Post by alan_m Post by Brian Gaff (Sofa)
Not sure they should be compulsory, I use Storage heaters and have been
pleased with them except for the clunky mechanical louvers getting stuck
I thought the whole idea was eventually to use a reversible heat pump and
then it could be more efficient.
The OP suggested that a "heat pipe" was going to be installed along with
an electric boiler so I assume that maybe he was referring to a heat
pump (air sourced). He doesn't mention cost but possibly no change from
Heat pipes are amazing. They use phase change (vapor changing back
to fluid, releasing the heat of vaporization) as a transport mechanism.
Some hobbyist computers have heatpipes in the CPU heatsink, and
the transport mechanism is so powerful, it has better thermal
conduction properties than an equivalent diameter of solid copper.
That's because it is an active transport, whereas solid copper
is merely a passive transport.
Heatpipes don't have to be expensive to work.
They can also "work uphill", if the inside surface of
the plumbing is "sintered" and the capillary action
that results, allows condensed fluid to travel uphill.
A more preferred situation, is for the condensed fluid
to flow downhill back to the heat source (storage heater).
You could do this:
In the diagram, the working fluid in the storage heater (water),
does not mix with the working fluid in the heatpipe (pure alcohol).
The entire heatpipe only has a few teaspoons of alcohol. It does
not have, nor need, gallons of alcohol. The transport is vapor
phase, and little vapor is needed.
| +== Radiator
+-------------+ heat pipe | +==
| |+------------------------+ +==
| Storage || +-----------------------+
| heater || | (hollow) condenses
alcohol [Vapor phase transport]
The benefit is, you don't need the storage tank in the upstairs room.
Now, the problem with placing a heatpump on the left hand
side of that picture, is the need for winter heating and
summer cooling, to work with the same gubbins. In principle,
I think you could make it work. But... it might not have
the degree of efficiency desired. If I only had to set it
up for one season (only for winter heating), I could
make it work slightly better.
Just as the general discussion of heatpumps leaves me cold.
Heatpumps are a low quality heat source, requiring extraordinary
efforts to transfer the heat into a room. Adding a heatpipe
to the picture, is just additional aggravation, making
a "marginal situation", "more marginal". Stupid even.
The electric storage heater, the electric part is
"high quality" heat. When you couple it with the
storage part, that degrades the quality a bit. If the
water cools down to 40C, what do you do with the
remaining heat ? That's not a high enough temp
to really heat the room any more.
Heatpipes have a design power limit. For example, if
you put more than 200W into the CPU heatsink, all
of the working fluid in the pipes remains in the
vapor phase, and the nice thermal pumping action
stops. The idea then, is to ensure the heatpipe is
big enough, for the application, so it doesn't "saturate".
Heatpipes have apparently already been used in
air-to-air heat exchangers for R2000 homes. But I
haven't seen any pictures of working units of that type,
so I don't know what the implementation looks like.