Attempting to get my head around this ...........

[John M]

If I had 8mm pipes feeding a radiator, would that mean that I would need a larger radiator panel than if I fed with a 15mm pipes ?

Its just that while re jigging my supposed new system, the radiators look postage stamp sized, next to my footy field sized units

Mind you since the old system was engineered I have had DG & CWI installed

 

[chrishutt]

If I had 8mm pipes feeding a radiator, would that mean that I would need a larger radiator panel than if I fed with a 15mm pipes ?

No. The object is to have the same temperature drop across each radiator - e.g. incoming water 70°C, outgoing water 50°C, average radiator temperature 60°C. For most radiators 8mm pipe is just as capable of delivering the required flow as 15mm pipe.

 

[JohnD]

I like oversized rads, they can heat the house faster if you've been away, and they have capacity to cope with unusually cold weather. As everyone uses TRVs these days they do not use more heat once the house is up to temp.

There are some points about the efficiency of a boiler that works flat out to get them all hot, then sits back and has a rest for a while, but I don't understand how that works.

 

[John M]

I read somewhere that condensing boilers condense when heating up, but not when they have reached their allotted temp ...... Quite who & why I dunno.

If the trooth was out, in my household we only have two radiators on 95% of the timer allowed time, Lounge & hall ..... The rest of the place seems to keep fine & dandy without all the rads on ...... Well if all the rads are on the place is like the insides of a blast furnace ........... Thats without TRV's tho .......... A few years ago while having the lounge rad off I added a TRV, just to see if they were as sooper dooper as people were raging about ..... & I gotta admit that ya don't get the ...... Phwoar open the door fer ferks sake I'm a cookin' in here any more ..... Which is good

Tiz amazin what ya can do wiv tech these days