Modern homes trapping heat ‘like a plastic bag’
In a country where capital city temperatures regularly exceed 35 degrees Celsius and even 40C in some states, it could be expected that modern houses are already built to resist heat.
more…
Tau.Neutrino said:
Modern homes trapping heat ‘like a plastic bag’In a country where capital city temperatures regularly exceed 35 degrees Celsius and even 40C in some states, it could be expected that modern houses are already built to resist heat.
more…
Do plastic bags trap heat well?
Tau.Neutrino said:
Modern homes trapping heat ‘like a plastic bag’In a country where capital city temperatures regularly exceed 35 degrees Celsius and even 40C in some states, it could be expected that modern houses are already built to resist heat.
more…
I work in an Edwardian-era building. high ceilings, wide verandahs upstairs and down, ceiling fans, high peaked roof, lots of big sash windows (big enough to easily step through, when open).
It’s not perfect, but it sure works as well as you could expect, without a/c.
dv said:
Tau.Neutrino said:
Modern homes trapping heat ‘like a plastic bag’In a country where capital city temperatures regularly exceed 35 degrees Celsius and even 40C in some states, it could be expected that modern houses are already built to resist heat.
more…
Do plastic bags trap heat well?
They function as home made hot air balloons fairly well, so, yes…
Most certainly aren’t designed to be temperature friendly
poikilotherm said:
dv said:
Tau.Neutrino said:
Modern homes trapping heat ‘like a plastic bag’In a country where capital city temperatures regularly exceed 35 degrees Celsius and even 40C in some states, it could be expected that modern houses are already built to resist heat.
more…
Do plastic bags trap heat well?
They function as home made hot air balloons fairly well, so, yes…
A fair rejoinder
I’ve seen house around here, with no eaves – built right to the roof edge.
Not only do they look silly/ugly, you’re giving away absolutely any chance of shading the windows.
As i sit here, our modest eaves are doing a good job of providing just that kind of shade.
captain_spalding said:
Tau.Neutrino said:
Modern homes trapping heat ‘like a plastic bag’In a country where capital city temperatures regularly exceed 35 degrees Celsius and even 40C in some states, it could be expected that modern houses are already built to resist heat.
more…
I work in an Edwardian-era building. high ceilings, wide verandahs upstairs and down, ceiling fans, high peaked roof, lots of big sash windows (big enough to easily step through, when open).
It’s not perfect, but it sure works as well as you could expect, without a/c.
My house..
Built 1920, sandstone with tin roof.
High ceilings, big windows, no aircon or fans
inside 24.8
outside 37.4
As the summers pass you get to learn more and more, your knowledge bank and the wisdom of how to use it grows.
10 or so years ago I didn’t know Fujitsu was Australia’s favourite air.
captain_spalding said:
I’ve seen house around here, with no eaves – built right to the roof edge.Not only do they look silly/ugly, you’re giving away absolutely any chance of shading the windows.
As i sit here, our modest eaves are doing a good job of providing just that kind of shade.
Yeah horrible aren’t they stack people right next to each other.
Peak Warming Man said:
As the summers pass you get to learn more and more, your knowledge bank and the wisdom of how to use it grows.
10 or so years ago I didn’t know Fujitsu was Australia’s favourite air.
Peak Warming Man said:
Yeah, but I believe Tubby. He would never mislead people for filthy lucre. No sir, he wouldn’t do that for moolah. Never.
As the summers pass you get to learn more and more, your knowledge bank and the wisdom of how to use it grows.
10 or so years ago I didn’t know Fujitsu was Australia’s favourite air.
I can’t find the article which I only read the other day but it mentions how the standard temperature air conditioners are set at was based on middle aged men comfort levels from decades ago. It also mention that Australian spend something like a billion and half dollars using air conditioners unnecessary
Sean Marsh is Australia’s favourite heir
dv said:
Sean Marsh is Australia’s favourite heir
Mark Waugh is Australia’s favourite spare…
Greg Matthews had Australia’s favourite yeah
Cymek said:
I can’t find the article which I only read the other day but it mentions how the standard temperature air conditioners are set at was based on middle aged men comfort levels from decades ago. It also mention that Australian spend something like a billion and half dollars using air conditioners unnecessary
my house (despite the fact that on one side there are no eaves) stays fairly cool in summer. I rarely have to use the air con. Most mornings and breezier evenings, we open the cross windows and it cools the house down enough to last for the day.
