RE: Heat Recover, was: RE: NODE 0 Heat

["Ian" <ian@xxxxxxxxxxxxxxxxxxxxxxxx>]

>From: Jim Noble [mailto:yahoo-groups@xxxxxxx]
>
> What happens when you're not feeding cold water into the cylinder
though?

When are you ever not feeding cold water into the cylinder?

Surely the hot water tank is always under pressure, so that if usage
outstrips capacity you just get cold water from the tap, rather than risk
the boiler running dry?

> Do you have a small secondary tank in the supply pipe?

That's what I said. ;)

Rather than this: http://tinyurl.com/6ecex

You have this: http://tinyurl.com/4zca2

>> this is the system used by most solar water heaters, I believe.
>
> I thought they used a secondary coil in the cylinder?

Only in countries prone to freezing, where the externally exposed loop
typically contains anti-freeze. In hotter climes, it seems that the tank is
fed directly.

Either way, the concept is the same - you preheat the water to make it
easier for the boiler so you consume less fuel. Whether it's practical to
use PC heat as a heat source is the real question I guess.

Ian.