GTM_88

I've read that afew times man and I'm trying to picture the logic but struggling abit, does warm air from the cabin have to reach the side of the fuel tank for that to happen? does it make any difference the boat is trad stern and my fuel tank is right at the back integral to the hull/stern. There's a bulkhead between the engine bay and cabin with the door shut basically all the time, the stern area is bloody freezing compared to the rest of the boat and all still bare metal, but very dry I've never seen any condensation on the end where the fuel tank is... does that make any difference? I haven't ran the engine for a hell of along time, basically just to move it once and mess about with the electrics afew times during the summer. It hasn't moved off it's mooring since I've been fitting it out. Now you mention this however... I did get diesel bug in my generator fuel tank and I drained the tank, refilled and put some treatment in. There is a water separator on the engine yes.

Get it so hot in there your sat with the door wide open when there's snow on the ground? 😂 Was that in an older boat with sheet insulation spaced from the hull or was it more recent and insulated differently? Ah man the bloody ducks scared the living crap out of me doing that at 2am! not long after I first got the boat 😐😆 I had no idea what it was 😐 😂😂😂 my mooring is very out the way in fields, pitch black and noone around. I sat there petrified for 10mins before working up the guts to stick my head outside and look what it was tapping on the side of the boat! 🤦 And there's this duck looking back at me 😂

We literally call it "the mobile corridor" 😆 the thermal store started as a 180 litre copper vented cylinder with twin indirect coils, it was brand new but sold very cheap so I snapped it up. I've brazed in three direct tappings, two 3/4" for the woodburner, one at the bottom and the other roughly two thirds up, and the other is a 1" that sits more or less in the middle. The woodburner will plumb direct, the 1" connection takes a DC water heating element (for solar load diversion) the first indirect coil will be a Eberspacher D5WSC, second coil will be linked to the boat engine and there's a mains immersion element in the top. I've had a stainless header tank fabricated for it thats sealed from the inside of the boat but has a 1.5" vent to outside on the roof, also an overflow. The secondary hot water comes from a plate heat exchanger and the heating will also be sealed from another plate heat exchanger. The main reason for the thermal store was the woodburner needed to be open vented but I wanted a sealed pressurised heating loop and also it gets around crap hot water pressure like with a header tank setup. I have seen alot of boats with copper cylinders with a PRV banged on top instead of the open vent 😂 slightly amusing, like an poor attempt at an unvented cylinder 😂 by heck you'd not be popular if you did that in a house.... I did wonder about having polycarbonate circles cut for the portholes to increase security, the boat is all portholes. Power wise I've got two 48v 280ah lithium batteries, 2250watts of solar, victron mppt and victron Multiplus2 48/8000/110 inverter charger, and I've fiddled with the beta marine 175amp alternator, it works in AC to start with and is wired to external rectifiers with a cap which then goes through another MPPT solar controller to charge the 48v batteries from the engine. There's also a 6KVA diesel generator fitted to the right of the boat engine that I've been running on veg oil with a separate tank. What I really want to do is automate the generator through the Multiplus2, I have managed to build an Arduino that starts the diesel generator but it needs way more fiddling. I very briefly looked at electric drive but I really wanted to own a mechanical beta marine engine because I love mechanical diesels. I have since seen hybrid setups where it's both diesel and electric, it would be fun to try and pull that off. I'm based in Leicestershire.

Noted, good advice. There is mushroom vents in the roof (well, the holes are there) but their sealed at the moment because whoever fitted them made a terrible job of drilling the holes for them. I was on the fence about refitting them but I'll reinstall them, I hadn't thought of C02 build up. Don't have to apologise for sounding blunt John, cracking advice. I think part of BSS (boat safety) stipulates their has to be ventilation but I'm nowhere near the stage yet of thinking about it. It's very much a semi building site at the moment.

Very much so, the trouble is I've foiled the entire boat effectively sealing it, it's basically air tight, so Inturn moisture can't escape, I have a meaco 25L dehumidifier which runs from a 48v battery bank. I was looking at installing a MVHR but I decided I couldn't be bothered with the amount of work adding even more time. I'm hoping it's less of an issue in regards to condensation/mould though, because I don't have any surfaces inside that are cold enough for moisture to condense onto, every metal surface is insulated with spray foam insulation with foil insulation over it. in theory moisture in the air can't cool and create excessive moisture build up. Its taken ages to DIY apply three rounds of spray foam insulation messing around with a spray foam insulation kit and heated blankets to warm the bottles. The thinest being about 45mm and I think the walls have ended up being roughly 70mm and it has double glazed windows. It does make a huge difference though when inside is very very warm and you leave a window open, the rising warm air pulls alot of moisture with it. This was another thing that got me onto underfloor heating though was the hope it irons out the rises and falls in temperature and (fingers crossed) means the internal temperature doesn't drop like a brick at times. I've not got gas onboard either so I'm not putting moisture into the air using a gas hob.

Fingers crossed, I'm hoping I've done enough it won't be a disaster. I've managed to seal the air gap by tucking a layer of 25mm insulation under the edge of the spray foam (where the wall meets the floor) and then a layer of radiant foil, which has a 20mm-ish air gap Infront, then the 18mm plywood subfloor with a layer of 60mm PIR insulation on top. I'm hoping the foil layer with the air gap Infront is going to help. There is ventilation through the bilge (the space under the 25mm) at a different part of the boat. So the second layer, that's 60mm sort of floats almost. Any downward heat loss that comes through the layer of 60mm then has to cross the air gap and make it through the radiant barrier.

A warm hello Alot of my searching and reverse engineering for answers often brings me here, I've noticed alot of ideas get debated here, many other sources of information only entertain doing things "the done way" I red a fantastic post on here recently about using an indirect coil on a cylinder to heat an UFH loop, and the answers provided were very constructive and interesting. There was very good insight not just "no, thats a terrible idea" which makes a very refreshing change. I have to admit, I am abit of an imposter, I am not in a bricks and mortar property, but a liveaboard 60ft narrow boat. Alot of the boat is being built with the same knowledge applied, at least towards insulation, heating and electrics. Very recently I have reverse engineered the basic principle of a thermal store, and installed one into the boat. I will try to help others aswel where I can, I have previous employment in Paint spraying and Plumbing, unfortunately the latter tends to only be common domestic and maintenance areas, rather than all out heating engineering (annoyingly) I've had to self teach myself that having left the occupation sometime ago. I have registered because I am abit stuck when it comes to choosing my wet underfloor heating method and hoping to find some answers or ideas, back when I did my plumbing apprenticeship, underfloor heating was extremely rare. It does exist on boats, but so far I've only found one mentioned, it was apparently very successful so it seems achievable, but I need to get my head around some basic principles first, and the knowledge is obviously fluently applied to houses. Thanks for reading and look forward to contributing