A friend of mine has his aircon (the same as mine) on 24/7 year around. He keeps it at 22 deg which he says is ideal. Though I haven’t asked him about his electricity bill..
dv said:
Greg Matthews had Australia’s favourite yeah
Mike Whitney showed Australia’s biggest dare…
Winks is Australia’s favourite mare.
DV is Australia’s favourite person who posts in incorrect threads, so there
Arts said:
DV is Australia’s favourite person who posts in incorrect threads, so there
That’s very flattering.
dv said:
Arts said:
DV is Australia’s favourite person who posts in incorrect threads, so there
That’s very flattering.
well, I didn’t take a poll or anything… but let’s assume for now
dv said:
Arts said:
DV is Australia’s favourite person who posts in incorrect threads, so there
That’s very flattering.
Shame it’s restricted to the group of people who post in incorrect threads, but that’s a pretty big group I imagine, so it’s still pretty flattering I suppose.
:)
informative, a lovely educational indulgence, good-intentioned, unlikely to offend, that article.
part of insulation is to lock out sound, and trap it inside, so you can’t hear the neighbors kids, cars pulling up, or next doors having sex on a still night, or them hear you, or the rain on the roof, or the wind, or others TVs, the list is quite long.
in this context, lots of insulation and having things shut up, windows and doors etc, well, the need for climate control extends way past when the external temperature comes down to something that’d be otherwise comfortable.
there are things called trees too, but people mostly prefer concrete, or whatever, but you know high-density living, $$$ and all that, fuck trees they’re a bit, well, they hardly speak the language.
The Rev Dodgson said:
dv said:
Arts said:
DV is Australia’s favourite person who posts in incorrect threads, so there
That’s very flattering.
Shame it’s restricted to the group of people who post in incorrect threads, but that’s a pretty big group I imagine, so it’s still pretty flattering I suppose.
I take what I can get
Note, though, that I didn’t post in the wrong thread in this case
dv said:
The Rev Dodgson said:
dv said:That’s very flattering.
Shame it’s restricted to the group of people who post in incorrect threads, but that’s a pretty big group I imagine, so it’s still pretty flattering I suppose.
I take what I can get
klepto…
Cymek said:
I can’t find the article which I only read the other day but it mentions how the standard temperature air conditioners are set at was based on middle aged men comfort levels from decades ago. It also mention that Australian spend something like a billion and half dollars using air conditioners unnecessary
Heat rises, heat collects under the ceiling, so it make sense to use exhaust fans in the ceiling to extract the heat and vent it outside.
This is what I do here, I turn on the kitchen and bathroom exhaust fans on, on really hot evenings, cools down the place at night.
Ive installed ceiling fans and exhaust fans that have side vents that have auto off, when off it shuts the flaps inside them, to stop drafts in winter.
I’m going to put one in the lounge room, and later look at better ceiling insulation and an outside blind.
Having a back south door facing the northern front door makes for cool drafts as well, when there is a south wind that is.
Tau.Neutrino said:
Cymek said:
I can’t find the article which I only read the other day but it mentions how the standard temperature air conditioners are set at was based on middle aged men comfort levels from decades ago. It also mention that Australian spend something like a billion and half dollars using air conditioners unnecessary
Heat rises, heat collects under the ceiling, so it make sense to use exhaust fans in the ceiling to extract the heat and vent it outside.
This is what I do here, I turn on the kitchen and bathroom exhaust fans on, on really hot evenings, cools down the place at night.
Ive installed ceiling fans and exhaust fans that have side vents that have auto off, when off it shuts the flaps inside them, to stop drafts in winter.
I’m going to put one in the lounge room, and later look at better ceiling insulation and an outside blind.
Having a back south door facing the northern front door makes for cool drafts as well, when there is a south wind that is.
Having the exhaust fans connected to an inside outside temperature sensor could help, the exhaust fan could be programmed to come on and switch off under certain conditions.
Then you are constantly cooling more air. We use the ceiling fans to mix the air. Close off the rooms we are not using. Then cool down the air in the ones we are using.
buffy said:
Then you are constantly cooling more air. We use the ceiling fans to mix the air. Close off the rooms we are not using. Then cool down the air in the ones we are using.
