Just musings without regards to cost (let’s assume a lotto win or a big inheritance or some such)

Seems to me many houses are built first and then air-conditioned later. Let’s build a house from scratch and incorporate air-conditioning into the fundamental design of the place.

I’m thinking mainly of how to cool a house in a hot climate.

My thinking is that the building itself needs to be built as an air-conditioner, using passive energy as much as possible, perhaps augmented by solar and wind.

I like the idea of Persian wind-catchers. A ventilation tower with four or six faces with shutters on each face. Two (or pairs) of towers.

On one tower, the shutters on the side facing away from the wind are opened, creating a suction effect which draws air out of the tower. Since hot air rises, this exhaust ventilation tower should be connected to the top of the building to draw hot air out.

Meanwhile, a second tower opens the shutter facing the wind drawing fresh air in. This air gets directed down underneath the building through a cool basement and enters the building as cool air at ground level – in the original Persian design. I’d like to do something to modify this to col the air directly, either by evaporative cooling, or by some kind of refrigerated cooling using solar power – built into the base of the intake ventilation tower to supply cool air into the building.

My idea of the overall building is some kind of large open warehouse type space, with an insulated roof, and the rooms sort of built inside around in court-yard type layout facing the middle.

Just a few broad ideas – remember cost isn’t an option.

Comments and ideas?

one way would be to simply cover the entire roof with solar panels that would run air con systems rather than waste time trying to catch breeze that may or may not exist

if you go to dubai theres the museum there that mentions the tower idea for cooling

the sustainable house mob have a rule of thumb which says each room should have three ventilation points

you could a fan that suck air from the house out the top – it has to be powerful though – i bought some crappy extractor fan to take out hot air from the room and it didn’t work very well – its noisy and i had a few complaints about it from my significant other

if money if no expense just live near the coast

if you can’t just use solar power to cool the place

i’ve played with the idea of using citric acid to cool a house

you have a tub of citric acid that is dissolved into water – as it does it cools the water. the cool water then cools the rooms as it trickles through heat exchangers

the citric acid and water is then exposed to sunlight, the water evaporates and leaves the crystalline acid ready to be used again

the powdered acid can be used all night to cool a house down

party_pants said:

Comments and ideas?

The coolest part of my yard exercises both heat and shade plus tunnel effect my carport has a west facing wooden fence, a large shady tree, a short flat roofed north/south tunnel and open piers to the east with a west facing solar reflective wall 2.5 metres away.

the quick way is to shade the house using sail

i’ve seen this in hot countries elsewhere and it works

you leave a gap of at least a few feet between sail and roof so ventillation takes away any errant hot air

you could always just have the house as a tower

of a night the occupants retire to the top area to catch the night air

roughbarked said:

party_pants said:

Comments and ideas?

The coolest part of my yard exercises both heat and shade plus tunnel effect.

My carport has a west facing wooden fence, a large shady tree, a short flat roofed north/south tunnel and open piers to the east with a west facing solar reflective wall 2.5 metres away.

the effect is a constant cool breeze.

Just build the house underground.

Or inside the side of a hill.

Either way the earth acts to cool.

tauto said:

Just build the house underground.

Or inside the side of a hill.

Either way the earth acts to cool.

This is why I live in a dugout for part of the year.

constantly 18˚C

tauto said:

Just build the house underground.

Or inside the side of a hill.

Either way the earth acts to cool.

earth normally acts as an insulator

wookiemeister said:

tauto said:

Just build the house underground.

Or inside the side of a hill.

Either way the earth acts to cool.

earth normally acts as an insulator

—-

Yes.

I was responding to keeping cool.

But for heating

The first mammals must have made use of sub surface temps.

tauto said:

wookiemeister said:

tauto said:

Just build the house underground.

Or inside the side of a hill.

Either way the earth acts to cool.

earth normally acts as an insulator

—-

Yes.

I was responding to keeping cool.

But for heating

The first mammals must have made use of sub surface temps.

pretty much we all do

even if we stack up earthenware or sticks or straw

My house, which I designed and built myself, is very cool in summer.

People often comment as to how cool it is on hot days, with no air conditioning.

The house is built on brick piers, so there is good air flow under the floor.

Also I have large trees that overhang the roof and keep it shaded.

We keep blinds closed and ceiling fans on during the hot weather.

Today however will be a good test of it’s coolness as we are forecast to get to 40 degrees. 31 outside at the moment.

The old colonial business buildings were loverly cool places. Built with high ceilings and made from stone and many parts lined with marble.
Some of the old banks in Sydney are good examples.

letting hot air escape out, and letting breezes blow through would go most of the way to cutting down on the need for airconditioning..

Dropbear said:

letting hot air escape out, and letting breezes blow through would go most of the way to cutting down on the need for airconditioning..

Which is why I prefer to be in my carport on hot days.

Hi party_pants.
Do you know the (old ) work of Ken Kern.
His work on sustainable housing and aircon / ventilation was basic but excellent.
My partner made good use of his “The Owner-Built HOme, long ago, and thought the managing of airflow (which I understand to be your interest here) was excellent.

