How much kilowatts of heat will 15mm/22mm/28mm copper pipe usually transmit ok? I imagine it can differ with different flow temperatures. Just wondered were I could find ball park figures? Thanks
Kilowatts of heat per pipe size
- Thread starter Fredstudio
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I know the larger pipes are a problem as it takes the water too long to reach taps, and they clearly radiate heat, as water in pipes soon cools down, however I am sure lagging would help, reducing the heat radiated from the pipes.
There are online calculators,
I have used them to see how much power to heat my DHW tank, but in real life it does not work, as my immersion heater only heats the first 9" of water, so today exported 25 kWh to the grid.
To transfer heat using water, flow rate clearly matters, and also the pipe diameter, but also the temperature difference, and temperature of water also depends on pressure, the water circulating in our power stations can be 400ºC due to the pressure, which in turn boils water making super heated steam. Not that we would do that in the home, but you have not said where the pipes are.
In my old home, we had a very small fan assisted radiator, 12 mm pipes fed it, the output was around 4 kW, the pipes near enough cold when fan running at full speed on the return. Over twice the size double radiator, again 12 mm pipes, but the return water temperature was a lot hotter.
There are online calculators,
I have used them to see how much power to heat my DHW tank, but in real life it does not work, as my immersion heater only heats the first 9" of water, so today exported 25 kWh to the grid.To transfer heat using water, flow rate clearly matters, and also the pipe diameter, but also the temperature difference, and temperature of water also depends on pressure, the water circulating in our power stations can be 400ºC due to the pressure, which in turn boils water making super heated steam. Not that we would do that in the home, but you have not said where the pipes are.
In my old home, we had a very small fan assisted radiator, 12 mm pipes fed it, the output was around 4 kW, the pipes near enough cold when fan running at full speed on the return. Over twice the size double radiator, again 12 mm pipes, but the return water temperature was a lot hotter.
At a typical velocity 1 m/s, and temperature drop 10K, for a 22mm pipe I make it 13kW as a ballpark.