Wednesday, December 9, 2009
Tuesday, December 1, 2009
Friday, November 20, 2009
Sunday, October 18, 2009
Wednesday, July 8, 2009
The UK building codes of 2006 introduced mandatory air leakage testing of new houses. Best practice for building air leakage is considered to be between 3 and 7 m3 of air, per hour, per m2 of permeable surafce area at a 50 Pascal (Pa) pressure difference between inside and out. Once a building gets below 3 at 50 Pa, mechanical ventilation is required to maintain indoor air quality. The home featured on Grand Designs achieved an impressive score of just 1.2. To put this into perspective, most houses we test in Canberra are between 15 and 25 at 50 Pa!
Australia is yet to introduce a maximum air leakage standard for new buildings despite it being the most cost effective way to achieve direct energy savings, reduce GHG emissions and improve comfort levels. It is also the simplest and most cost-effective way to retrofit an existing building.
NB: there is a difference between insulation and air leakage. Insulation does not prevent air leakage. Both insulation and air leakage must be addressed to achieve energy efficeincy. Your insulation cannot do its job if your precious heated air can escape directly through holes in the buidling envelope. If you are serious about improving the energy efficiency of your home: 1. seal the air leaks + 2. insulate thoroughly and evenly... 1 + 2 = 3 x more efficient heating in your average Canberra home.
We decided to make a direct comparison and installed a 5W LED in place of one of five 50W halogens in a kitchen. The old halogen globe, light fitting and transformer were quickly and simply removed and the LED was installed directly into the existing hole in the gyprock (sometimes it can be a little trickier depending on the wiring set up).
The result is impressive - the new LED (on the right, above) is very bright and it casts a broader and more even light than the halogens. This kitchen will only need 3-4 LEDs (rather tha 5 halogens) that's a reduction from 250W to 24-32W!
Most impressive was the temperature difference. The lights were switched on at the same time and in less than 5 minutes the halogen was at 98 degrees and the LED was just 16 degrees! The LED is barely visible on the right hand side of the thermal image above. See below for close ups.
The LEDs not only reduce your lighting energy-use and fire risk, but because they are a completely sealed unit they prevent any air leakage (and they can be insulated over because they are so cool), significantly reducing heat loss... and therefore even more energy use!
You can read more about this partiuclar LED here.
Wednesday, June 3, 2009
The Expo, to be held on Friday June 12 and Saturday June 13, will showcase ways that the local community can reduce its impact and the environment.Download a flyer and program of events here.
Friday, April 3, 2009
The original parts of Alex's house are nearly 80 years old and its been extended a couple of times in more recent years. No surprise - we found it to be very leaky. The beautiful old exposed floorboards were particularly sieve-like! The pleasant surprise was how generally well-sealed the windows and surrounding architraves were. Some clear insulation gaps were also spotted.
There is big potential to relatively quickly and inexpensively improve the energy efficiency and comfort level of the home. Having seen (and felt) the extent of the gaps, Alex seems pretty motivated to start plugging them up before Canberra winter hits. Dear old Bessie (the healthy, hot dog with cold nose) will appreciate the reduction in cool drafts too!
Saturday, March 28, 2009
How does it work?
1. Firstly, households need to have a qualified household sustainability assessor investigate their current energy and water use. After participating in a household sustainability assessment the household will be provided with a tailored report on the best water and energy saving changes they can make to their property as well as practical information to help get them started.
2. the program will help households, who choose to undertake actions suggested by the assessment, with a Green Loan subsidy to significantly reduce the cost of loans of up to $10,000. The loans will be made available through partnering financial institutions. Details on the terms of loans will be available later this year.
Friday, March 20, 2009
Insulation results were good - a thorough and even job with few gaps. This means the insulation can actually work to its quoted R value. Air leakage, however, was at the rate of17.7 air changes per hour at the test pressure of 50 Pa (modern North American and European homes aim for 1.5 - 3.0 at 50 Pa). At normal pressures, this equates to leaving a 35cm square window permanently open, or having the entire volume of air change 3 times per hour. Imagine that in the Canberra winter - whoosh goes your heated air (and money and green house gas emissions) every 20 minutes!
Wednesday, February 11, 2009
Wednesday, February 4, 2009
This is good news but we are concerned that the Australian Government's focus on insulation:
1. will lead to more low quality installation of insulating materials (greatly reducing its cost effectiveness), and
2. ignores the enormous potential offered by simultaneously targeting air leakage control.
- 5% gaps in insulation reduce effectiveness by 50%
- air leakage can account for 30% of a home’s heating and cooling costs
- insulation does not stop air leakage
Friday, January 16, 2009
1. those originating outside the living space
2. those released by things inside the living space
3. those resulting from human metabolism and activities.
Examples of 1: airborne mould spores and pollen, radon in the soil, vehicle exhaust, garden chemicals, outgassing and particulates from insulation
Solution: Separate - make sure your house is well air sealed. Gaseous and particulate pollutants travel into the living space primarily by moving on air currents through holes and gaps in the structure.
Examples of 2: outgassing or particulates released from home furnishings or building materials directly exposed to the interior living space (paints, wall paneling, cabinetry, etc.), evaporation from cleaning and home-maintenance products, mould spores from colonies growing within the house, pollen from house plants
Solution: Eliminate - use less polluting alternatives. Choose low-outgassing paints and finishes, furniture without long-term formaldehyde emissions, less-noxious cleaning products. Find sources of moisture and fix them.
Examples of 3: carbon dioxide, ammonia, methane, water vapor
Solution: Ventilate - that means controlled air change.. NOT relying on air change through permanent gaps and cracks in the building envelope! Local ventilation (exhaust fans) should be used intermittently to reduce humidity levels in kitchens and bathrooms quickly, while general ventilation should be ongoing in order to change the air in the entire house. Controlled ventilation can be passive ie. by opening windows, doors or vents. Mechanical ventilation is required in very air tight houses in cold climates.
Find out more in the article 'Improving Indoor Air Quality - What Works' published by the Healthy House Institute. Or check out the terrific 'Is Your House Killing You?' web site.