Super insulated Calorifier

[Ex- Member]

I meant to post this last year when I had finished but forgot. I'll add now though as it's part of our build and might be of interest.

 

 

Super insulating our calorifier

 

Original fitment.

 

 

On our return to refitting the boat last year following a long break in the fitting out process we came across a few problems.

One was the ceramics in the shower had cracked and weren't replacable so we had to fit a new shower, another was a spit in a

reducing joint in the central heating system which was caused probably by freezing, what with the boat being left unattended.

The heating system wasn't full so had no antifreeze additive but we think some water was in the system and trapped in this joint

that split as it was low down.

 

Anyway after a couple of weekends all these problems were put right, then we noticed the water pump coming on

periodically when no water was being used, we eventually found a leak in the verticle calorifier in the joint where the engine hot water

enters the calorifier's heating coil so yet another thing to put right. On inspecting this leak I wasn't sure weather the joint above wasn't

leaking either so I decided to remove the calorifier and bring it back we me to Dorset so I could repair all the joints and pressure test it in

the comfort of our warehouse. It did turned out both joints had been leaking.

 

Whilst disconnecting the brass connections some insulation was lost around the 4 vertical joints and there was a pretty large crack in the

lower part of the insulation from the centre of the calorifier to the base . I refitted all the joints with new fibre washers and some gunky stuff

our local heating engineer suggested we use. Had it pressure tested and all ok.

 

The lost insulation and the crack in it was niggling me and on further inspection realised that in places the insulation thickness was barely an inch

anyway so after some thought I decided it wasn't good enough and decided to double insulate it.

 

I cut a disc out of 18mm ply wood 40mm wider than the overal diameter of the calorifier, this gave me a 20mm ply overlap all the way

around the unit.

 

The disc on top had to have another large hole drilled in it to eccept the heating element section on top. The very base of the calorifier

was partially hollow at it's base, so i cut another disc of plywood that fitted snugly inside the copper rim at the base, after filling the void

with insulation, I then applied some good quality sealant spread all the way around the ply edge and then screwed the copper edge into

the edge of the inserted ply , this now gave me a good solid fixing for the bottom outer disc to fit to.

 

This was cut into a circle with a 45mm overlap all the way around the base.

 

I then cut 8 x 50mm x 25mm battons to the same length which i then fitted equally all the way around the outer edge of the top ring of ply

and then butted the batons to the bottom ply disc and screwed up into the long grain from the bottom ring of ply keeping the front face

edge of the baton flush with the face edge of the ply ring. The lengths of baton were measured so the top ring of ply was raised an inch

above the existing insulation. I then lined and squared it all up and secured it with blobs of sprayfoam squirted periodically around the casing

creating a uniform cylindrical skeleton.

 

When dried I had a nice rigid frame which would give me an extral 45mm or over 1.5 inches of additional foam insulation over doubling the

existing applicaqtion.

 

I then covered the carcase with some 3mm flexible White Polypropelene sheet which I pre cut to size which wrapped around the frame a treat

creating a nice solid cylindar. Polypropelene in it's self also has insulating properties so a good choice for the casing, looks good and brilliant stuff

to work with being easily cut with a stanley knife and flexible.

 

I left the vertical section with the renewed joints still exposed but situated some baton on either side of these joints which the polypropelene

edges were finally screwed to. This created a cavety around the existing spray foam of around 40 to 45mm or 1.5 inch this was then filled with fire

proof sprayfoam insulation all around the calorifier. I masked off the top heating element with some large plastic pipe so not to clog it with foam.

The small drain plug was also masked with some plastic pipe to ensure it's future accessability.

 

For the front vertical section left open containing the main joints I masked over and filled with more spray foam.

a raised box cover that slots and screws on to the baton surrounding it is currently being finished.

so when the calorifier is fitted into the boat and the pipewrok connected, the boxed area has an additional sheet of 2 inch foam cut to fit around

the joints.

 

The same applies with the element on top of the calorifier using a round plastic top cover and some more foam.

so now all the joints on the calorifier can be accessable and can be inspected and replaced if necessary.

The extended box section will also cover most of the exiting pipework so further insulating.

