Hot water pressure on a vented system

[sinc9603]

Hi, I have looked through a few of the threads and googletastic but no such luck in answering this probably simple question so please may someone help.

In an indirect vented system, cold water storage tank in the loft, hot water vessel on the first floor, is the head from the cwsc usually enough to give adequate flow to the bathroom taps to the first floor, or is there normally a pump on the hot water side? The only reason I ask as if its gravity, is it just simply a case that the hot water is pushed out of the top of the tank (hot water at the top as it's lighter), by the colder water from the bottom of the cylinder?

Do most/all newer houses have secondary circulation systems to prevent dead legs, or is it only on bigger properties?

A bit about why i'm asking - I'm in the Armed Forces, currently away from England and am taking a distance learning (theory side at the minute, practical when I get home) course in plumbing. The literature is a bit hazy about the above question so I thought it easier to ask.

Thank you very much for your help guys.

(I have already posted this earlier and fluffed it so apologies, I couldnt delete it)

 

[Dan Robinson]

Pressure (well actually flow) will depend on pipe size, fittings, taps/showers and the actual height of the cold water cistern (more specifically the water level) above the OUTLET of whatever you are referring too.

is it just simply a case that the hot water is pushed out of the top of the tank

Yes, but not for this reason:

(hot water at the top as it's lighter), by the colder water from the bottom of the cylinder?

 

[flameport]

Do most/all newer houses have secondary circulation systems to prevent dead legs, or is it only on bigger properties?

No, only used in very large or unusually shaped properties, and then only on the better specified ones.

The majority of new builds are done as cheaply as possible and anything concealed from view such as plumbing or electrical is likely to be the very lowest cost and specification.

CWS and gravity hot water are not normally fitted on new build either, it's typically a combination boiler or mains pressure unvented cylinder. Sometimes both.

 

[sinc9603]

Dan_Robinson - Makes sense about the cistern water level and the height from the outlet. Obviously I know I'm not learning the conventional way so thank you very much for your help.

Flameport - Also mate thanks for the heads up. The books I'm reading are a bit all over the place with regards to secondary circulation and pumps etc. Much appreciated.