Looking to fit a Trevi Boost. What do I need to check first?

[DarrenThomas]

We are finally getting around to replacing the bathroom and I've been looking at the Trevi Boost as the option for the shower. The hot tank is on the same floor, the cold tank is in the loft (base approx 0.7-1m above the current shower head).

The current bath plumbing is 22mm from the tank to the bath tap and the cold is 15mm from the mains and seems to come hurtling out.

Needless to say I know that "hurtling out" probably isn't quite accurate enough to ensure the Boost is right for my circumstances.

Can someone (I imagine Softus if he is around) tell me exactly what I need to measure to ensure that this isn't just going to be a waste of money?

 

[Charnwood]

This might be of some help:

 

[DarrenThomas]

We'll I've just done a flow rate test @ 18:00. At bath tap level (bathroom is upstairs) I filled a 12 litre bucket right to overflowing in 40 seconds with cold and 50 seconds with hot. That's assuming that bucket is 12 litres to the brim instead of 12 litres to near the top.

So that puts me at 18 litres/min mains cold and 14 litres/min cylinder hot at bath level.

The base of my cold tank is 0.65m above the current shower head. My shower head is 1.55m above my taps.

Is any of that useful or do I still need to know flow rate/pressure at shower head level?