I use the ceiling fans during the day; they are reversible, during the evening I turn off the ceiling fans then turn on the exhaust fans when opening the house when its cool. if the reversible feature was electronic I’d use it more often.
We’ve never bothered to reverse the fans. It doesn’t matter if they are fanning down or fanning up. If they fan up, the air just bounces down off the ceiling anyway. You are aiming for mixing anyway.
Tau.Neutrino said:
buffy said:Then you are constantly cooling more air. We use the ceiling fans to mix the air. Close off the rooms we are not using. Then cool down the air in the ones we are using.
I use the ceiling fans during the day; they are reversible, during the evening I turn off the ceiling fans then turn on the exhaust fans when opening the house when its cool. if the reversible feature was electronic I’d use it more often.
You could build an arduino thingie to control the switching on of exhaust fans at night, also switch the ceiling fans from blowing down air to sucking up air.
That could reduce air conditioning time by a significant amount.
buffy said:
We’ve never bothered to reverse the fans. It doesn’t matter if they are fanning down or fanning up. If they fan up, the air just bounces down off the ceiling anyway. You are aiming for mixing anyway.
Yes which leads to a very good question, which angle of ceiling is ideal for fans sucking up air and directing it to a central exhaust point.
Tau.Neutrino said:
buffy said:We’ve never bothered to reverse the fans. It doesn’t matter if they are fanning down or fanning up. If they fan up, the air just bounces down off the ceiling anyway. You are aiming for mixing anyway.
Yes which leads to a very good question, which angle of ceiling is ideal for fans sucking up air and directing it to a central exhaust point.
Also what type of ceiling surface design could direct air up and away from being blown back.
Would multiple exhaust points be better?
Tau.Neutrino said:
Tau.Neutrino said:
buffy said:We’ve never bothered to reverse the fans. It doesn’t matter if they are fanning down or fanning up. If they fan up, the air just bounces down off the ceiling anyway. You are aiming for mixing anyway.
Yes which leads to a very good question, which angle of ceiling is ideal for fans sucking up air and directing it to a central exhaust point.
Also what type of ceiling surface design could direct air up and away from being blown back.
Would multiple exhaust points be better?
You would be hot in your caravan at the moment.
I don’t understand why you are wanting to exhaust. Surely it’s better to do as you do in your car….use the same internal air, cool it, and keep it cool. If you exhaust your air you must continue to cool. Has to use more energy.
buffy said:
I don’t understand why you are wanting to exhaust. Surely it’s better to do as you do in your car….use the same internal air, cool it, and keep it cool. If you exhaust your air you must continue to cool. Has to use more energy.
Yes, the cool air has to come from somewhere. I do the opposite and it works well, this place stays very cool in summer. Hot days it’s close everything down, even the rooms, doors are closed. I don’t want heat from a room against a wall transferring to the central corridor. All the curtains are drawn except for the one in the lounge which is under the verandah and only half opened for a bit of light.
House is a big box full of cool internal walls and cool air, idea is to keep it all in.
Tau.Neutrino said:
Modern homes trapping heat ‘like a plastic bag’In a country where capital city temperatures regularly exceed 35 degrees Celsius and even 40C in some states, it could be expected that modern houses are already built to resist heat.
more…
I was working with CSIRO on that. The technique being used by CSIRO was quite different to the British/American one of double and triple glazed windows filled with nitrogen or neon. The CSIRO approach was to use the air gap between outer wall/roof and inner cladding/ceiling to conduct heat up and away from the building. With or without evaporative cooling.
The worst possible combination is low galvanised iron roof with no ceiling – the galvanised iron roof gets very very hot on sunny days.
AwesomeO said:
buffy said:I don’t understand why you are wanting to exhaust. Surely it’s better to do as you do in your car….use the same internal air, cool it, and keep it cool. If you exhaust your air you must continue to cool. Has to use more energy.
Yes, the cool air has to come from somewhere. I do the opposite and it works well, this place stays very cool in summer. Hot days it’s close everything down, even the rooms, doors are closed. I don’t want heat from a room against a wall transferring to the central corridor. All the curtains are drawn except for the one in the lounge which is under the verandah and only half opened for a bit of light.
House is a big box full of cool internal walls and cool air, idea is to keep it all in.
