Cold manifold setup?

[BotusBuild]

Following on from the HEP20 manifold thread I was wondering whether this is allowed. As my planned location of the cold and hot manifolds lies between where the mains feed into the house is, and where the HWC will be, I was wondering whether the cold taps manifold could just be a loop as shown in the diagram?

 

[JohnMo]

The normal for an unvented cylinder is cold goes to UVC, and is then taken to cold consumers at the same pressure as the cylinder from an output at the pressure control valve.

 

My UVC was a retrofit, so the incomer into house has a PRV, it goes to the UVC, but I have a manifold for cold services just teed off after the incoming PRV.  The white top pipe going to cylinder.

[jayc89]

Loops are fine, they allow for max flow. Assuming an unvented cylinder, you need to be careful to avoid back pressure from any mixer taps, so you'd want;

1) a PRV on the mains coming in, before the cold manifold

2) a NRV on the supply to your hot water manifold

[OwenF]

My hot and cold manifolds straddle my UVC. Below pic is prior to UVC going in, but the valve’d pipe entering the cold manifold is straight off the balanced output of the cylinder PRV

 

(The reason for the tee at that junction is because it’s temporarily going on to the old CW pipe network that will be decommissioned)

 

As above, I’d stick a PRV before the manifold so that all mixers are balanced. Don’t know if just tee’ing straight through to the UVC cold feed would be any better/worse hydraulically than looping round the manifold.

Edited February 20 by OwenF
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