15mm to 22mm?

[grifter]

These are the pipes coming from upstairs and feeding 5 rads on the ground floor.

I will be changing the location of the current rads, 3 around the same area, but 2 are going out in the conservatory and will spam over a distance of approximately 8 metres.

My question is can l tee off the existing pipes with 15mm to the first 3 rads which are staying around the same kind of distance away, but then change to 22mm for the longer run in the conservatory and tee off 15mm to the other 2 rads for better flow rate?

Does this sound feasible?

 

[blup]

Keeping 22mm for as long as possible will surely maintain or improve flow better

 

[grifter]

Keeping 22mm for as long as possible will surely maintain or improve flow better

So branching off the 15mm up to 22mm for 2 rads will be ok to do?

 

[blup]

So branching off the 15mm up to 22mm for 2 rads will be ok to do?

I (mis) read the whole supply as being converted to 22mm, so probably not a significant difference

 

[grifter]

I (mis) read the whole supply as being converted to 22mm, so probably not a significant difference

No just the 2 rads in the conservatory which the furthest one is about 7 metres up the far end from the 15mm pipe.
So change to 22mm or just use 15mm?

 

[oldbuffer]

1. The maximum flow rate will be determined by the narrowest pipe. So there is no point going up to 22mm after a length of 15mm.
2. If the run to the nearest 3 radiators is a 22mm "spine" with short spurs to each radiator in 15mm, then 15 mm runs to the conservatory radiators may be OK. Depends on the size of the radiators, but most likely OK up to around 4kW.
3. If you are extending the spine to the conservatory, stick with 22mm as far as practicable.
4. Be aware that radiators in conservatories should be on a separate zone with its own zone control (motorised) valve. This may not be the case if you have external quality doors between the conservatory and the main property.

 

[grifter]

1. The maximum flow rate will be determined by the narrowest pipe. So there is no point going up to 22mm after a length of 15mm.
2. If the run to the nearest 3 radiators is a 22mm "spine" with short spurs to each radiator in 15mm, then 15 mm runs to the conservatory radiators may be OK. Depends on the size of the radiators, but most likely OK up to around 4kW.
3. If you are extending the spine to the conservatory, stick with 22mm as far as practicable.
4. Be aware that radiators in conservatories should be on a separate zone with its own zone control (motorised) valve. This may not be the case if you have external quality doors between the conservatory and the main property.

The kitchen goes out into the conservatory. It is open plan, hence adding radiators out there.

Currently, all the downstairs plumbing is in 15mm. No 22mm at all.

 

[jj4091]

Currently, all the downstairs plumbing is in 15mm. No 22mm at all.

What even your heating flow and return from the boiler (presuming you have a combi )

 

[grifter]

What even your heating flow and return from the boiler (presuming you have a combi )

Yes have a combi and flow and return is 22mm from the boiler.
But 15mm flow and return coming down to feed downstairs rads is what l meant.

 

[oldbuffer]

1. If the conservatory is open to the rest of the house, sounds as if it contravenes Part L of the building regulations.
2. You need to do a proper heat loss calculation for the ground floor and conservatory. Whether or not 15mm pipe will support the requirement can then be determined.

 

[grifter]

1. If the conservatory is open to the rest of the house, sounds as if it contravenes Part L of the building regulations.
2. You need to do a proper heat loss calculation for the ground floor and conservatory. Whether or not 15mm pipe will support the requirement can then be determined.

I'm not really interested in all that. It's only to do with emissions etc blah blah blah The conservatory is insulated above and has ceilings and warmed up well enough with electric storage heaters before it was insulated, so l'm just going to do it.