Green Loans - Home Sustainability Assessments

Energy Imaging have just become Green Loans Home Sustainability Assessors.

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.

Green MLA puts home to the test

ACT Greens MLA, Caroline Le Couteur, bravely invited Energy Imaging and The Canberra Times into her home to assess the quality of her insulation and measure the rate (and locate the areas) of air leakage. A story was published in the Canberra Times Earth Hour Supplement on March 18.

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!

The Helix magazine does the draft test

The February-March issue of the CSIRO's The Helix magazine (www.csiro.au/thehelix) features a story about draft proofing and Energy Imaging, on page 8.

Free insulation for millions of homes!

Today, Kevin Rudd announced that the Australian Government will install free ceiling insulation in around 2.7 million Australian homes (http://www.pm.gov.au/media/Release/2009/media_release_0783.cfm)

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

Overseas research has proven that air leakage control is the cheapest way to reduce energy loss from homes and—in combination with properly installed insulation—is the highest priority item for reducing energy use in buildings. Energy Imaging's results reveal that Canberra homes lose much of their winter heating and summer cooling via air leakage and improperly installed insulation.

Indoor air quality... easy as 1, 2, 3

Pollutants can be organised into three categories:
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.

The low down on downlights

"Down, down, down with halogen down lights!" is my new mantra. "Don't do it!" I yell passionately in my energy auditing nightmares.

Quite simpy, halogen downlights are a disaster when it comes to energy efficiency, for the following reasons:
1. they are energy guzzlers
2. they create gaps in your insulation, reducing thermal efficiency dramatically
3. they get hot and so make their own little convection current which sucks the warm air, that rises to the ceiling, up into the roof space... making the pressure difference (or stack effect) in the room greater and drawing more cold air in from the cracks and gaps near your floor. Goodbye heated air, goodbye comfort and ooroo money!

When we run an air leakage assessment, standing beneath a downlight is like standing beneath a small ceiling fan, as air rushes in from the roof space. The thermal image above is of a downlight (not switched on) while we are depressurising the house - the rays of yellow are caused by the warm air from the roof space being drawn in around the edges of the unsealed and uninsulated, hot, energy guzzling downlight! Imagine the opposite happening in winter as you spend your precious pennies trying to keep your house warm... because that is exactly what happens :-(

A couple of other good reasons to avoid downlights:
a. they make gaps in the ceiling through which insulation fibres, dust, dirt and pollutants can drift into the house
b. they are a fire hazard

Read a more thorough analysis by Four Corners' reporter Jonathan Holmes and check out the options for making the best of a bad bunch if you're stuck in a house with lots of standard halogen downlights. There are several places online where you can check out more energy efficient downlight options and downlight covers that reduce the gaps in your insulation and the risk of fire.

Passive solar & sustainable... but how leaky?

Ric Butt, of Strine Environments, designs unique, passive solar sustainable houses that are typically warm, bright and spacious, with full glazing to the north. The thermal design of Strine homes virtually eliminates the need for heating and cooling throughout the year, even in the Canberra region. They are made from heavily insulated, precast concrete panels with a high quality finish. The panels are made to exacting standards (by Strine Products in Queanbeyan, NSW) to ensure that they fit together perfectly on site, and incorporate all necessary conduits for cables and services.

Yesterday, we put one of Strine's homes to the test with our blower door and thermal camera... and the results were impressive.

Our testing of Canberra homes (new and old) has so far shown the average number of air changes per hour (ACH) at 50 Pascals to be around 20. Modern European homes, built using advanced sealing techniques, aim for 1.5 - 3.0 ACH at 50 Pa (ie. they are very air tight, energy efficient and comfortable) and require mechanical ventilation systems to maintain healthy indoor air quality.

The three bedroom Strine 'Milennium' home, completed in 2006, had just 6.2 ACH at 50 Pa. At normal pressures of ~ 1 - 4 Pa the house was having roughly 1 - 1.5 ACH. For healthy indoor air quality 0.5 - 1.0 ACH are recommended. So the house is very air tight by Australian standards and if efforts were made to tighten it even further the homeowners would need to consider installing a heat exchange, mechanical ventilation system (to ensure good air quality when all the windows, doors and solar chimneys were closed).

The temperature of the precast concrete walls was remarkably even. Comparison of the external and internal temperatures of a section of eastern wall at 11.30 am on a sunny, 25 degree day showed a 20 degree difference (40.8 & 20.6 degrees, respectively).

Strine Environments is a unique partnership between Strine Design, Strine Products and Strine Building and can provide a leading edge, seamless environmental design and construction process.