DHW recirculation system

[Rookieplumber]

Hi, anyone out there able to give me some advise on the above?
My heating engineer has fitted my pellet boiler and thermal store, and I am now left with the task of connecting it to my self installed UFH system and my DHW system.

The renovation project has 3 areas requiring DHW all at opposite ends of a 20m long barn. Therefore I had envisaged running three separate circuits from a manifold in the boiler room to ensure sufficient flow rate etc.. However, the heating engineer has recommended that I fit a DHW recirculation pump given the length of the pipe runs to save water and that it will be efficient and comfortable in the long term due to limited heat loss in the pipes which will be heavily insulated.

I have studied some system diagrams for the aforementioned principal but cannot see how this will work with separate flows from a single distributor/manifold using a single circulating pump.....am I being stupid? Is there a way to do it? I don't really want to have a 'ring' circuit if I can help it as I think that this will require an even larger diameter feed pipe to cover all three areas with sufficient flow.
Help please!

Cheers

 

[ShaunCorbs]

why not get your heating engineer to connect it up for you prob cost you less in the long run esp if you dont know what your doing and btw its called a secondary return

 

[snowhead]

It has to be a ring.
Larger flow than return.
Eg 28mm flow and 15mm return with pump in circuit.

 

[AWheating]

whats your mains supply flow and pressure like?

run the pipework the normal way, dont use manifolds from the plant room area. make sure its all in copper with 25mm lagging.

 

[Ermintrude]

Or mLCP as that's approved now

 

[Ermintrude]

Use 10mm returns and balance on each. Keep flow slow and low

 

[oz-plumber]

Google 'hot water ring main', there should be enough info available for you to understand the principle and give you schematics on how it's done.

Just a side note, there are many way to stuff it up if you don't have the experience to install one correctly and there are legionella risks to be taken into account also.