Shower pump pipe sizing

[phredd]

Hi folks.
I,m installing a shower cubicle/sauna, and it needs a minimum of 2 bar. I have a 3 bar pump, which has 22mm connections, but the connections on the shower cubicle are 15mm.
The instructions with the pump say that "the outlet piping may be 15mm for a short run otherwise the performance may be affected." the cubicle is 3 meters from the pump. Would you consider this a short run?
There are existing notches which will take 15mm and I would like to avoid cutting more out of my floor joists.
Thanks.................Phredd.

 

[ChrisR]

WOUld make no noticeable difference.
Most showers send combined H and C up 1.2 metres of hose which is only 10mm diameter, if you're liucky!

 

[phredd]

Thanks Chris.
Phredd.