"IMM" wrote in message
...


I could use 400 squ foot of flat plate collector on the roof, twice
the
area, and produce the same volume of solar hot water as the Thermomax
solar
collectors which takes up half as much square footage.

The area is "very" important in this instant. Is that clear?

Yes, but efficiency is independent of that IMM.

Thats tantamount to saying a 5oKw boiler is twice as efficient as a 25Jw
one.

It is not. Solar collectors produce hot water. Some produce more than
others for the same area, hence more efficient for a given area.




No.

Efficiency is the ratio of converted power out to power in .

The area doesn't come into it.

Are you saying that for a given solar collector, if you have two
installations of _the identical model_ but with installation X having a 1sq
m area but Y having a 2 sq m area, then because installation Y has an output
that is twice that of installation X it is necessarily twice as efficient?

No?

Well, that is the implication of quoting a bogus specification like
"efficiency per square metre".


Or to put it another way. I have installation X which is 1 sq m and I can
calculate it's efficiency is 60%. The efficiency of installation Y is still
60%. It has twice the input power, but also twice the output power.



--
Richard Sampson

email me at
richard at olifant d-ot co do-t uk