Ring Mains Design

Good Day All,

I was wondering if any of you can assist me with some considerations and tips on designing a ring mains for a three storey building..We plan to do it all in copper…

The Storage Unit and Heat Pump water heater will be at basement level..

Then we will have

1) 4 apartments (4ppl per unit) on the 1st floor
2) 8 apartments (2ppl per unit) on the 2nd floor
3) 10 apartments (2ppl per unit) on the 3rd floor

I usually only work on domestic installations, but I am clueless on these bigger designs…

Info that I require..

1-) Piping diameters upwards to each floor
2-) Piping diameters branching off to each floor
3-) Piping diameters branching off into each apartment.
4-) Pump(flow rate) required to handle this
5-) How will it be controlled, as we do not want the ring mains pump to circulate throughout the day. it is residential and we will only need circulation around 16:00 to 08:00..

Any info will be appreciated…