identical to the pipework used, as is the use of aluminium.
All my pipe runs are in deliberately vented spaces so the designer had addressed that point; however, I am quite sure on many counts UK van builders pay near zero attention to engineering design. I had very specifically used "ought", not even an expectation they would do things correctly.
That said if the pipework can't convect the heat away it is not an issue, just poorer heat distribution, plus any that "escapes" is not "wasted" if the pipework is within the space anyway. It just achieves better distribution.

If your stated difference is a 1000 plus fold, why are you worried about insulating for just less than 0.1% assumed "loss"? Not that I understand it is lost from the space.
 
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Mar 14, 2005
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I'd consider that heat convection as "lost in transit" because
* they mostly run in places without air circulation - effectively you are heating the surrounding buildings
* their surface area is very small, compare it to the total surface area of a radiator the difference is 3-4 orders of magnitude (1x vs 1000x), if not more
I'm not sure why your referring to "surrounding buildings" we are dealing with caravans not buildings. The laws of thermodynamics still do apply but the construction and thermal masses and insulation are very different in caravans compared to buildings.
 
Jun 16, 2023
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I'm not sure why your referring to "surrounding buildings"

Pardon my English, what I meant is the walls or any other structure in a close proximity to the pipe, surrounding it.
Heating walls is generally not a best way to heat a habitual space hence I would consider all the heat emitted there as a lost one
 
May 7, 2012
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+From what I have read on the subject the caravan makers do not design the system but send details of the caravan to ALDE who then deign the system for them. I am not sure to what extent pipe runs are considered but they do put heat into the body so there is no point in lagging them. I have not heard of anyone placing the reflective material behind the radiators, but if it works in houses it should work in caravans., possibly better as caravans have thinner walls.
 
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Pardon my English, what I meant is the walls or any other structure in a close proximity to the pipe, surrounding it.
Heating walls is generally not a best way to heat a habitual space hence I would consider all the heat emitted there as a lost one
In housing, heating the structure works very well. Known as heat capacity. Not quite as effectual in modern buildings, and less so in a caravan. But those who have used wet heating will tell you it takes longer to get warm initially from cold. This is because heat is being put into the structure. The upside is that when a door is opened, getting back to temperature is much faster. Warmth becomes more constant, less yo-yoing.

John
 
Nov 6, 2005
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+From what I have read on the subject the caravan makers do not design the system but send details of the caravan to ALDE who then deign the system for them.
Not true in the case of Lunar - that was very clear as Lunar involved an Alde engineer to resolve my poor performance issues which were down to the furniture preventing the recommended flow of air.
 
Mar 14, 2005
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Pardon my English, what I meant is the walls or any other structure in a close proximity to the pipe, surrounding it.
Heating walls is generally not a best way to heat a habitual space hence I would consider all the heat emitted there as a lost one
Unlike most domestic buildings (and I do mean buildings) where the thermal mass of the structure can soak up a lot of heat energy without raising its temperature, the construction of most caravans utilise a lot more insulation close to the surface, and as such the thin wood skin quickly starts to warm up compared to a conventional building, so the energy loss is not really lost it still appears as heat in the caravan,

+From what I have read on the subject the caravan makers do not design the system but send details of the caravan to ALDE who then deign the system for them. I am not sure to what extent pipe runs are considered but they do put heat into the body so there is no point in lagging them. I have not heard of anyone placing the reflective material behind the radiators, but if it works in houses it should work in caravans., possibly better as caravans have thinner walls.
The function of the additional insulation is to reduce the transfer of heat in the area where its used. bearing in mind the degree of insulation already in both the floor and wall any additional insulation on a wet heating pipe or behind the radiator is only going to make a small difference, Purely from a cost perspective the insulation will probably cost more than all the energy it might save.
 
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