We’ve installed a new solar heater. I have been very uncertain about how well it would work, and whether it would be worth the expense, and in fact whether I should buy a ready made one or make one myself. In the end I opted for ready-made, despite the expense, and bought a Solamate.
It’s been running for about six weeks now, and with Melbourne temperatures ranging from about 7-18 degrees Celsius at the moment, we have been surprisingly snug. It’s set up to automatically detect when the air temperature in the panel is warmer than the temperature in the house, and when it is, it runs until either the panel temperature is cooler than the house, or until the house has reached the maximum temperature I selected.
The heater starts up with the tiniest bit of sunshine, and only needs to run for 15 minutes or so to lift the temperature of our lounge room by a degree. It usually starts up around 9.30am each day, and runs off and on depending on the sun and clouds, and most days by the middle of the day it’s 22 degrees, we’ve all got our jumpers off and it feels like summer. The heat is absorbed by the mud brick walls of our house, and slowly released overnight when the heater isn’t running. This means that even though it feels pretty fresh in here, first thing in the morning, it might be 16 or so degrees while outside is only 3 or 4.
I find I don’t mind wearing a hat or coat for a while in the morning till the house warms up, because I don’t get so cold in my bones the way I usually do. When I’m cold all the time I get so desperate for heat that I need to be snugged up to the heater for a long long time before I feel warm in my bones. But this way I get so thoroughly heated in the middle of the day, that I can tough it out for the colder bits.
It’s still autumn though – whether we can get through a Melbourne winter without any supplementary heating remains to be seen, but I’m really hoping we can. The makers of the panel stipulate that you shouldn’t chuck out your conventional heater – you’ll still need it some evenings and mornings. Having the solar heater will simply reduce your bills (significantly) and make your home much more comfortable. For most houses though, which are bigger than ours, the heater might not be quite so effective. Our house is tiny, has great thermal mass, and we have recently upped the insulation and double glazed the windows, to really try and keep the heat in.
If you are interested to try and build one yourself, check out the Solar Sponge. You can also make a panel that doesn’t need a fan if you have a window on a north facing wall with enough space below it for the panel. You put the panel on the wall, open the window a bit, seal the gap, and the warm air flows through the panel into the room.