I am the most humorous and funniest person in the world.
I am the most humorous and funniest person in the world.
Yeah, right.
They're not laughing *with* you, you know.
Thank You.
IMM burbled fatuously:
And you always tell the truth as well.
My my!
In message , IMM writes
Still not got the hang of grammar though have you
I am also the most honest person in the world too.
I am the most literate person in the world.
Now its fairly obvious how to easily calculate the size of the world that IMM lives in. Bringing a whole new slant to the catchphrase 'its a small world innit?'
How big is Mars, now have had a stroll around it?
(with a bit of cut and paste)
In message , IMM writes
But not in the real one which the rest of us inhabit
Maxie, I don't go to Mars.
In article , Andy Hall writes
On the eco-hometec web site they claim that the maximum a 15mm pipe can carry is 9Kw - but we don't know if a condensing boiler is fitted. If not then the same web page states 4.25 Kw maximum at 1.5m/s flow.
In message , IMM writes
So why did you start going on about it?
The suggestion of 9kW is not directly as a result of having a condensing boiler but because it *may* be possible to design the system around 70 degree flow and 50 degree return temperatures. However, for this to be possible, the radiators have to be derated to a factor of 60% of the data sheet value as opposed to the 89% or so for a conventional 82/70 degree system. That is not to say that a condensing boiler won't work if it is directly replacing an older 82/70 degree boiler. Typically it will increase its flow temperature accordingly when required to cover worst case weather conditions. However, the temperature drop may not be as much as 20 degrees any more and hence the heat transmission through the pipes is less. Heat output from the radiators is increased in this scenario because the mean water to air temperature is higher. Some condensing boilers can have their operating temperature limits set for different applications. For example on mine, I can set for
55, 70 or 85 degree maximum flow temperatures for UFH, condensing design or conventional design heat emitters.The 6kW figure is given as a starting point in HVAC design guides as well as white papers on the Copper Development Association web site using a few metres of pipe. The CDA design guide then suggests, as I have done, to do the sums if the load is close to this figure. I tend to do the calculations as a matter of course if I am putting on radiators of capacity more than about a third of the rule of thumb number. It is a simple matter of looking up the numbers in tables and some addition and multiplication.
.andy
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Has somebody just farted.
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