Andy here, reporting this week from sunny Canberra where the ice was thick on my sister’s birdbath this morning. Cate (my sister) has a little brick-veneer-and-tile townhouse near Belconnen which she is gradually retrofitting to make it as energy efficient as possible. So far she has insulated the walls and ceiling, installed a solar power system on the roof, replaced the sliding door out to the patio with a double-glazed one, added insulating cellular blinds to most of the other windows, and installed ‘Magnetite‘ glazing on some of the west-facing windows and the two skylights.
Magnetite is a system that allows you to retrofit a sort of double glazing to existing windows. Basically it adds a perspex cover to the window which is sealed tight and held in place by magnetic strips installed around the edge of the window. The company’s website claims that ‘Magnetite® has been independently tested by WERS (Window Energy Rating Scheme) to demonstrate an improvement in the window thermal performance by over 70%’. I make it a point to never believe a word any company says about their own product, especially when it comes to insulation values. I have found, over the years, that there is more in the way of false advertising and exaggerated performance claims in the energy efficiency field than just about anywhere else. However, in this case, I think a 70% improvement is quite plausible. In Cate’s case the existing windows are single-glazed aluminium sliders which have pretty poor insulation and air-sealing properties. I’m sure the Magnetite provides a much better air seal and the air space between the panes must be helping with the insulation.
The Magnetite system is not cheap. Cate paid $1300 for three small windows and two skylights so she will probably never save enough in energy bills to recoup the cost of the installation. However there are considerations other than payback time that make the investment worthwhile. The big one is thermal comfort which the Magnetite improves considerably. Another one in Cate’s case is sound insulation. She lives on a busy street with neighbours close by and the Magnetite definitely helps to block some of the noise.
Magnetite for Skylights
Where the Magnetite system seems to offer a very good solution is for skylights. Many houses in Australia, like Cate’s, have simple skylights consisting of a bit of clear roofing over a reflective-lined box in the attic with a crinkly perspex sheet sitting in a wooden frame at ceiling height. These can be reasonably effective at allowing natural light into dark spaces but they are awful in terms of energy efficiency and air sealing. I have yet to see one of these ‘skylights’ that had a decent air seal around it. In most cases they simply create a big hole in the ceiling insulation and leak a LOT of air.
As you can see from the photo above, the Magnetite places a clear sheet of perspex under the skylight so it still lets in the natural light. At the same time the magnetic strip that surrounds the Magnetite frame creates an effective and durable air seal will greatly reduce the amount of air leakage through this type of skylight.
Cate has had the Magnetite for about two years now and reckons it was a good investment, especially for the skylights. The other windows in her house a much bigger (which would make installing Magnetite on them expensive and complicated) plus they already have insulating cellular blinds on them so she probably won’t be buying more Magnetite panels but she’s happy with the ones she has.
On a side note, she says that the best thing she has done for the house in summer was to replace the flyscreen doors at the front and back of the house with security screens. These are lockable and have a heavy-duty mesh that would be very difficult to cut or break through. This allows her, in her medium-density urban neighbourhood, to leave the front and back doors open at night in summer and sleep well at night without fear of someone breaking into the house. This means she can get good air-flow through the house at night and cool the Thermal Mass of the floor slab which helps to keep the house cool throughout the hot Canberra summer days.
Drone Mapping for Solar Farms
Ah, bother… I just realised that I forgot to bring the battery charger for my laptop and the battery is about to die. So I will have to complete this story next week. Suffice to say, I had a very eye-opening few days last week working with Anton van Wyk from Spatial Technologies using a drone to perform aerial surveys of four potential sites for solar farms as part of my work with Renewable Energy Wingecarribee Pty Ltd.
It’s amazing what these UAV’s (Unmanned Aerial Vehicles) are capable of. They’re basically little flying robots that are can perform a wide range of functions that would have previously been difficult and expensive if not impossible. There is no doubt that they, and other robot technologies, are going to dramatically change the way we live and work. I worry about where all this will take us in the long run. For now it’s amazing to see what the technology is capable of but it might not be so mesmerising when robots take over most of our jobs.
To be continued…