I took the mini solar oven to work today and unfortunately found a problem right away. The way the building is situated, the mid-morning sun doesn’t start to hit the window I’m using until around 10:30am. As the sun crept into the box I started taking temperature measurements at semi-regular intervals. Here’s what I recorded, it’s a bit disappointing:
10:30 = 75
11:15 = 85
12:30 = 95 – start of full sun in the box
1:30 = 102
2:30 = 98 – moved to the western window which caused the drop in temp
3:15 = 105
4:30 = 109
As you can see, the highest it got was 109 degrees but I was really hoping for around 150. I attribute this mostly to a tint on the windows and a slight haze in the sky. It was a bright sunny day, but I’m guessing there was about a 10% haze.
I’m going to give it another try tomorrow. I’ve added a 15″x15″ reflector panel to the lid to amplify the amount of sun being collected (I’ll take pictures later this week). I know that the reflector will help considerably and the lack of having one on the prototype I built for the backyard last summer was part of the problem with it’s inability to go higher than about 200 degrees.
I’m going to bring home the mini solar oven this weekend and test it outside to see how much of a difference the windows at work make.
Check back tomorrow!