Hi All, be obliged if you could share thoughts on this...
I have a boatman stove with backboiler, running through 28mm copper convection pipes to produce hot water through calorifier in HW tank (have another engine fed calorifier that runs to same tank when cruising)
System runs well at the mo, gives me benefit of heat and HW without using any power.
I am considering fitting radiators to the back end of the boat, as the stove is at the front of the boat and heat doesnt make it to the back bedroom with space narrowed down by cupboards, bathroom etc, even with a fan sat on top of the stove.
In the past, someone has tried to extend the copper piping from the back of the stove to try and fit a convection ststem on it...there are Ts from the hot and cold return which run pipes for about a foot and are then blanked off, in effect the HW system runs from the back boiler down the port side,the exsisting system extention runs for a foot down the starboard side...
options are....
1) extend this system using 28mm copper convection by extending exsiting pipework down the S/board side into back bedroom
Issues with this... running 28mm through saloon and down entire cabin...I understand hot pipe needs a slight rise on it to work properly?...this would make radiator at bedroom end high on wall? also would want to run pipe under gunnel shelf so its out of sight and neat,so that would need to go up from the back boiler, run 30'feet then down 2' to the rad?
Would the system run two ways on gravity at once? and where can I source Rads with 28mm fitting for convection use?
2)Install 12 volt HW pump at back boiler end, reduce exsisitng 28mm down to 15mm, use speedfit palstic pipe to ordinary rads down starboard side, leave exsisitng HW convection in place, but connected up to this system.
Issues...
Running 12v pump on this sysem may cause it to back up on Cold return at back of stove(cold return still gravity fed)
System wouldnt heat up quickly enough with water circulating?
Might be bloody dangerous!
3) Make new loop/extension where 28mm convection return pipe runs out of cal...fit 12v pump and run 15mm speedfit from there down to rads in Bedroom and return to join cold return
Issues...
System wouldnt run normal convection as I am breaking into the pipe to fit pump, so would always require power to drive water round..even if I only want HW? Dont have access to shore power so concerned about power use...
Options...
option 1 low tech solution...but clumsy/messy
Option 2 dont think would work, may block up
Fit option 3 and always have concerns over power
Forget about it and wear a hat in bed...
all suggestions gratefully received..
El G