SWH project part 16 - up and running

It's going! I'll be leaving behind a short list of outstanding finishing touches, and a couple of suggestions for future improvements, but in the meantime it's working: preheating the water for the laundry so the geyser doesn't have to work so hard, and thus saves fuel.

Solar Water Heater opening ceremony.  The first overcast day in ages, but was
actually just as warm and twice as humid.  Sweaty.

Some of my main helpers.

Re-fitting the heat exchangers (see here for why)

Lid back on after much intricate wielding of the hacksaw.

The brazing chap from Lahore was back doing some other work in the hospital,
so I got him to attend to a minor leak.

One last piece of colourful frazzled copper.

Snug as a bug in a rug about to chug a mug of... hot chocolate?  Glug!

SolarBot doing his thing.

Modest temperatures on a cloudy morning.  In the middle of a clear day the
panels hit 80°C, and the tank gets to 65-70°C.

Again, on a clear day the output beats 50°C.  This could be improved by
lengthening the heat exchanger coils, or by moving to a pressurised tank
with no heat exchanger.  The latter is almost certainly worth doing.  When
someone gets round to it...

Finished system.  For a given value of "finished".

Tank insulated and roofed.  Among the final touches I'm
leaving for the workshop guys to do at some point is to stop
the rainwater collecting on the platform and soaking into the
bottom couple of inches of insulation.  Preferably before the
monsoon starts in earnest.

Thermal expansion coupled with cycles of thunderstorms
followed by hot clear days has done for these strips we used
to hold down the glazing.  They'll replace them with some-
thing better and redo the seals...

(This one's an extreme example - the other nine seem to be fine!)

...which should hopefully stop this happening.  They'll also put some metal
sheeting along the top edge of the panels.

SWH project part 14 - glazing

Or possibly plasticking.

We got this twin-wall polycarbonate shipped up from Karachi.  Bizarrely, it was
only available in sheets 19' x 6'11", so all of the panel sizings were designed
around this.  We had them slice them into 5 equal parts for easier shipping.  And
on the right panel at least, easier mounting too, as we've had one or two minor
alignment issues since we first put the frames up.

This is the satisfying bit, like peeling off a 7-foot plaster.  The lighter blocks are to
keep the glazing off the pipes, should it bend/sag once it's warmed up.  Yes, we
probably should have painted them black too, but that would have wasted another
half-day while we waited for it to dry.

Whether by learning from experience or from fluke, we did a better job of
keeping things perfectly straight when we constructed the left panel's frames,
so all the glazing just dropped neatly into place.  Aah.

All glazing in place, secured down by wooden slats and liberally silicone'd.
And now ready for its first wash by the looks of it.  This is a generally dusty
place anyway, but possibly being near the incinerator doesn't help.

Specially procured polyurethane insulation for the backs of the panels.
The Pakistanis' favourite cheap styrofoam is no good as it has a tendency to
melt at the temperatures we'll be asking of it.

3 down, 7 to go.  We've also insulated all the hot pipe runs with fibreglass wool.

Trying to screw stuff into place while holding it upwards onto a slope of 50° is not
easy.