On (11 Jul 95) Rod Speed wrote to Keith Richardson...



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,

 RS> before the modern approach was used instead. And I use it extensively

 RS> myself. BUT, in ADDITION to the modern stuff, not instead of.



i put the above sentence through a comprehensibility analyser, and it

said "huh?"



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.



it said the same about this one too.



 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 pas what you find

 RS> acceptible, circulating that under the floor of the raised

 RS> house doesnt really help much. What does help is to have a

 RS> structure thats got a very low thermal inertia and mount it high,

 RS> then it does follow the ambient down overnight reasonably well.



the only passive way that i know of to lower the internal temperature

below that of the ambient air, is to use the north african technique, of

tall towers to get a chimney effect and draw the air in through

courtyards with fountains. kind of a natural swamp cooler. works well in

dry heat, but probably too expensive for here. in the humid north, there

is little that you can do except to catch every possible breeze, as you

say, to drop the thermal inertia as low as possible, and maximise the

radiating surfaces to drop the temp as fast as possible when the sun

goes down. in woomera, the heirarchy all had high status brick houses,

and the unwashed masses had fibro, it was a great leveler to think of

your boss sweltering in his sweatbox mansion when, an hour after dark

the fibro shack was quite livable.



 RS> But does sweet fuck all for the daytime peak. What you want for the

 RS> daytime peak is the reverse, high thermal inertia, minimal heat inflow

 RS> thru the walls and floor and roof so the inside temp lags the outside.



the technique of an insulated and well ventilated roof cavity together

with a wide verandah to shade the walls, and a good flow of air around

and below the house give the best possible passive results. most people

would put up with a higher mid-day peak in order to have cooler evenings

and nights.



KR> down south the opposite is true.



 RS> It aint that simple. And doesnt explain why nothing

 RS> remotely like 50/50 of new houses in Bris are highset.

 RS> And bugger all in the better suburbs with new houses.



highsets are more expensive, and the southern migrants usually but the

bv shit box that they are used to.



BG> Indeed, the further north you go, the less frequently you'll

BG> see lowset houses, presumably for that precise reason.



RS> In the past, sure. Pity we were talking about new houses tho.



BG> In Sydney, Melbourne and Canberra though, I'll agree, most are lowset.



RS> And most new houses in Brisbane are too Bill.



KR> well the el-cheapo shit boxes put up to attract southern migrants are.



 RS> Still bullshit, the bulk of new houses in Bris arent for migrants.



it is predicted that by the turn of the century, the brisbane - gold

coast area, which will probably be one big metropolis by then will be

more populous than melbourne. the locals must be breeding like cats (:



                        Keith



... I'd rather look out from the ppoint than wallow in QWKsand.



--- PPoint 1.92