advice on mixer shower

[nabby68]

i am about to install a new mixer shower in my bathroom.
i have a cold water header tank in loft for the cold supply and a hot water cylinder for hot supply.
if i branch off the hot water cylinder in airing cupboard, can i take the branch up into the loft and across and down into the bathroom for the new shower? or will this affect the flow of hot water as it goes up into the loft and then down?
thanks

 

[Spark123]

Sorry, I added a post in error and was asking for my post to be deleted, not yours!!

To your original query, the way I understand is as long as the header tank is higher than the pipework the head of water will be there hence water will flow, you'll most likely need something to get rid of any airlocks in this pipework. As you can probably tell I am not a plumber, you'll be better off waiting for one to come along and confirm this.

 

[holty]

this is were hydraulic gradient comes in. if you were to run a hot tap that the pipe layout was situated lower than the pipe above flow of water would find its way to the lowest point hence a cold shower

 

[gasmarkone]

WOT???

 

[nabby68]

thanks for all your help fellas.
still not had a definitive answer though.
my gut instinct is that it will work but the flow rate and pressure would be poor at the shower head, so i might think about installing a pump
any other comments would be appreciated

 

[ChrisR]

You're right. It'll work, a bit. You need a manual air vent to get the air out first time you fill it. Going up and over makes no difference whatsoever if you take the feed from the right area(ie not off the vent pipe) except for the resistance of the length of pipe.

But the HEAD is likely to be a problem - if it's only from the floor above the shower, the flow will be poor. If you use big pipes and a suitable low pressure shower, it can be reasonable.

 

[nabby68]

thanks chris r.
i will be teeing off at the hot water outlet pipe on the the hot water cylinder which is in the airing cupboard and then running it upwards into the loft.
i think iwill install a pump. any ideas what type to look out for? and also i am thinking of running a new cold feed from the header tank into the pump, is this a big job ie tapping into the existing header tank.
ive also heard that a venturi shower can sometimes help with a poor hot supply, but am i right in saying that these run off mains cold water?