My partner was never, however, a fan of earth covered dwellings .. which I have just discovered, was well founded in KK’s case.

http://en.wikipedia.org/wiki/Solar_chimney

http://energain.co.uk/Energain/en_GB/sales_support/faq.html

What is the maximum temperature, DuPont™ Energain® thermal mass panels can be exposed to?
DuPont™ Energain® should not be exposed to temperature above 40°C. Above 40°C, the material will become soft, and loose part of its rigidity.

I went to look at a house a couple of years ago and it was simply built under a second roof. Imagine a house built underneath a great big carport. Always in the shade.

pommiejohn said:

I went to look at a house a couple of years ago and it was simply built under a second roof. Imagine a house built underneath a great big carport. Always in the shade.

yes

this is what i have seen at a sustainable house open day

the whole house was under a shade and there was about 5 feet distance between house and shade

wookiemeister said:

pommiejohn said:

I went to look at a house a couple of years ago and it was simply built under a second roof. Imagine a house built underneath a great big carport. Always in the shade.

yes

this is what i have seen at a sustainable house open day

the whole house was under a shade and there was about 5 feet distance between house and shade

In the long run it’s not an expensive way to do it either.

I’ll trawl through the interweb and see if I can find a photo if it. Gimme a few minutes.

pommiejohn said:

wookiemeister said:

pommiejohn said:

I went to look at a house a couple of years ago and it was simply built under a second roof. Imagine a house built underneath a great big carport. Always in the shade.

yes

this is what i have seen at a sustainable house open day

the whole house was under a shade and there was about 5 feet distance between house and shade

In the long run it’s not an expensive way to do it either.

I’ll trawl through the interweb and see if I can find a photo if it. Gimme a few minutes.

i have thought seriously about doing it at my place, if the shade was angled you could mount the solar panels on the shade

Here it is. Not much space below the tin roof but enough it seems.

pommiejohn said:

Here it is. Not much space below the tin roof but enough it seems.

probably enough

BUT what about all that heat being radiated down onto the roof of the house by the shade?

if its metal it will do more or less the same thing as the sun, unless its not metal or its insulated enough

you could a different tack

use a large sail instead

wookiemeister said:

pommiejohn said:

Here it is. Not much space below the tin roof but enough it seems.

probably enough

BUT what about all that heat being radiated down onto the roof of the house by the shade?

if its metal it will do more or less the same thing as the sun, unless its not metal or its insulated enough

you could a different tack

use a large sail instead

I can’t remember how much insulation there is. I’m not saying it’s perfect but it’s a step in the right direction.

pommiejohn said:

Here it is. Not much space below the tin roof but enough it seems.

I’ve also seen that houses with a double ceiling are cooler under them.. ie: airspace below roofspace and above inner ceiling.

pommiejohn said:

wookiemeister said:

pommiejohn said:

Here it is. Not much space below the tin roof but enough it seems.

probably enough

BUT what about all that heat being radiated down onto the roof of the house by the shade?

if its metal it will do more or less the same thing as the sun, unless its not metal or its insulated enough

you could a different tack

use a large sail instead

I can’t remember how much insulation there is. I’m not saying it’s perfect but it’s a step in the right direction.

Air is an insulator.

pommiejohn said:

Here it is. Not much space below the tin roof but enough it seems.

Yeah, excellent idea, it does away with the enclosed roof space and replaces it with a breezway, it also increase your tank water catchment area.
Good for tropical climates, the covering awning would need to be self supporting independant from the house and meet the relevant wind ratings so it wouldnt be cheap.

Peak Warming Man said:

Good for tropical climates, the covering awning would need to be self supporting independant from the house and meet the relevant wind ratings so it wouldnt be cheap.

My recollection from talking to the builder was that because it is essentially a commercial warehouse roof without the walls, it wasn’t really too expensive.

Peak Warming Man said:

pommiejohn said:

Here it is. Not much space below the tin roof but enough it seems.

Yeah, excellent idea, it does away with the enclosed roof space and replaces it with a breezway, it also increase your tank water catchment area.
Good for tropical climates, the covering awning would need to be self supporting independant from the house and meet the relevant wind ratings so it wouldnt be cheap.

Nothing is cheap. Though it looks like the owners aren’t short of a quid, it does look like they spend it wisely.

pommiejohn said:

Peak Warming Man said:

Good for tropical climates, the covering awning would need to be self supporting independant from the house and meet the relevant wind ratings so it wouldnt be cheap.

My recollection from talking to the builder was that because it is essentially a commercial warehouse roof without the walls, it wasn’t really too expensive.

Expense is also relevant to savings gained.

pommiejohn said:

Here it is. Not much space below the tin roof but enough it seems.

I like that. I’d have the roof at an angle to promote convection flow and removal of monsoonal rain, but it is a neat design.

Friend of mine dealt with roof insulation by adding a 30mm thick hardwood plank layer to the usual.

Works a treat for the heat as well as the cold.. and a lot less expensive than the above.

There is thousands upon thousands of this type of construction spread across Australia.

>>Friend of mine dealt with roof insulation by adding a 30mm thick hardwood plank layer to the usual.<<

Many of the older weatherboard houses around this area have pine lining boards internally for walls and ceilings. Buggers for painting, but possibly works a little towards insulation too?

The one we had we put pink batts in the ceiling space too though.