On 15/02/2013 13:39, Onetap wrote:
On Thursday, February 14, 2013 10:59:59 PM UTC, Andy Champ wrote:

It warms a little bit of the vertical, not all of it. As FredXX found.

So FredXX says, but I am asking the company to apply their wisdom and
say why that should be; since I don't think it would happen unless there
are some other factors involved.
I have spent a lot of time designing, commssioning and balancing fluid systems.
I can't see it happening, unless there's something else happening.

Surely the something else is convection isn't it? When the hot, light
water goes in at the bottom, it'll float up to the top of the rad,
flooding through the top "tank". Flow rates inside the rad due to the
pump are low, so convection can dominate and the hot water floats up
through the first few channels. If it didn't, BBOE would never work.
The cooler water already in the rad will pool at the bottom, where the
exit ought to be. If the exit is at the top, then it'll be the hottest
water in the rad that gets pushed out by the incoming water - obviously
not what you want. A notional BTOE (as opposed to TBOE) rad will only
get hot up one end and along the top.


It is plausible with TBSE connections,

It is unlikey with TBOE connections. If you look at a TBOE radiator,
there are equal flow distances between the inlet and outlet connections,
regardless of which vertical channel the water passes through.
You would expect there to be equal flow rates through all of the
radiator channels, regardless of which connection was top or bottom.

No. I would expect convection to be the driving force in deciding which
channels the water flows through. If hot water finds itself at the
bottom of a cooler channel, it'll flow strongly up it. With the exit at
the top, a large pool of cold water will accumulate at the bottom of the
rad.

Cheers,

Colin.