Hot air rises so in summer so using the exhaust complements the natural process of bringing in cool air which expels the warmer air from the top of the house where it is hottest, using solar energy and/or batteries to power the fans complements this again.
Hot air rises so hot air will collect under the ceiling, expelling it, seems the logical thing to do. Exhaust fans can do this very well.
The opposite in winter is having a mezzanine floor above when heating below will make the hot air rise and make the mezzanine area cozy.
Tau.Neutrino said:
AwesomeO said:
buffy said:I don’t understand why you are wanting to exhaust. Surely it’s better to do as you do in your car….use the same internal air, cool it, and keep it cool. If you exhaust your air you must continue to cool. Has to use more energy.
Yes, the cool air has to come from somewhere. I do the opposite and it works well, this place stays very cool in summer. Hot days it’s close everything down, even the rooms, doors are closed. I don’t want heat from a room against a wall transferring to the central corridor. All the curtains are drawn except for the one in the lounge which is under the verandah and only half opened for a bit of light.
House is a big box full of cool internal walls and cool air, idea is to keep it all in.
Hot air rises so in summer so using the exhaust complements the natural process of bringing in cool air which expels the warmer air from the top of the house where it is hottest, using solar energy and/or batteries to power the fans complements this again.
Hot air rises so hot air will collect under the ceiling, expelling it, seems the logical thing to do. Exhaust fans can do this very well.
The opposite in winter is having a mezzanine floor above when heating below will make the hot air rise and make the mezzanine area cozy.
Hot air rises in summer so using the exhaust complements the natural process of bringing in cool air which expels the warmer air from the top of the house where it is hottest, using solar energy and/or batteries to power the fans complements this again.
Tau.Neutrino said:
AwesomeO said:
buffy said:I don’t understand why you are wanting to exhaust. Surely it’s better to do as you do in your car….use the same internal air, cool it, and keep it cool. If you exhaust your air you must continue to cool. Has to use more energy.
Yes, the cool air has to come from somewhere. I do the opposite and it works well, this place stays very cool in summer. Hot days it’s close everything down, even the rooms, doors are closed. I don’t want heat from a room against a wall transferring to the central corridor. All the curtains are drawn except for the one in the lounge which is under the verandah and only half opened for a bit of light.
House is a big box full of cool internal walls and cool air, idea is to keep it all in.
Hot air rises so in summer so using the exhaust complements the natural process of bringing in cool air which expels the warmer air from the top of the house where it is hottest, using solar energy and/or batteries to power the fans complements this again.
Hot air rises so hot air will collect under the ceiling, expelling it, seems the logical thing to do. Exhaust fans can do this very well.
If I open the door on a hot day, it’s hotter outside than inside. If I get rid of my cool air what do I replace it with?
Tau.Neutrino said:
Tau.Neutrino said:
AwesomeO said:Yes, the cool air has to come from somewhere. I do the opposite and it works well, this place stays very cool in summer. Hot days it’s close everything down, even the rooms, doors are closed. I don’t want heat from a room against a wall transferring to the central corridor. All the curtains are drawn except for the one in the lounge which is under the verandah and only half opened for a bit of light.
House is a big box full of cool internal walls and cool air, idea is to keep it all in.
Hot air rises so in summer so using the exhaust complements the natural process of bringing in cool air which expels the warmer air from the top of the house where it is hottest, using solar energy and/or batteries to power the fans complements this again.
Hot air rises so hot air will collect under the ceiling, expelling it, seems the logical thing to do. Exhaust fans can do this very well.
The opposite in winter is having a mezzanine floor above when heating below will make the hot air rise and make the mezzanine area cozy.
Hot air rises in summer so using the exhaust complements the natural process of bringing in cool air which expels the warmer air from the top of the house where it is hottest, using solar energy and/or batteries to power the fans complements this again.
Sorry.
Hot air rises all the time.
but you get the idea
AwesomeO said:
Tau.Neutrino said:
AwesomeO said:Yes, the cool air has to come from somewhere. I do the opposite and it works well, this place stays very cool in summer. Hot days it’s close everything down, even the rooms, doors are closed. I don’t want heat from a room against a wall transferring to the central corridor. All the curtains are drawn except for the one in the lounge which is under the verandah and only half opened for a bit of light.
House is a big box full of cool internal walls and cool air, idea is to keep it all in.
