RE: Homemade Radiator (Was: Swish @ B&Q)

[keithwwyse@xxxxxxx]

On 26 Mar 2001, at 10:03, Keith Doxey wrote:
>"You are putting the hottest water (flow) at the to of the
radiator
>which means the ceiling will be toasty warm in no time at all. The
>pump will have to counter the natural convection forces in addition
>to
>pumping all the water with no gravity assist."

The air convection current does this in any case, but the ceiling will
be well insulated, as will the walls (when I get around to it) so there
should be less heat loss. Also this design should produce a
stronger convection current, so hopefully heating more air and the
room more quickly. The enclosures will be made to direct the
current outward as well.
Well that would be true in some systems, but mine is a gravity
feed, so the pump and radiator system should have a bit of
pressure on it, hence it will be able to travel up to about the height
of the water tank. The water will be cooling through the radiator, so
convection would pull more through.

>"Wherever you locate your temperature sensor, it will detect that
>you
>have reached your desired comfort setting when the floor level is
>still much colder."

-- I don't have any temperature sensors. I haven't ventured into X10
as yet, but the plan was to get some thermostatic rad. valves and
put them in just above floor height.

>"Have you considered "baseboard" heating or underfloor.
When I
>move and
>get round to having central heating, they are the options I will
>consider."

I'm living on the top floor of a maisonnette, so I don't think my
downstairs neighbour would be happy about me fiddling about down
there.

>"As to moving radiators away from windows, AIUI the original
>concept
>was to prevent draughts from leaky windows. If you have double
>glazing
>there shouldnt be much heat loss through the glass, if you dont
>have
>double glazing then surely you want to draught stop as many of
>the
>leaks as possible and then warm any residual breeze to stop cold
>spots."

(AIUI? - haven't seen that before)
Well there _shouldn't_ be draughts but the windows that are in at
the moment look real cheap and nasty compared to my Mum &
Dads Penicuik windows. I don't know who made them as they
came with the house. They do leak cold air, and don't seal well
when shut.

>"If you move the radiators to other parts of the wall then surely
you
>lose that wall space because any object in front of the radiator (eg
>Sofa) will restrict the heat dissipation."

I will be able to reclaim the space in front of the window in
compensation. In some of the rooms I will be putting tables here to
grow plants on. But the rads will have very little in front of them,
and since they go most of the way to the ceiling, there won't be a
lot there to block them.

>"To maximise heat dissipation to need to maximise surface area,
>hence
>the fins on a car radiator.

Yes I was going to attach empty copper tubing (horizontal or
vertical?) to dissipate more heat. Pushes up the cost some though.

>"Maybe I have missed something really obvious, but I dont see
>how your
>radiator design will have benefits other than being more artistic
>than
>a white radiator."

I'm hoping it will be in several ways.
- The tubes will be painted matt black, which radiates IR heat more
efficiently. (Enclosures will be made to cover this and so look
better)
- The copper is slightly more effective at transmitting heat through
conduction than the steel of the current ones, and the walls of the
tubes are thinner.
- The fitting to the wall will be wooden blocks on internal walls
rather than metal brackets on external walls, reducing heating loss
through the wall. Also the enclosures will insulate against the wall,
and be reflective all round inside to emit the IR heat effectively
through vents.
- The individual tube design and the extra empty tubes should
increase the surface area significantly.

Since I have not built anything as yet and the idea is still
theoretical, I'd appreciate any input from anyone on whether this
will work or not, or any way of improving it further. I'm basically
aiming for the most efficient radiators possible. But I have a tight
budget at the moment.

Thanks

Keith (the new one)

"Someday Pinkie..."
Keith Wyse

"Someday Pinkie..."