MrTrevithick Posted December 9, 2020 Share Posted December 9, 2020 After a bit of advice here regarding best radiator feed system to install on my system. Let me explain (sitting comfortably then I’ll begin), my system is completely off grid but I don’t like being cold and I have a reasonable size property to heat (about the size of a 3 bed bungalow with very good thermal mass and insulation). I have original cast iron radiators around the place of which there will be about 9 maybe 10 in total, the system doesn’t have to react quickly due to the thermal mass but it does have to disperse the heat from the Rayburn (solid fuel) as it has a high capacity boiler and can heat the thermal store (300ltr) rather quickly. The Rayburn is feeding the thermal store via a gravity feed system (all on a single floor but it works well). I’ve installed a flow and return from the thermal store (pumped) but have only just got out into the main property so I was wondering what system of pipe work to install ? The place is rather solidly built and I’d rather not drill holes I don’t have to. The main pipe work is 28mm copper surface mounted with brass mountings (not that that makes a lot of difference) so I was also wondering at what length do you start to think about expansion loops or the modern equivalent? Cheers. Link to comment Share on other sites More sharing options...
PeterW Posted December 9, 2020 Share Posted December 9, 2020 Can you draw a rough plan ...? How far from Rayburn to thermal store for example ...?? TBH if you want to just warm the place, a single pipe running from rad to rad would be fine as it will be easy to install. If you want the ability to isolate rads then you’re better running a pair of pipes for flow and return. Thermal store shouldn’t need expansion as it’s either built in or the expansion tank should be above it (or it’s just become a very dangerous sealed unvented cylinder ..!!) Link to comment Share on other sites More sharing options...
Onoff Posted December 9, 2020 Share Posted December 9, 2020 Crazy thoughts maybe but what's the floor make up? Any insulation under that? High ceilings? Over height doorways? Would UFH be an option with say 150mm PIR then 100mm concrete/screed? Link to comment Share on other sites More sharing options...
SteamyTea Posted December 10, 2020 Share Posted December 10, 2020 9 hours ago, MrTrevithick said: about the size of a 3 bed bungalow How about some actual figures: floor area, wall area, perimeter to area fraction, volume. 9 hours ago, MrTrevithick said: very good thermal mass Oh dear, where do we start with this one. It is probably having a greater cooling effect, especially as some of your place is buried. 9 hours ago, MrTrevithick said: insulation Where is it: inside, outside. Cold bridging? 9 hours ago, Onoff said: Crazy thoughts maybe but what's the floor make up? Any insulation under that? High ceilings? Over height doorways? Would UFH be an option with say 150mm PIR then 100mm concrete/screed? Not that crazy, fitting far-infrared on the ceiling would be crazy. But sticking with that theme, how about forced air heating, get the air changes then. But hard to fit with thick walls, and takes power to run. How do you generate power to run the pumps at the moment? Link to comment Share on other sites More sharing options...
Onoff Posted December 10, 2020 Share Posted December 10, 2020 5 minutes ago, SteamyTea said: Where is it: inside, outside. Cold bridging? Is he thinking the mass of earth surrounding the bunker? Link to comment Share on other sites More sharing options...
SteamyTea Posted December 10, 2020 Share Posted December 10, 2020 (edited) 8 minutes ago, Onoff said: Is he thinking the mass of earth surrounding the bunker? Who knows, The Lizard is a bit insular, or is it Peninsular. Considering that Goonhilly was a communication centre, then got taken over by BT, you would think that a mobile phone would work, but no, all the white vans drive to Culdrose, pull over in a layby, and check for messages. I like it down there. Daphne de Maurier wrote The Birds, after a childhood experience with seagulls, down there. Edited December 10, 2020 by SteamyTea Link to comment Share on other sites More sharing options...
Onoff Posted December 10, 2020 Share Posted December 10, 2020 21 minutes ago, SteamyTea said: Daphne de Maurier wrote The Birds, after a childhood experience with seagulls, down there. I heard she wrote it after seeing the Hitchcock film. Link to comment Share on other sites More sharing options...
SteamyTea Posted December 10, 2020 Share Posted December 10, 2020 2 minutes ago, Onoff said: I heard she wrote it after seeing the Hitchcock film. Time Travel was it. The film came out 9 years later. Link to comment Share on other sites More sharing options...
MrTrevithick Posted December 10, 2020 Author Share Posted December 10, 2020 2 hours ago, Onoff said: Is he thinking the mass of earth surrounding the bunker? Ah, the thermal mass is the concrete (18” thick walls and roof and 4‘-5’ thick in the floors) the whole place is then clad in 1”-2” thick bitumen cement and buried so the earth/aggregate thickness is between 6’-20’ thick. I have blown air heaters feeding through the original cable ducting about 3’ under the floor which keeps things ticking over at 18 dec C (a system used by the MOS when building underground factories) but I would like a second option to heat hence the radiators. The original system (now out of commission) was a 9kw blown air system at ceiling height and the original radar equipment in the place would have produced a lot of heat (it had a HV substation to feed it all due to power distribution distances). The walls and floor hold a steady temperature. I can’t line out the building as it will destroy the original features but it was designed to hold sensitive equipment so it is very dry (bit too dry tbh). I was thinking along the lines of a flow and return pipe and tap off to the rads so I maybe going the right way. On the plan the Rayburn is by the dotted square in the filtration room and the thermal store is in the room below, I’ll get my measuring stick out but the big receiver room is 7 mtr by 5.8 mtr to give you an idea of scale. Link to comment Share on other sites More sharing options...
MrTrevithick Posted December 10, 2020 Author Share Posted December 10, 2020 Oh ceiling height is 8’ except the small receiver room which is 10’. Link to comment Share on other sites More sharing options...
MrTrevithick Posted December 10, 2020 Author Share Posted December 10, 2020 Pump power is from the solar system, that’s another subject. Link to comment Share on other sites More sharing options...
MrTrevithick Posted December 10, 2020 Author Share Posted December 10, 2020 18 hours ago, PeterW said: Thermal store shouldn’t need expansion as it’s either built in or the expansion tank should be above it (or it’s just become a very dangerous sealed unvented cylinder ..!!) The TS has an expansion tank via the loop from the Rayburn (it has a bleeder just for the top of the TS as well), after a bit of experimentation and advice from a couple of aged plumbers the gravity loop system came about. The problem was that the TS and Rayburn were on the same level so how to make a gravity feed work? But the solution works fine but I had to mount the expansion/header tank a lot higher than the system, which it is. I’m just in the process of building a control panel to run the central heating and include the fail safes but the gravity feed system takes care of itself rather well. I’ve done the unvented system course and work on heating and ventilation systems in supermarkets etc so am aware of the dangers of unvented hence I went down the vented TS route, plus it works well with the off grid nature of the place. 1 Link to comment Share on other sites More sharing options...
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