Hot air rises so in summer so using the exhaust complements the natural process of bringing in cool air which expels the warmer air from the top of the house where it is hottest, using solar energy and/or batteries to power the fans complements this again.
Hot air rises so hot air will collect under the ceiling, expelling it, seems the logical thing to do. Exhaust fans can do this very well.
If I open the door on a hot day, it’s hotter outside than inside. If I get rid of my cool air what do I replace it with?
The idea is to use it at night when its cooler or when a cool change comes in
if its 32 during the day you wouldn’t use it
get it?
AwesomeO said:
Tau.Neutrino said:
AwesomeO said:Yes, the cool air has to come from somewhere. I do the opposite and it works well, this place stays very cool in summer. Hot days it’s close everything down, even the rooms, doors are closed. I don’t want heat from a room against a wall transferring to the central corridor. All the curtains are drawn except for the one in the lounge which is under the verandah and only half opened for a bit of light.
House is a big box full of cool internal walls and cool air, idea is to keep it all in.
Hot air rises so in summer so using the exhaust complements the natural process of bringing in cool air which expels the warmer air from the top of the house where it is hottest, using solar energy and/or batteries to power the fans complements this again.
Hot air rises so hot air will collect under the ceiling, expelling it, seems the logical thing to do. Exhaust fans can do this very well.
If I open the door on a hot day, it’s hotter outside than inside. If I get rid of my cool air what do I replace it with?
This. What Tau seems to be talking about is the overnight cooling part of the system. We don’t use the aircon at night, mostly. We have the exhausts open now…front and back doors and all windows open. The cool air is moving through the house. We will trap as much as possible overnight and then close it in in the morning.
Tau.Neutrino said:
AwesomeO said:
Tau.Neutrino said:Hot air rises so in summer so using the exhaust complements the natural process of bringing in cool air which expels the warmer air from the top of the house where it is hottest, using solar energy and/or batteries to power the fans complements this again.
Hot air rises so hot air will collect under the ceiling, expelling it, seems the logical thing to do. Exhaust fans can do this very well.
If I open the door on a hot day, it’s hotter outside than inside. If I get rid of my cool air what do I replace it with?
The idea is to use it at night when its cooler or when a cool change comes in
if its 32 during the day you wouldn’t use it
get it?
But you seem to have been talking about general daytime stuff.
Tau.Neutrino said:
Tau.Neutrino said:
Tau.Neutrino said:Hot air rises so in summer so using the exhaust complements the natural process of bringing in cool air which expels the warmer air from the top of the house where it is hottest, using solar energy and/or batteries to power the fans complements this again.
Hot air rises so hot air will collect under the ceiling, expelling it, seems the logical thing to do. Exhaust fans can do this very well.
The opposite in winter is having a mezzanine floor above when heating below will make the hot air rise and make the mezzanine area cozy.
Hot air rises in summer so using the exhaust complements the natural process of bringing in cool air which expels the warmer air from the top of the house where it is hottest, using solar energy and/or batteries to power the fans complements this again.
Sorry.
Hot air rises all the time.
but you get the idea
Not really, you keep saying bring in cooler air. Out here in summer it gets to 38 plus. Low 40s expected on Saturday. The sky is blue and everything is enervated, even the colour is washed out, back paddocks disappear in a shimmer of heat. Where is this cool air coming from?
AwesomeO said:
Tau.Neutrino said:
Tau.Neutrino said:Hot air rises in summer so using the exhaust complements the natural process of bringing in cool air which expels the warmer air from the top of the house where it is hottest, using solar energy and/or batteries to power the fans complements this again.
Sorry.
Hot air rises all the time.
but you get the idea
Not really, you keep saying bring in cooler air. Out here in summer it gets to 38 plus. Low 40s expected on Saturday. The sky is blue and everything is enervated, even the colour is washed out, back paddocks disappear in a shimmer of heat. Where is this cool air coming from?
I have a whirly thing on my roof. The theory being that the trapped air in the roof can heat up to over 50 C on a hot day. Venting that air and replacing it with fresh air at the ambient 38 or 40 C is technically bringing in cooler air.
https://www.bunnings.com.au/our-range/building-hardware/building-construction/ventilation/roof
Whirlybirds can be used to help remove the heat from the ceiling space.
was reading something about those roof fans the other day.
