"Clive Summerfield" wrote in message
...

"IMM" wrote in message
...

"Julian Fowler" wrote in message
...
On Thu, 7 Aug 2003 17:20:35 +0100, "IMM" wrote:


"Julian Fowler" wrote in message
.. .

snip

Hmmm ... I don't suppose its a *teeny* bit possible that this might
apply to US-style houses built in Florida, and might not be
applicable
to conditions here?

Did you read it? No.

Yes, actually ... additionally, I clearly understood a lot more than
you did. Start with the very first page -- note the temperatures
cited (attic temp reduced from 135F to 120F)? Note the fact that this
an academic research project report and "not intended to represent the
views and opinions of the Florida Solar Energy Center". Note that the
attic spaces shown are filled w/ HVAC ducting??

If they work in Florida they will work here. A
barrier under tiles is well a barrier under tiles anywhere.

Who said anything about tiles - the report, which you quoted, referred
to shingles - a different roofing material used in a different
construction technique and a different climate from that in the UK.
Plus, you were citing this to back up your assertion that a/c is
unnecessary in this country ... try finding a house without a/c in
Florida!

read the site some more


This quote seems applicable...

"tile roofs experience less attic heating and thus would likely produce
less
benefits from an RBS (Beal and Chandra, 1995; Parker and Sherwin, 1998). "

Grey tile creates an amazing amount of loft heat.

Most of the emphasis of the report is on energy savings from reduced power
consumption by cooling systems - some 9% on average. However for those
homes
without aircon - and for the UK I would imagine that is pretty damn near
most - such savings are of no consequence. Then there is the average
decrease in interior temperature of 2 degrees farenheit, but that is for a
sample where 90% of the homes used composite shingle rather than tile.

So for the typical UK home with no aircon and a tile roof, the benefits
are
minimal, and far outweighed by the cost of installation.

A nice idea if you live in Florida, but bugger all use in the UK.

Cheers
Clive




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