"PeterC" wrote in message
.. .
On Sat, 30 Jan 2010 10:57:11 GMT, pete wrote:

Before xmas we bought a new (cheapo) duvet, as it was cheaper
to replace the old one than the cost of getting it cleaned.
Anyway, right out of the bag the new duvet didn't appear as good
as the old one. They were both rated at 13.5 TOF, but the new
one was obviously thinner. It wasn't as warm either (even taking
the colder weather into account) and we needed an extra blanket
on top.
Fast forward to this week and we got another cheapo duvet - this
time from Sainsburys, which again is rated at 13.5 TOG and is much
better then the last one we bought (compares well to the original
one). So purely out of interest, I'd like to test if the TOG rating
of the various duvets measures up - has anyone else tried this?

From a DIY perspective, I'm planning on measuring the temp. under
the duvet, while warming the bed with an electric blanket (and having
the room temperature more-or-less constant). The idea is that the
greater the thermal insulation, the higher the under-duvet temperature
will be. The tricky bit will e converting this temperature to a heat-
loss figure and then to a thermal resistance figure.
Any pointers on how to do the sums would be appreciated.

As a bit of an aside, I've a 4.5 TOG that's better than a cheap 9 TOG -
the
major difference seems to be that the 4 TOG is Hollofill fibre.

I recently bought a 7.5+3.5 TOG combo from Ikea and paid the bit extra for
Hollofill. The 7.5 part is lighter than my old 4.5 and just a bit warmer
(about 15 years between purchases, to 'newer' material?).
--
Peter.
2x4 - thick plank; 4x4 - two of 'em.

Do you think the weight and flexibility of the duvet has an effect? If it
moulds itself to your sleeping form it may give the impression of being
warmer than one which leaves gaps down your sides.