Copper Pipe - 15mm vs 10mm Microbore

[vonsworld]

Hello

We have recently had a new central heating system installing with a gas condensing boiler.

The fitter has used a mixture of 15mm and microbore copper piping. The 15mm takes the main runs from the boiler to each floor, and then from there he switches to microbore to supply each radiator.

Are there any pros and cons to this approach please and is performance effected compared to using all 15mm piping?

I must say the microbore doesn't look as good when it runs to the radiators, since none of the pipes look exactly straight. I also presume that using microbore would save some money on copper and with less joins make the fitting quicker?

Thanks

 

[LetSearch]

yes, it's a cost issue, using microbore is a budget option.

at least he's used 10mm, some installers use 8mm, which is much worse.


yes, it's a performance issue, but 10mm ci=overs quite lot.

I'd be more worried about the 15mm main runs, these should be 22mm.



Here's a link to my thoughts on central heating pipe sizing

 

[D_Hailsham]

It all depends on how much heat is being carried through the pipes and the flow rate.

If it's a new system designed with condensing in mind (20°C differential) the capacities are:

15mm - 3.6 - 12kW (max 18kW)
10mm - 1.45 - 4.8kW (max 7.3kW)
8mm - 0.9 - 3kW (max 4.5kW)

This based on a flow rate of 0.3 to 1m/sec (max 1.5m/s)

If the flow rate is too low there is a danger of sludge settling in the pipes; if it's too high the flow will be audible.

 

[dcawkwell]

Hello

We have recently had a new central heating system installing with a gas condensing boiler.

The fitter has used a mixture of 15mm and microbore copper piping. The 15mm takes the main runs from the boiler to each floor, and then from there he switches to microbore to supply each radiator.

Are there any pros and cons to this approach please and is performance effected compared to using all 15mm piping?

I must say the microbore doesn't look as good when it runs to the radiators, since none of the pipes look exactly straight. I also presume that using microbore would save some money on copper and with less joins make the fitting quicker?

Thanks

You have had the cheap skate install.

Best is 22mm flow and returns pipe branching to 15mm pipes to the radiators. Your system will take longer to heat up and may possibly be more likely to block up in the future.

 

[compheat]

Hello

We have recently had a new central heating system installing with a gas condensing boiler.

The fitter has used a mixture of 15mm and microbore copper piping. The 15mm takes the main runs from the boiler to each floor, and then from there he switches to microbore to supply each radiator.

Are there any pros and cons to this approach please and is performance effected compared to using all 15mm piping?

I must say the microbore doesn't look as good when it runs to the radiators, since none of the pipes look exactly straight. I also presume that using microbore would save some money on copper and with less joins make the fitting quicker?

Thanks

You have had the cheap skate install.

Best is 22mm flow and returns pipe branching to 15mm pipes to the radiators. Your system will take longer to heat up and may possibly be more likely to block up in the future.

Why will it take longer to heat up, it all depends on the output of the rads.
22mm should be used from the boiler but how much depends on the plumber and without seeing the install its hard to say one way or the other

 

[dcawkwell]

Hello

We have recently had a new central heating system installing with a gas condensing boiler.

The fitter has used a mixture of 15mm and microbore copper piping. The 15mm takes the main runs from the boiler to each floor, and then from there he switches to microbore to supply each radiator.

Are there any pros and cons to this approach please and is performance effected compared to using all 15mm piping?

I must say the microbore doesn't look as good when it runs to the radiators, since none of the pipes look exactly straight. I also presume that using microbore would save some money on copper and with less joins make the fitting quicker?

Thanks

You have had the cheap skate install.

Best is 22mm flow and returns pipe branching to 15mm pipes to the radiators. Your system will take longer to heat up and may possibly be more likely to block up in the future.

Why will it take longer to heat up, it all depends on the output of the rads.
22mm should be used from the boiler but how much depends on the plumber and without seeing the install its hard to say one way or the other

Been to a place recently with nasty 10mm piping. Same 30kw boiler I have installed in numerous places. Boiler cycled as it could not get rid of the heat fast enough as it would have done with 22mm and 15mm. Customer had a couple of fancy corner radiators quite large water volume. The supply to them from the 10mm was barely enough to get them warm. A "normal" system with 22mm and 15mm they would have been scortching hot in no time. 10mm also seems quite hard to balance the system up well.