Solid fuel CH circuit.

[Tomo2]

Hi, I have fitted a rayburn and I'm going to run just 2 radiators from it. (double convector 2kw and 1kw ) It will not be doing DHW so no water tank in the circuit.

The rayburn and the the radiators are all on the ground floor but the first run of pipe work has to go straight up stairs then drop back down to the radiators from the main circuit. the main run of the circuit (flow, return loop in 22mm) up stairs is approx' 12m. Not including spurs/drops to the rads.

The pipe work going directly from the rayburn (flow and return) for the first 3m is 28mm reducing down to 22mm which is to/from header tank and vent plus making the circuit, can I drop down staright from the circuit to the radiators using 16mm (this is in France, no 15mm) or do I need to drop down in 22mm then 16 to the rads?

Secondly, is this going to cause any problems with flow, air locks etc and do I need a heat sink rad upstairs?

It was going to be gravity fed but obviously with the rads being down at the same level and the pipe work going straight up this will not work so well, I do have a pump to put into the circuit.

Thanks for any advice offered.

 

[Nige F]

as much as poss. in 28 - then drops in 22 - and I`d like to see 22 connections to the rads if at all possible to get them that size now . Yes have an upstairs heat sink with no valves on it . I`m thinking a gravity circuit with pump assistance - I`ve seen a Solid Fuel rayburn out of control But then I`m just an old fart from the sticks with no Hetas certificate. Is it possible , in France to get a metal header tank ? I could maybe need one over here later

 

[Tomo2]

Thanks for that Nige, unfortunately the main circuit is already in 22mm but I haven't put the spurs in yet so they can be in 22 now, although I will have to reduce down to 16 to connect to the rads as the fitting options are not that good here.

As for the heat sink I will do that now, but I was trying to avoid this because 'upstairs' is just basically open loft with outside ambient temps', so what are your thoughts about using a small single 600x600 rad as the heat sink?

Many thanks for your prompt reply.

 

[dcawkwell]

If you have drops from upstairs it won't work on gravity unless you are pumping the whole thing.
There is no point in having 28mm if you are pumping, 22mm will be fine.

 

[DeltaT2]

With gravity circulation like you intend to do; single pipe drop feed is best, but your Return must be on the Ground Floor only, you can do it with a raised return, but your Flow would need to climb to the apex of your house!!!

I'd love to see half the chancers on here trying to design a single pipe drop feed gravity system................

 

[Nige F]

I`m snookered because I could draw you a thermo syphon circuit on the back of a fag packet - but haven`t a clue how to get it , or any line drawing onto a computer . One important thing though - is the boiler a cast iron one ? If it`s welded steel then it`s another ball game because if the thing gets a return temp. too cold it`ll rot out eventually . The Rayburn I`m familiar with has a lump of iron for a boiler .

 

[DeltaT2]

I`m snookered because I could draw you a thermo syphon circuit on the back of a fag packet - but haven`t a clue how to get it , or any line drawing onto a computer . One important thing though - is the boiler a cast iron one ? If it`s welded steel then it`s another ball game because if the thing gets a return temp. too cold it`ll rot out eventually . The Rayburn I`m familiar with has a lump of iron for a boiler .

If you're only charging 100 sheets a shift mate, it's no surprise you can't afford a scanner or Autocad!!!...............