is this the right solution?

[obseen16]

hi all,

recently been doing the plumbing work on a loft conversion which requires a sink to be installed up there. the current system in the house is gravity fed. however there was a shower pump, so i figured just tee off the pump to supply the loft sink with hot and cold, but the pump wont pump to the tap. but the shower still works fine, this is probably due to negative head pressure and the pump is not a negative head pump. so the only option i have thought of is to tee off the mains to the header tank for the cold and get an instantaneous hot water thingie also. would you guys of more experience do the same? also the mains pressure to the house is really bad, at the ground floor the pressure is at 2 bar, so would it be alot lower in the loft due to the height, its only a 3 story house including the loft but most of these instant hot water gizmos require a minimum of 1 bar, do you reckon it will have enough pressure?

hope you can offer some advice.

many thanks all.

J

 

[Mike Jackson]

1 bar is the equivalent of approx 10m head so with pipework resistance you'll probably still have around a bar at 3rd storey level.

When you say instant do you mean point of use? A point of use water heater such as a Heatrae Sadia supreme will work on around 0.4 bar. A mains instantaneous heater such as the Redring powerstream can work on as little as .75 bar if the lower power model is chosen.

Mike

 

[NickH]

Why not just get a negative head pump?

 

[obseen16]

cheers for that guys, was going to get a negative head pump but the customer didnt want to get another pump as the one they have at the mo is not even a year old, so the pump idea kinda went out the window.