We currently have an oil boiler producing 50/70 kw linked to a 25mm 5.5m head Grundfos circulation pump serving zone 1 as detailed below (pressurised system).
The boiler is in the basement so there about 4 meters from the bottom of the boiler to the top of the radiator in Zone 1 office.
Zone 1 – Existing Offices – 4 meters above boiler (1[SUP]st[/SUP] Floor)
We are completing the offices on the third floor and would like to link them into the existing system as the boiler seems to have the capacity.
Zone 2 – New Offices – 12 meters above boiler (3[SUP]rd[/SUP] floor)
We have a Grundfos 40mm 18.5 meter head (40-185) pump but have some concerns about plumbing in the new offices.
The plan was to t-off at the boiler with a motorised 3 port valve between the two zones
Is the pump likely to be too powerful – exceeding the 1.5m/sec water rate if only 1 of the two zones were active?
Is 28mm sufficient for the run to zone 2?
Are there any problems connecting 28mm to a 40mm pump – would the pump be short of water in some way?
Are we way off the mark?
Mike
The boiler is in the basement so there about 4 meters from the bottom of the boiler to the top of the radiator in Zone 1 office.
Zone 1 – Existing Offices – 4 meters above boiler (1[SUP]st[/SUP] Floor)
- 14 radiators 19,000 watts total
- 28mm copper reducing to 22mm half way around run – final reduction to 15mm for some spurs and end rads
- 66 meters in 28mm (including return)
- 50 meters in 22mm (including return)
- 46 meters in 15mm (including return)
We are completing the offices on the third floor and would like to link them into the existing system as the boiler seems to have the capacity.
Zone 2 – New Offices – 12 meters above boiler (3[SUP]rd[/SUP] floor)
- 8 radiators 12,000 watts total
- 34 meters in 28mm (including return)
- 46 meters in 22mm (including return)
- 48 meters in 15mm (including return)
We have a Grundfos 40mm 18.5 meter head (40-185) pump but have some concerns about plumbing in the new offices.
The plan was to t-off at the boiler with a motorised 3 port valve between the two zones
- run 28mm the 17 meters (34m inc return) to the new offices (12 meters up and 5 meters across from the boiler),
- reducing to 22mm around the ring 23 meters. (46m inc return)
- t-ing off at 15mm to the rads 24 meters (48m inc return)
Is the pump likely to be too powerful – exceeding the 1.5m/sec water rate if only 1 of the two zones were active?
Is 28mm sufficient for the run to zone 2?
Are there any problems connecting 28mm to a 40mm pump – would the pump be short of water in some way?
Are we way off the mark?
Mike