gas supply and flue termination
- Thread starter dyson20
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If you like the neighbours
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unless your having a whole new system or expecting to add to it, then you should size the boiler based on the output of your current radiators. As a very rough guide you can do number of rads X 1.5.
A fairly accurate way is total length of rad panels in metres (600 mm high, straight adjustment for different heights) = output in kW.
I agree with Mickey that doing a heatloss calculation is pretty pointless when the rads are already there.
I agree with Mickey that doing a heatloss calculation is pretty pointless when the rads are already there.
Mickey hit nail on the head. Whatever method you use, it will always be an approximation as the exact output given is only exact at the precise flow and return temperature used by the manufacturer. If memory serves, it is 75C in, 65C out and roomtemperature of 20C. In real life, this situation will only exist for a few minutes in a whole day, if that. One degree difference from the theoretical setup changes the output by 2 percent e.g. a rad that is listed for exactly 1 kW would be 40 watt off.
In winter you could have an average rad temperature of 75C and a room temperature of 10C when the heating starts, giving an "extra" output of well over 20%. At the same time, a lot of boilers are set at a much lower temperature which might only give 60C at the inlet of the rad, resulting in an average temperature difference with the room of only 40C, resulting in an output "loss" of around 20%.
And that is ignoring the millions of rads that are dirty inside, and thus not reaching the output even if the temperatures are exactly as designed.
In winter you could have an average rad temperature of 75C and a room temperature of 10C when the heating starts, giving an "extra" output of well over 20%. At the same time, a lot of boilers are set at a much lower temperature which might only give 60C at the inlet of the rad, resulting in an average temperature difference with the room of only 40C, resulting in an output "loss" of around 20%.
And that is ignoring the millions of rads that are dirty inside, and thus not reaching the output even if the temperatures are exactly as designed.
Slightly different angle!
I go to a lot of properties with very large sash windows. Many are in conservation areas where plastic double glazed windows are not permitted.
Even where they are, the sizes are often greater than the window manufacturers will make.
There is however a solution, thats is to add secondary glazing on the inside of the windows. Thats also permissable in conservation areas.
Tony
I go to a lot of properties with very large sash windows. Many are in conservation areas where plastic double glazed windows are not permitted.
Even where they are, the sizes are often greater than the window manufacturers will make.
There is however a solution, thats is to add secondary glazing on the inside of the windows. Thats also permissable in conservation areas.
Tony
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