1 pipe or 2 pipe system

[steveb1964]

hi

is there an easy way to tell if ur heating system is 1 pipe or 2 pipe?

thanks

 

[Gasguru]

On a one pipe system both radiator conections join onto this single pipe.

On two pipe systems each radiator pipe joins onto a seperate pipe (flow and return).

 

[steveb1964]

On a one pipe system both radiator conections join onto this single pipe.

On two pipe systems each radiator pipe joins onto a seperate pipe (flow and return).

i might be being thick here but isn't there always 2 pipes going into a radiator?

i still don't get how to tell - sorry

 

[EliteHeat]

Take up the floorboards under the most convenient radiator. Trace the two pipes back to where they join up with the backbone of the circuit. If they both join to the same pipe then you have a one pipe system, otherwise you have a two pipe.

 

[Nige F]

Imagine a loop of pipe going round the permeter of the house.......the rads are above the loop and both ends of rad are dropped into the loop.....that is one pipe system

 

[steveb1964]

thanks all

 

[Agile]

In case anyone wants a hi-tech answer?

No, you dont? OK, so I wont bother!

Oh yes, I will because Bster ( although he jumps to too many [wrong] conclusions ) is keen to learn. I am almost wishing that he was one of my trainees because he is so keen to learn although he does need to have some of his overactive immagination surpressed.

The standard two pipe ( or parallel ) system delivers the flow independently to each radiator in the system.

The ( economy ) one pipe system in the domestic environment runs out of temperature towards the return end and fails to get enough flow into larger rads as its only by convection.

This means that if you put your digital contact thermometer on the flow pipes to each rad they will be virtually identical on a two pipe system but will be different on a one pipe.

Another clue is that most one pipe systems have a single pipe feed to the upstairs in the hall !!!

{{{ Its different for industrial. If I dont mention it then DIA will complain! Its common with industrial to have a large 2" or 3" one pipe system but the flow is not from a 30 y.o. 50w SMC pump but a big 400w circulating pump which gives enough flow that there is only 10­ C difference between the flow and return so all the rads have a good flow temperature. }}}

Tony Glazier

 

[doitall]

The standard two pipe ( or parallel ) system delivers the flow independently to each radiator in the system.

The ( economy ) one pipe system in the domestic environment runs out of temperature towards the return end and fails to get enough flow into larger rads as its only by convection.

This means that if you put your digital contact thermometer on the flow pipes to each rad they will be virtually identical on a two pipe system but will be different on a one pipe.

Another clue is that most one pipe systems have a single pipe feed to the upstairs in the hall !!!

{{{ Its different for industrial. If I dont mention it then DIA will complain! Its common with industrial to have a large 2" or 3" one pipe system but the flow is not from a 30 y.o. 50w SMC pump but a big 400w circulating pump which gives enough flow that there is only 10­ C difference between the flow and return so all the rads have a good flow temperature. }}}

Tony Glazier

I shall complain anyway Tony.

One day perhaps I shall tell you over an Indian.

 

[doitall]

The standard two pipe ( or parallel ) system delivers the flow independently to each radiator in the system.

So does a one pipe system.

The ( economy ) one pipe system in the domestic environment runs out of temperature towards the return end and fails to get enough flow into larger rads as its only by convection.

No it does't, a 1 pipe system will heat up just as quick as a 2pipe system, the length of the rad makes no difference, must modern 1 pipe systems
are fully pumped (not convection/gravity) and use sweep, tounge or injector tees.

This means that if you put your digital contact thermometer on the flow pipes to each rad they will be virtually identical on a two pipe system but will be different on a one pipe.
Another clue is that most one pipe systems have a single pipe feed to the upstairs in the hall !!!

It also has a return somewhere Tony, this could be together or dropping the other end of the building, the reverse return 2 pipe installion would only have a single pipe in the corner, and the return the other end of the rad circuit.so no if you saw a single pipe dropping in the corner, it may not be a one pipe system.

{{{ Its different for industrial. If I dont mention it then DIA will complain! Its common with industrial to have a large 2" or 3" one pipe system but the flow is not from a 30 y.o. 50w SMC pump but a big 400w circulating pump which gives enough flow that there is only 10­ C difference between the flow and return so all the rads have a good flow temperature. }}}

The pump is sized to the system exactly the same as a domestic, temperature differencials will be the same as domestic

 

[Agile]

Most of the domestic one pipe systems I have seen have been very low budget.

They have not used anything other than a standard tee and many had no rad valves either.

The one pipe was in 15 mm and with about five rads connected !

The usual SMC pump could only produce enough flow to get a return temperature of about 20 C below the flow.

The rads downstairs had a reasonable temperature but by the time the loop went upstairs the flow was at below 70 C .

Totally useless in real heating terms compared with a proper system.

The one pipe return is usually in the kitchen above the boiler.

You are seriously overdue a curry! Flora was complaining!

Tony