 

It's now all fitted in and working, I just need to further insulate the remaining hot water white pipework and finish the cover.

 

The larger ply base also created a much better fixing to the engine room boxed floor than before. So the whole thing is a lot more sturdy.

 

We tested it overnight after bringing it up to full temperature, then switching off at midnight. On testing in the morning around 9am and we were

very pleasantly surprised, the temperature of the water was dramatically hotter than ever before . Prior to this it was bearly luke warm over 8 to 9

hours but since it has been overhauled it's definitely much hotter and still warm after lunch if not used for a shower. A tank Jacket would probably

have been much cheaper alternative although, saying that the main cost was the poly sheet around 20 quid the rest of the materials used were

offcuts lying around and the spray foam I had left over from fitting the porthole liners.

 

I also got hold of some brand new original SS Jubilee clips from good ole E-bay, just brilliant quality compared to the rubbish you can get

today wrapped on original Brown grease proof paper and covered with sticky oil. managed to get enough to replace every Jubilee clip

on the boat and some spare.

 

 

 

Overall though I'm very happy with the result and quite pleased at how it looks also.

 

 

Edited July 9, 2011 by Julynian

[blackrose]

We tested it overnight after bringing it up to full temperature, then switching off at midnight. On testing in the morning around 9am and we were very pleasantly surprised, the temperature of the water was dramatically hotter than ever before. Prior to this it was bearly luke warm over 8 to 9 hours but since it has been overhauled it's definitely much hotter and still warm after lunch if not used for a shower. A tank Jacket would probably have been much cheaper alternative although, saying that the main cost was the poly sheet around 20 quid the rest of the materials used were offcuts lying around and the spray foam I had left over from fitting the porthole liners.

 

I'm surprised that your calorifier wasn't even keeping the water hot for 8 - 9 hours. I just have a standard calorifier but it keeps the water hot for at least 24 hours. It starts to become warm after about 36 hours. Are you sure you don't have an issue of hot water convection to your engine?

Edited July 16, 2011 by blackrose

[Ex- Member]

I'm surprised that your calorifier wasn't even keeping the water hot for 8 - 9 hours. I just have a standard calorifier but it keeps the water hot for at least 24 hours. It starts to become warm after about 36 hours. Are you sure you don't have an issue of hot water convection to your engine?

 

Quite possibly I need to fit a non return valve on the engine hoses or even both I'm not sure. One of those things I keep meaning to do but we're on shore line so keep forgetting LOL

 

I'll get on this though as I would like to do a proper test as to how efficient it might or might not be.

 

Any advice on what return valve to use would be helpful, Cheers!

 

 

 

[dor]

Any advice on what return valve to use would be helpful, Cheers!

 

You need to use a flap valve - you can get them from Aquafax - a 1/2" one. Make sure you fit it horizontally with the hinge at the top. The advantage of a flap valve is it gives virtually no resistance to the flow from the engine - spring non-return valves can significantly restrict flow.

 

The alternative is to make a big loop in the engin e to calorifier pipe to stop thermo-syphoning, although I perfer the flap valve if the base of the calorifier is lower than the engine - i.e. floor mounted. Horizontal calorifiers on the swim shouldn't have a problem but are more prone to thermosyphon loss if on the floor.

[Ex- Member]

You need to use a flap valve - you can get them from Aquafax - a 1/2" one. Make sure you fit it horizontally with the hinge at the top. The advantage of a flap valve is it gives virtually no resistance to the flow from the engine - spring non-return valves can significantly restrict flow.

 

The alternative is to make a big loop in the engin e to calorifier pipe to stop thermo-syphoning, although I perfer the flap valve if the base of the calorifier is lower than the engine - i.e. floor mounted. Horizontal calorifiers on the swim shouldn't have a problem but are more prone to thermosyphon loss if on the floor.

 

Thanks for that Dor I do now recall my brother telling me the same some time ago.

 

Just put flap valve into google but seem to get large engineering flood prevention stuff, and brand name you know of for a flap valve?

 

Sorry got it Aquafax

 

 

 

Edited July 16, 2011 by Julynian