Dear Andre,
If you
add 5 to 5 you have 10, and 5+100=105. In both cases the increase is the same,
but their relative changes are 100% and 5% respectively. So we have to
clarify about what changes we are speaking about. Any way for homogenous
materials R is simply proportional to thickness x ie R=r*x
It would be very interesting for me
to know the source US data. In USA they still frequently use Btu as the energy
unit= 1058J, 1ft= 0,305m, 1F=0,55C,1pound=0,405kg ,Probably the conversion
between them can be done as follow R US [hr-sqft-F/Btu]/5,74 =
R SI [s-m2-K/J]. The European unit is roughly speaking 6 time
bigger.
Rene's remarks are great-one have to take
into account much more data then you proposed to calculate the total heating
power of your house. Once again about "enough". If the price of energy
is zero you can use very poor insulation and it will be optimal one (from
economic point of view). When "energy prices might sky rocket some
day" such house would desequilibrate your budget (or rather mine). I
observe such phenomenon in Poland. Since 10 years thousands and thousands
of old big blocks (immeuble) and small houses are additionally insulated because
the energy costs much more now.
Perheaps when you are
speaking "enough insulation" you are thinking about "friendly
house" - friendly for your family,pocket and enviroment.
Greetings
Henryk
-----Original
Message-----
From: Coralie & Andre de Bouter <m.ep@laposte...> To: strawbale@amper....muni.cz <strawbale@amper....muni.cz> Date: Tuesday, June 25, 2002 2:23 PM Subject: Re: [Strawbale] At what point (R value) do we reach 'enough' insulation?
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