|With brackets prefixed, these are ready to lift|
|One up, and one more to go!|
Getting them up there is a bit dodgy as I have to use a ladder and tried to drill and fix them from the side, but this will not work, and is too unsafe. I am riveting them on, but you still need to get a firm grip on the riveter with both hands at the moment of truth - dangerous!
I tried the ladder at the centre of each of the sunboxes, the safest location for working, and boy am I glad I built them strongly, of 6mm skin and stout 25x25x3mm aluminium angle across the top front face. I customised a little wooden worktable to fit in the top of the boxes so the panels don't have to take my weight, or be bouncy once I am up there. It is quite firm once the table is in position. Because the face of the sunboxes is glassy, there is nothing to stop the ladder falling sideways, so the first thing to do up there is to fasten a line to the wall brackets, and fasten myself to the same brackets.
Once up there, it was a case of locally drilling a hole in the roofs for the eight brackets, and then using the longest available rivets to fasten the mirrors down. Peel off the blue plastic sheet, and then get down to safety!
Now for the important bit! Before doing this, and earlier in the day, the temperature in the boxes was about 24-25ºC. The temperature sensor is in the east panel, the one I have done first. the sensor is shrouded in reflective foil to ensure it measures air temperature, not just solar irradiation.
Within 5 mins of re-sealing the panels and washing the top glass, the air temperature inside zoomed up to 33.5º. The temperature of liquid coming down from the panels went up. A five to eight degree jump is what I had been hoping for.
|It really is high up there!|
The benefit of these should only be when the sun is shining, strong or weakly. On completely overcast days, there will be no downward reflection. But I keep a weather record, as does my roof, so there is an indication of correlation between sunniness and improved harvest.