Energy efficient building

[supa007]

I'm planning a massive renovation/extension on a 1920's solid brick house. To reducing our energy expenditure /carbon emission / running cost, I'm planning to build with insulated concrete forms (ICF) for its superior insulating properties. This will go on concrete slab for the thermal mass effect. We'll have large north facing windows, as well as all windows being double glazed. Also will have actively vented roof space during summer which can be closed for winter, plus proper roof insulation with batt and foil.

Are there any other building ideas out there to improve energy efficiency of the building?

Also, can anyone shed light on whether reverse cycle A/C is any good at heating, compared with conventional gas heaters in terms of efficiency and cost of running.

Any input appreciated, thanks.

Kevin

[OBBob]

Hi There ... I love this stuff but have found it hard enough to build my place conventionally let alone incude much more 'green' factor than good insulation and north facing windows.

What a botu solar power, solar water heating and if you want to really get experimental ... solar air heating? eg. try this link, just an example ... there are plenty of products / designs of this nature around .
http://www.solar-components.com/SOLARKAL.HTM

And these sites for some other info?

http://www.sustainablebuildings.com.au/

http://www.greenhouse.gov.au/yourhom...nical/fs30.htm


I think the AC would be an expensive way of heating compared to gas.

[pharmaboy2]

reverse cycle air is very effcient per energy in - you can get a 3.5 * improvement so 1000w of electricity produces 3500w of heating, so uses up less fossil fuels than gas heating, though I think gas would still have a co2 advantage, despite its lack of effciency.

make sure your eaves are the right length for your latitude - eg sydney is typically 1.0m eaves for north for a 2.1 window, and window set 300mm lower than eave from memory *(for true north). Its amazing how many houses make the effort to get the right orinetation then allow way to much heat gain in summer through insufficient shading.

cost of running, ac is about the same as gas - as always it depends on how you are paying for your electricity, for example, I'm on a timer so only pay 5c pkwh at off peak times - so a house with good thermal mass can be heated very cheaply before 7am with reverse cycle ac and then turned off.

with double glazing, you rea;lly need a lot of shading - heat gain will be the same as standard windows. By the sounds of it, your aims will be different than mine - my house is lightwieght, so insulation for heat hold and allowing heat to escape in summer is my aim, whereas with solid brick you are going to be trying to maximise the thermal mass process - cladiing the exterior is also a very effective means, as it is we build buildings the wrong way round - bricks should be on the interior and light weight cladding should be on the exterior - but thats another story entirely!

[woodbe]

with double glazing, you rea;lly need a lot of shading - heat gain will be the same as standard windows.

I agree with you, but just to clarify. The heat gain from direct sunlight hitting the glass will be quite similar for plain glass windows double glazed or not. Treated glass may marginally alter that, but there is really no substitute for shading.

On the other hand, the heat loss/gain by conduction through the glass will be dramatically different. So, if your window is shaded, and you have spent energy dollars making it comfortable inside, it will stay comfortable for longer with double glazing then with single glazing.

The other thing to pay attention to is window and door sealing. There's not much point spending dollars on fancy glass if the first breeze is going to push all your comfortable air out all the cracks around the windows and doors.

A single trip to just about anywhere in the northern hemisphere will convince you just how wrong we have been about energy efficiency in our homes down under. Thankfully the times are changing, and the quality on offer is improving all the time.

woodbe.

[bricks]

You can install a louvered atrium in the centre of your house to allow hot air up and out during summer this would use natural forces of convection to move air throughout the house rather than powered circulation.

Also Underfloor heating is remarkably efficient ive heard. If you set it at 22 degrees it also acts as cooling in summer.

[ozwinner]

Have a look here.

Al

[N Moore]

Gday

A friend in Tassie is dealing in vacuum heater tubes for solar hot water.
He has units over built for eg Tassie climates to cope with lower temps.

These units are modular and have option of multi linkups to do swimm pools etc.

Plus can adapt to water radiator type heating inside houses etc.

He now has option also of linking solar purchase to a home mortgage that takes advantage of lower interest rates.

His plan is to allow ordinary families access to cheaper solar systems without high markup costs.

Plus farms and businesses. And schools etc..

He can sell units as kits for DIY installers.

His website is http://www.ultragreensun.com.au/

Nick Perth Tasmania

[Bloss]

Also, can anyone shed light on whether reverse cycle A/C is any good at heating, compared with conventional gas heaters in terms of efficiency and cost of running.


Kevin

If you get the design, siting and construction right you can operate without heating and cooling in Melbourne - without additional cost and no recurrent cost. This is so across Australia in non-alpine/ mountain areas.

At worst you should need only ceiling fans for summer and some supplementary heating for winter - natural gas would be best short term fossil fuel to use, new wood fired heaters using renewable plantation timbers are fine for this too.

Spend some more time with your friend Google start with the sites mentioned above. With energy costs likely to continue increasing it is well worth the input on research and good design now.

Of course the simple things remain important such as not heating your house to more than 18-19 degrees and not cooling below 24-25.

As Billy Connolly once said - "there is no such thing as bad weather, only wrong clothes" and in the home context it is only recently that we have come to imagine that we should be able to wear T-shirts indoors all year round. Future energy saving pressures will demand it, but right now you can save lots of money and be just as comfortable by using technology that was the norm until just a few years ago - such as woollen jumpers worn inside the house in winter.

[Metung]

I couldn't agree with Bloss more. I tried to use all the principles mentioned in the various websites nominated and couldn't be happier with the outcome. We have been in the house 12 months and in that time the temperature has varied between 16-27 degrees (I have a max/min thermometer inside). There is no additional heating or cooling and I suspect there never will be and I'm talking Melbourne latitude. The solar hot water system has had the electric boost turned on for no more than 2 weeks in that time and the lights only need to go on after sundown anywhere in the house. The electricity bill for the last 3 months was $20, excluding supply charge, which accounted for all energy costs. Admittedly the house is only occupied 10 days of every fortnight and there is only me most of the time but I am pretty pleased with that.

I thought there was a limit of 600mm to the width of eaves, at least in Victoria. Is that correct?