ChrispenEvan said:
was reading something about those roof fans the other day.
http://efficiencymatrix.com.au/does-roof-ventilation-work/
I like the Persian wind tower idea.
party_pants said:
I like the Persian wind tower idea.
party_pants said:
I like the Persian wind tower idea.
Persian or maybe Arabian architecture also uses a small open courtyard in the middle of the house but with high walls and eaves is in permanent shade.
Stumpy_seahorse said:
party_pants said:
I like the Persian wind tower idea.
it is an evaporative aircon system using no power but the wind. They had the underground tunnels for water supply anyway (slowly built up over centuries). Clever idea.
Australian houses need more cool vaulted cellars and dungeons.
party_pants said:
Stumpy_seahorse said:
party_pants said:
I like the Persian wind tower idea.
it is an evaporative aircon system using no power but the wind. They had the underground tunnels for water supply anyway (slowly built up over centuries). Clever idea.
it’s a clever design.
how do they get the hot air to descend and the cool air to rise? tunnel orientation or something?
Stumpy_seahorse said:
party_pants said:
Stumpy_seahorse said:
it is an evaporative aircon system using no power but the wind. They had the underground tunnels for water supply anyway (slowly built up over centuries). Clever idea.
it’s a clever design.
how do they get the hot air to descend and the cool air to rise? tunnel orientation or something?
the coanda effect.
http://www.solaripedia.com/13/205/2093/wind_tower_diagram.html
Stumpy_seahorse said:
party_pants said:
Stumpy_seahorse said:,
it is an evaporative aircon system using no power but the wind. They had the underground tunnels for water supply anyway (slowly built up over centuries). Clever idea.
it’s a clever design.
how do they get the hot air to descend and the cool air to rise? tunnel orientation or something?
The shuttewrs on the tower are only opened on the side facing away from the wind. The wind going around the tower creates eddies that “suck” air out of the vent. If the building is well sealed then fresh air can only be drawn in from the water tunnel.
party_pants said:
Stumpy_seahorse said:
party_pants said:it is an evaporative aircon system using no power but the wind. They had the underground tunnels for water supply anyway (slowly built up over centuries). Clever idea.
it’s a clever design.
how do they get the hot air to descend and the cool air to rise? tunnel orientation or something?
The shuttewrs on the tower are only opened on the side facing away from the wind. The wind going around the tower creates eddies that “suck” air out of the vent. If the building is well sealed then fresh air can only be drawn in from the water tunnel.
cool, thanks
my take on it is don’t worry with breeze, ventilation etc
put a whacking big solar system above the roof and run two 5kw air con all day
they don’t know how to buiold houses here anyway, have all the fancy designs you want, the labour putting it all together is crap.
the characters that put my house fed the consumer mains (the electric wire from the pole to the switchboard) under the hanging beams and the gyprock of the ceiling
they cut the earth wires meant to connect to the metallic parts of lights in the house
when i changed my hot water system i discovered the cable to the hot water system stretched like piano wire across the ceiling, the new tank couldn’t be shifted around so i had to rerun a new length from the roof space to the tank (intelligent people put a few loops of spare cable on the length to allow for this)
from my dealings where i inspected many building here not one was wired to the australian standards EVER, even from new. in QLD doesn’t even inspect new installations (only if someone gets killed or injured)
In yesterday’s Age an article about one of the reasons why the recent power cuts in Melbourne. I had mentioned before how devices were more energy efficient these days and power demands had stayed fairly static despite a glowing population.
The article pointed to a confounding variable and one which sounds exactly right, in Melbourne entire suburbs, back to back of McMansions that in hot weather run air conditioning day and night to cool acres of internal open plan space.
It’s an obvious problem when you think about it.
AwesomeO said:
In yesterday’s Age an article about one of the reasons why the recent power cuts in Melbourne. I had mentioned before how devices were more energy efficient these days and power demands had stayed fairly static despite a glowing population.The article pointed to a confounding variable and one which sounds exactly right, in Melbourne entire suburbs, back to back of McMansions that in hot weather run air conditioning day and night to cool acres of internal open plan space.
It’s an obvious problem when you think about it.
Yes. That’s one of three problems I think of every time I see open plan space houses in Melbourne. The other two are – shockingly loud (no sound proofing) – and no curtains.
