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By defcribed
#1894063
@Colonel Panic I would avoid anything fancy or 'designer'. Traditional radiators are the way they are because that's basically the most efficient way to do it. The claimed output of designer radiators will be based on a flow rate that you'll never achieve and a very high flow temperature.

@rikur_ true, it isn't all bad news. I am now happy with my system except for the fact that the pump is working very hard and I'm concerned it'll fail prematurely. @Flyin'Dutch' it shouldn't clog up as long as it isn't left without inhibitor for any length of time. If it is pumped hard (as it usually needs to be) there are arguments that it is actually less susceptible to clogging than 15mm because of the higher water velocity.
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By OCB
#1894083
Can I, as an auld phart with a tiny bit of professional skin (and a lifelong passion for the tech) in this fight just say that:

“Efficiency is king”

Watts in, watts out - sounds a bit “karate kid”, but I’m the worst kind of fundamentalist- the one that expects author and validated quotations.
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By defcribed
#1894166
OCB wrote:Can I, as an auld phart with a tiny bit of professional skin (and a lifelong passion for the tech) in this fight just say that:

“Efficiency is king”

Watts in, watts out - sounds a bit “karate kid”, but I’m the worst kind of fundamentalist- the one that expects author and validated quotations.


Just so long as you are actually getting the watts out over a sustained period of time, rather than the water in the system going hot cold hot cold hot cold as the boiler short-cycles.

The main issue these days is that boilers are specced for incredibly high instant hot water demand (e.g. two pumped showers running at once and still expecting hot water from the kitchen tap) so are completely over-sized for the heating system. They often can't modulate their output down far enough to burn continuously for a sustained period, as they need to when e.g. coming on at 6am and trying to heat the house from 16 degrees to 20 degrees. They certainly can't run with a flow temperature low enough to get them condensing. So they switch on, the flow temperature rockets up to 80+ and they cut out for a few minutes before trying again, repeat ad nauseum.
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By OCB
#1894489
defcribed wrote:
OCB wrote:“Efficiency is king”


Just so long as you are actually getting the watts out over a sustained period of time, rather than the water in the system going hot cold hot cold hot cold as the boiler short-cycles.

The main issue these days is that boilers are specced for incredibly high instant hot water demand (e.g. two pumped showers running at once and still expecting hot water from the kitchen tap) so are completely over-sized for the heating system. They often can't modulate their output down far enough to burn continuously for a sustained period, as they need to when e.g. coming on at 6am and trying to heat the house from 16 degrees to 20 degrees. They certainly can't run with a flow temperature low enough to get them condensing. So they switch on, the flow temperature rockets up to 80+ and they cut out for a few minutes before trying again, repeat ad nauseum.


:thumleft:

Yep - absolutely, definitely! Although, let’s not let older systems off the hook either, eh?

rewind nearly 35 years ago, my first company was trying to convince industrial and large residential owners to swap out their extremely dumb controllers for a controller system that kept their output much closer to the possible efficiency curves. Sizing of boilers was never ideal, and many weren’t condensing etc.

Energy was far too cheap back then, even when I guaranteed a payback period of 2 years - what seemed like a “no brainier” to me was a simple “no” to most.

Result - I gave up. Company didn’t actually make a loss, but it was a commercial failure.

Interesting to read that folks still understand the fundamentals though :)