The Sun Lizard - Solar Air Conditioning
by Warren McLaren, Sydney on 09.25.07
Asks an Australian if they’ve been busy or not, and they might reply, “Mate, I’ve been flat out. Like a lizard drink’n.” Colin Gillam, CEO of Alternative Fuels and Energy may well give just such an answer regarding his Sun Lizard solar heating/cooling project. Especially as he has been working on it for the past 16 years. His persistence finally paid off when last month he was scored both the judge’s vote, and the people’s choice vote on the ABC New Inventors TV show.
In basic terms the Sun Lizard harnesses the sun to heat and cool a house. How it does this is a tad more complex. Though not radically so. In summer a photovoltaic panel collects solar juice to power a series of fans that encourage fresh cool air to enter the house from vents at ground level. Come winter you switch modes and now a box on your roof or wall comes into play. A covering sheet of low-iron glass allows for maximum clarity so oodles of sun can enter the box and heat a bunch of steel baffles. These are angled in such a way as to give the collector a capture area more a third greater than its external size. This heated air is then fed back into the house via ducting, again at ground level, to warm rooms. It is continually circulating and reheating (up to 50°C) the air. All without grid power.
A single unit is said to heat and cool an area of 100 sqm (~1,000 sq ft) to up to 10 C° cooler in summer and 4-6 C° warmer in winter. Collin reckons a Sun Lizard can cut heating and cooling costs by 60%, when properly installed on a well designed building.
Municipal libraries are already using the designs. And apparently the United Nations also like the concept. They’ve bought four for use in Afghanistan. ::Sun Lizard, via Red Ferret. (bit of an animal theme going on here!)
Might this just be the solar air conditioning that Lloyd has been lusting after for years? He’s salivated at least once or twice on the topic before.
Wouldn't that just be a solar powered attic fan?
Sounds to me like Doug is right; I had clicked on the link hoping someone had finally commercialized heat driven air conditioning, which is a fantastic idea since higher solar loads provide higher cooling, unlike conventional air conditioning which gets weaker as it gets hotter and more humid. This is much more efficient than connecting PV to air conditioning. The technology is well developed, and is used in hotel minibars where they want to avoid the noise of a compressor, so they use electric resistance heat as the energy input to the cooling system. Sounds wasteful? It is, but when the heat comes from the sun and not electricity, it's a great idea.
Love it! Are there plans for mass production?
Combined with a solar air collector yes.
... plus a solar air heater and ducting to allow for reversable flow and a summer intake under the house.
But Doug's pretty much right -- not much that's new or revolutionary here. I've seen a bunch of these types of systems put together by eco-handy-types. The thing that is new is putting them all together into a consumer product. And it's a pretty nice looking setup.
Note to Lloyd: I've been working on solar cooling for some time (built some of the early prototype solar refrigerators at Energy-Concepts.com). Real solutions are not too far off -- they just need funding.
Since this isn't cooling the air during the summer usage (just pulling in air from ground level) it doesn't help when the outside air temperature is 110 in the shade (as is common here in Phoenix).
Parts of Australia regularly get similar temperatures to Phoenix, if I'm converting to Celcius correctly (110F approx equal to 43C). The website claims to reduce your reliance on fossil fueled air-conditiong, and only to eliminate it in some places, not all. The Sun Lizard isn't a magic bullet, but it's going to be very handy for a lot of people.
We know all about 45+ degree heat in Australia. I'm assuming it's either designed to just reduce your cooling costs in summer, or perhaps drawing cooler air from under the house (which can usually be much cooler even if it is warm elsewhere). I've been to some "Queenslander" homes that are up on stilts, with a wide verandah, and on hot days everyone heads under the house to hang out and cool off, because it's surprisingly cool under there.