differential temperatures

[jase1271]

could anyone describe to me the method of checking the differential temperatures of flowand return pipework given that the differential temperature is 11 degrees celcius??????,,,, thank you , i have looked everywhere and just cant see the method used , jase

 

[Agile]

The differential is not 11 °C.

Its whatever the settings of the system give. You measure it with a contact thermometer on each rad pipe.

Older non condensing boilers were designed for a flow of 82° and a differential of 11°.

Modern condensing boilers are more flexible but typically 70° flow and 20°-30° differential.

Tony

 

[jase1271]

thanks tony ,,,, it was for an assignment , and like a wrote i could not find it anywhere in the information they gave us to read ,,,, once again thanks
jase ,,

 

[baxpoti]

Differential temperatures should be measured at the boiler flow and return connections and measured from a cold start.

A condensing boiler would have an optimum differential of 20°C
Flow at 82°C and return at 62°C.

Maximum efficiency is obtained when the boiler is condensing.

A lower flow temp keeps the boiler in condensing mode for longer.
The optimum flow temp is 63°C.

 

[jase1271]

and thanks to you aswell baxpoti,