BG> possibly due to a higher demand for sub-floor air circulation
BG> space due to our excessively hot and humid climate.

RS> Thats just the old style approach used when you dont have
RS> real climate control. We have funky stuff called air conditioning
RS> now. Which actually makes that approach not that viable.

KR> being an old fart, you probably haven't come across
KR> the funky concept of passive climate control,

RS> Poor old Keef, its been extensively used here for example, before
RS> the modern approach was used instead. And I use it extensively
RS> myself. BUT, in ADDITION to the modern stuff, not instead of.

KR> i put the above sentence through a
KR> comprehensibility analyser, and it said "huh?"

Poor old Keef, I cant help it if your comprehension
is overloaded with dog shit, thats your problem.

KR> saves scads of electricity,

RS> Thats the theory anyway. The practical reality is that in many
RS> areas like here, no one much uses it alone anymore, for the very
RS> simple reason that it never gets anything like acceptible end result.
RS> So you go the other route instead. It was a viable route when the
RS> modern stuff wasnt available, but it aint that satisfactory at all.

KR> it said the same about this one too.

Thats your problem Keef, if you are too thick to understand it, too bad.

RS> I actually made extensive use of it myself, but thats only
RS> useful when its not the extremes of summer and you have to
RS> use the other for the hottest weather, to get viable conditions.
RS> Tho it certainly does quite dramatically reduce the say number
RS> of days the modern approach has to be used.

KR> up north, sub floor ventilation is one
KR> of the things that contribute to that.

RS> Its not really that that gives the benefit, its predominantly
RS> the extra height. When the outside temp is past what you find
RS> acceptible, circulating that under the floor of the raised house
RS> doesnt really help much. What does help is to have a structure
RS> thats got a very low thermal inertia and mount it high, then
RS> it does follow the ambient down overnight reasonably well.

KR> the only passive way that i know of to lower the internal
KR> temperature below that of the ambient air, is to use the
KR> north african technique, of tall towers to get a chimney
KR> effect and draw the air in through courtyards with fountains.

It really isnt that viable, primarily because a courtyard with
fountains doesnt actually reduce the temperature of the ambient
air that much. Yes, its better than nothing, BUT when you have
the modern alternatives, its pretty poor. And it has sweep fuck
all to do with the question of how highsets work, they dont have
that chimney effect, let alone a courtyard with fountains.

KR> kind of a natural swamp cooler.

Not really, you just dont get enough water evaporated into the ambient
air to get anything like the effect you get with a modern system. Sure,
its better than nothing, but nothing like a modern alternative.

KR> works well in dry heat,

And even this graphically illustrates the problem with those older
passive approaches. In the parts of Aust where you do have that dry
heat the modern approach is an evaporative air cooler which does a
HELL of a lot better job using that basic approach. It draws the ambient
thru wet pads, fan driven, move lots of air thru with the fan, you get
a very substantial drop in the temperature of the ambient air. It leaves
the passive approach for dead. And isnt even very expensive to run.

KR> but probably too expensive for here.

Its not that expensive, no more expensive than a pool for
example. But a proper evaporative air cooling system is FAR
better, far cheaper too. Classic example of the old passive
stuff being not that viable when you have a modern alternative.

KR> in the humid north, there is little that you can
KR> do except to catch every possible breeze, as you
KR> say, to drop the thermal inertia as low as possible,

You've mangled that. The primary way to reduce the thermal inertia is
the construction, rather lightweight materials, classic highset approach,
particularly with the air flow thru that level of the house. THEN you
put it up high to get the best advantage of what breeze there is.

BUT, the main advantage of that approach is at night, when it does
do a reasonably job of having the temperature inside the top floor
as close to the ambient as possible. Does fuck all for afternoon
peak temp problem tho. In fact in that respect is rather worse than
a high thermal inertia place, closed up early in the day. That will
see the internal temp lag the external substantially during the day.
But then you have a problem with the high thermal inertial not allowing
it to track the ambient outside during the night very well, even when
you open it up in the evening.

So you would normally want some modern assistance, and once you
add that the highset approach has some very real problems because
of its intrinsic approach of not much thermal resistance between in
the ambient temp and the inside temp. Thats the last thing you want
with modern air conditioning. It just increases your running costs.

KR> and maximise the radiating surfaces to drop the temp as fast as
KR> possible when the sun goes down.

Thats not how highsets work. They work by allowing lots of air movement
thru the top story and they have a rather low thermal inertial. In fact
they normally arent that good radiating surfaces, usually having timber
or fibro walls. They work by being very open, so they follow the ambient
well, particularly because of their low thermal inertial.

KR> in woomera, the heirarchy all had high status brick houses,
KR> and the unwashed masses had fibro, it was a great leveler
KR> to think of your boss sweltering in his sweatbox mansion
KR> when, an hour after dark the fibro shack was quite livable.

Thats crap Keef. You have the same mix of houses here. With proper
modern airconditioning, either air coolers or full airconditioning,
it works completely differently. And there are almost no houses
without one or the other now. Or any other buildings for that matter.

The brick construction works very well because you turn the cooling
on quite early in the day, many turning it on at breakfast. That them
maintains the temperature in the house at what you want thru the day.
In the hottest weather that would go right thru the night too with
most of the houses. The running costs arent a problem with evap coolers.

The fibro houses are a real problem. Their thermal resistance is much
worse during the day so its usually not that easy to actually maintain
an acceptible temperature during the day even with decent cooling.

And your cool down at night just doesnt arise if you have been
cooling it with modern air cooling during the day. Which everyone
does if they are actually occupying the house during the day.

Even if you dont occupy the house during the day, the fibro houses
dont work that well. They are a fucking inferno when you get home,
say 5-6pmish. With daylight saving the temp wont necessarily be
acceptible even at 10pm. The brick house works a lot better, you

(Continued to next message)

--- PQWK202