Nigel Goodwin

There have been various solar water heating schemes over many decades, the problem (as always) is down to how viable they actually are!.

The 'Centre for Alternative Technology' (C.A.T.) in Wales does a lot of work in that line, and is well worth a visit if you're ever in the UK - makes for a great day out.

__________________
PIC programmer software, and PIC Tutorials at:
http://www.winpicprog.co.uk

crashsite

I went back and looked at the referenced article and here's a paragraph. It's actually "calcium chloride" (my faulty memory):

"Our intermittent absorption solar icemaker uses calcium
chloride salt as the absorber and pure ammonia as the
refrigerant. These materials are comparatively easy to
obtain. Ammonia is available on order from gas
suppliers and calcium chloride can be bought in the
winter as an ice melter."

rjvh

i am familiar with your reference article
but this article is published a few years ago and this guy is from canada
plenty of calsium chloride there but in cambodia it's not that easy to obtain
i bet in brisbain it's also not a common good that you buy on every street corner
amonia is again a different story
in a country with some industry it will be availible but after 9/11 people ask a lot more questions what you gona do with it
it's still nasty stuf which you can use in manny nasty ways

as for the sollar shemes in overcast windy and rainy parts of europe
i class england in that category
that is just showing the will to do somthing about it than that it makes sence
max energy what the sun deliver on 1 square meter is 4.8KW a day (12hours)
thats in quatar, sahara, texas and australia
your are extreemely good to build a sollar colector with an efficiency 65%
you can tweek it but to get 10% more cost you 50% more
that leaves you a bit more than 3 KW:12 Hours = 250watt an hour
how manny sun hours you have in england ? (holland is 51% sunny of the total sun hours a year)
but temp is a lot cooler and the chill factor is also a problem because i tend to be always windy
this can be tackled severals ways but it ad on the cost of making the colector
a sollar collector is by far the most efficient way to get energy from the sun but is comecialy only intresting if it is heavely subsidized (which is in europe the case)
or in sunny parts of the world year round

Pommie

Calcium Chloride is readily available as damp absorber in most supermarkets. If it isn't available then Calcium Carbonate is available as ground up sea shells. Mix Calcium Carbonate with Hydrochloric (muriatic) acid and you have the Chloride. Ammonia is also available in the cleaning section - it's weak but can easily be strengthened. Ammonium Sulphate is available as fertiliser, mix it in solution with Calcium Hydroxide (slated lime - builders supplies) and you have weak Ammonia solution (+Calcium Sulphate as a precipitate).

As you can see most chemicals are available, you just need to know where to look.

Mike.

rjvh

you've ever been in cambodia ???
the outback in australia is better stocked then here

if you know what we have to do to get the simplest things here you would be supriced
it's now much better than 7 years ago but still a big hassle
i never came acros ammonia here not even the weak one for cleaning
everybody is talking about pic ic these days
i can't buy even a simple opto coupler, +/- 7 different numbers of the Cmos 4000 family is availible here not more
solenoid valves 12V and 220V availible only in one size (to small where i need them for)
ect ect

crashsite

We (especially us Americans...although I know that will irk a few other "first-world" users here) often do not appriciate that every day, for us, is like Christmas morning when it comes to having/obtaining material things.

But, I would comment to you that there is a famous saying in the selling business: "Adversity brings opportunity". Cambodia is pretty hot. I've never been there but, I've been to Singapore and, that zone is just hot every day!

Some enterprizing Cambdian will likely find a way to take advantage of that tropical sun and make a pile of cash. Perhaps selling "low cost cold" could be one of them?