Greenhouse: Greenhouse container experiment, 1 by stressbaby

stressbaby wrote:
Here are the final results of my container experiment. It was originally designed to see whether black painted containers were better or worse than containers with black ink. It was expanded to include different types of paint, different painting techniques, and a container in a black plastic bag. I took a total of 4 sets of measurements, but I excluded a couple when I realized that the container was inadvertently shadowed. To further minimize any biases based on the positions of the containers, I rotated the containers through different positions on the south end of the greenhouse. I measured the morning temperature, then measured again in the evening. By subtracting the two, we have the heat gained and stored in the container, and this is the heat released at night. I calculated this difference (DIF) for each day, then I averaged the DIF. The chart below shows the average increase in temp for each of the different containers. The higher the number on the chart, the more effective that container treatment was.

This is the key:
#1 ACE Black enamel, 1/2 gal, painted completely
#2 ACE Black enamel, 1 gal painted completely
#3 Kryon Black, 1/2 gal, painted completely
#4 Kryon Black, 1/2 gal, 3 sides painted
#5 Kryon Black, 1/2 gal, 1 side painted
#6 Kryon Black, 1 gal completely painted
#7 1/2 gal clear, blue food coloring
#8 1/2 gal clear, black ink
#9 1/2 gal clear
#10 1/2 gal clear in black plastic bag

I draw these conclusions:
ACE black enamel worked better than the Kryon. Therefore, there are clearly differences between paints.
The container in the black plastic bag was inferior to both paints.
Blue food coloring is inferior to black ink or any paint.
Covering a container with a black plastic bag is better than nothing, but inferior to most black paint treatments.
Black ink was inferior to all of the painted containers except for the one painted only on one side.