Two rads, one supply - theory vs reality

[Ghandi]

Morning all,

New member here, so hi and thanks for taking the time to read this.

I'm replacing an old undersized rad connected by 15mm copper to the 22mm flow/return on my system.

I need to install 10k BTU/3kW but wall space means this will have to be in two rads, one at each side of the room.

I wonder if I can take the original 15mm from the old rad and tee it to supply both new rads in parallel.

Theory says that the 15mm will have enough in it to supply both new rads, but has anyone done this in reality and is it satisfactory?

I'm willing to tee both into the flow/rtn if needs be, but happy to save myself time and fittings if it's not necessary.

I would welcome anyone's opinions on this.

Many thanks

 

[joni os]

!5mm will be ok up to 5Kw. Convenience and neat finish being a consideration,and as you rightly say,in parallel,not in series.

 

[ShaunCorbs]

I have don't think they look too bad tbh (I like the look)



But you need to connect them at both ports I used some chrome pipe and 4 1/2 - 15mm chrome male irons

 

[Ghandi]

Thanks for the replies. Can't do as the pic because they are going to be at opposite sides of the room. They will have to be two stand alone rads with separate trvs. Will this cause a problem?

 

[ShaunCorbs]

Thanks for the replies. Can't do as the pic because they are going to be at opposite sides of the room. They will have to be two stand alone rads with separate trvs. Will this cause a problem?

Need to t off before the trv but don't see why not, they will require balancing like any rad

 

[Ghandi]

Will the rads being a difference distance from the flow/rtn make any difference? Should I aim to get the 15mm to each rad a similar length or will this be accounted for in the balancing?

 

[ShaunCorbs]

Will the rads being a difference distance from the flow/rtn make any difference? Should I aim to get the 15mm to each rad a similar length or will this be accounted for in the balancing?

no will be fine just balancing

 

[Ghandi]

Ok, so after removing some lagging I find that the original rad is tee'd off the flow with 5' of 22mm and this then reduces to 15mm for the remaining 11' to the rad. If I still want to install two rads should I...

A) tee the 15mm at the end
B) have a second 15mm teed off the 5' of 22mm
C) do it properly and go right back to the main flow

If it's answer C, would I need a length of 22mm before reducing to 15mm

 

[Ghandi]

Ok, so after removing some lagging I find that the original rad is tee'd off the flow with 5' of 22mm and this then reduces to 15mm for the remaining 11' to the rad. If I still want to install two rads should I...

A) tee the 15mm at the end
B) have a second 15mm teed off the 5' of 22mm
C) do it properly and go right back to the main flow

If it's answer C, would I need a length of 22mm before reducing to 15mm