Lights Out In 2009?

[Gurm]

I find it kind of hilarious, that's all.

You can't possibly conceive that AC might be necessary in order to live in tropical climates? I have Finnish blood. My body is evolved to live someplace where 80'F is a VERY hot day. Not someplace where it never drops below 80'F from mid-May through mid-September!

So by your argument, I should just give in to my genetic programming, and go northward. Probably to Newfoundland. Great plan. Let's get everyone with dark skin to go to South Carolina, and the rest of us can go live in the North.

Oh wait, and burn coal to stay warm. Or use JUST AS MUCH ELECTRICITY on heat as we do on AC.

What a good plan.

[Brian Ellis]

I cant really see building to conserve heat much different from building to conserve cold. Its all a matter of isolation, airflow considerations and behaviour changes.

Wrong, wrong and wrong. Hot air rises, cold air descends. That is one basic precept. I live in a modern hot climate house with high ceilings and no basement or sanitary space, so the tile-on-concrete floor, without insulation, is sitting directly on the ground so that it is cool in summer. It has double-glazing but, unfortunately, minimal insulation. In winter, it is hell to heat because all the hot air rises out of reach.

Our typical aircon use in, say, 40°C weather is usually none during the day, except possibly in my office, which is a 12 m² room with up to 3 computers working. I switch it on if the temp reaches 33°C, as much for the computers' sake as mine. It is only in the evening when the temp starts to drop and the humidity rises that we have it on for a couple of hours in the living room. We have it on in the bedroom for only one hour before going to bed. All the aircons are set for 26-28°C, so they hardly drop the temp in the evening but they do dehumidify the rooms and make them less friendly for no-see-ums and other biting insects. Our electricity consumption in summer is typically only about 10% higher than in spring or autumn when we have neither heating nor cooling.

I used to live in a very old (~400 years) cold-weather house in Switzerland with low ceilings, cellar, insulated wooden floor, tiny windows, very thick walls. It was murder in hot, humid weather.

And the 2nd law of thermodynamics states that you cannot conserve cold: you may prevent heat from flowing in, but you can't have cold flowing out; it doesn't happen.

[rylan]

Yeah its really about modern housing design since AC has become common. Houses and building used to be made to channel airflow naturally and take advantage of ambient air flows. Now with high density cities and offices, AC is required. Add to that high tech devices and there is even more heat load.

[Tjalfe]

I guess nobody should live in Toronto either.. easily +35C in summer and -35C in winter

[Gurm]

I guess nobody should live in Toronto either.. easily +35C in summer and -35C in winter

We should all become nomadic, migrating south for the winter and north for the summer. That's how we can save the planet, didn't you know?

[Brian Ellis]

Covered wagons or SUV's as the means of locomotion?

[Jammrock]

Covered wagons or SUV's as the means of locomotion?

SUVs will release large amounts of CO2/CO, while the amount of oxen and horses needed to move several hundred million people would generate massive amounts of methane. We're screwed either way.


Kind of off the topic, I was out walking the dog this morning and took a look at my roof and noticed there are some good spots that get light from sunrise to sunset. If I could get 1 kW of solar cells installed for well under $10k I would consider making the investment, but the price per watt just isn't there yet.

[DukeP]

Brian, both the heath and the cold is comming from the outside.

To protect against heat, You insulate your outer surfaces, so you get a temperature gradient.

Although modern windows might be a problem (one-way heat retaining glasscoatings doesnt keep the hot summer out) - it ought to be surmountable.

And 400 mm of rockwool is a great way to insulate against both cold and heat (minimum legal insulationdepth in Denmark).

The ground is always at 5-7 degress celcious, so if one needs cooling, dig in. As to moving air around, heat-exchanging ventilation systems exists that uses very little power and has got a very high efficency.

~~DukeP~~

[Gurm]

As to moving air around, heat-exchanging ventilation systems exists that uses very little power and has got a very high efficency.

~~DukeP~~

And costs more than the average American family makes in a year.

[Brian Ellis]

400 mm???? That would reduce the habitable are of a 10 x 10 m plan by 16%. It's enormous!!!

[DukeP]

Yeah Brian, it is quite beastly - especially if Youve got A type houses - the roof insulation dramatically reduces the amount of loft space.

Further - all newly constructed houses has to be pressure tested. They are required to be soo well isolated, that newly constructed chimneys have a dual channel system - a seperate channel as air INTAKE - the houses are far too tight to get a proper burn (unless You keep a window open, and that kind of defeats the purpose).

As for Gurm - I think you drastically underestimate the amount of cash the average american earn! Compared to You, we are all paupers, over here.

A nice, 500 sqmeter/h system would cost around 10.000$ installed - less if configured and installed as part of a new house.

~~DukeP~~

[Jammrock]

As for Gurm - I think you drastically underestimate the amount of cash the average american earn! Compared to You, we are all paupers, over here.

It only seems that way because because we don't pay 55% taxes.

[VJ]

Well, here in Belgium, AC still is far from standard in houses. But over the last two decades, summers have gotten warmer (with more and longer heatwaves - defined here as 5 consequetive days above 25°C of which 3 above 30°C).
I live in a modern appartment building in the city. The building is concrete, which keeps in heat incredibly well; my only outer wall is my front wall (which isn't too big) and it has two south-west facing windows. The result of all this is that in winter, I don't need much heating; but in summer the building is a disaster: indoor temperatures of 35°C and more are no exception, even in a mild summer. An AC unit is imperative in that appartment... (I have a mobile unit, and it manages to get the temparature down to 28°C, and adds a more comfortable feel to it)

A few years ago, we suffered a huge amount of powerfailures in the city, and this was in the period Februari-April (over 30 power outages in 3 months). They power company then admitted that the network was partly outdated and made huge investments: we haven't had a power outage since...
(I think it is the same story everywhere: things have to happen before investments are made)

Jörg

[Gurm]

As for Gurm - I think you drastically underestimate the amount of cash the average american earn! Compared to You, we are all paupers, over here.

Let's not get onto THAT discussion. The "median family income" in the USA is still something like 48,000 USD. After taxes that's more like $30k.

[Tjalfe]

400 mm???? That would reduce the habitable are of a 10 x 10 m plan by 16%. It's enormous!!!

I am pretty sure that is attic insulation only.. there is no way the walls are that thick in Denmark. The new construction I have seen there was mostly prefabricated wall sections of gas concrete, or whatever the term is, think Concrete with lots of air bubbles, then an outer shell of brick.
Here in New construction you need R19 in the walls, which is usually 1" of Extruded foam on the outside of the house, then R14 batt insulation in the stud space in the walls. R40 in the attic, but more and more are going R50 or even R60

Our main use of the air conditioner is not as much to cool as it is to dehumidify. Summers in Toronto can be worse than walking around in the amazon.