Cheap Foam Cooler to Cool Greenhouse

I used a cheap Amazon plastic greenhouse this winter and successfully kept several plants alive. I learned a lot in the process and one important thing that I learned was that you have to regulate the temperature. This isn’t a true swamp cooler but it served to bring fresh cool air in from outside cool down some thermal mass and circulate hot air from the peak of the greenhouse. I am in zone 5b where we had clear sunny days in the winter with temperatures hovering near freezing but because of the sunshine it was getting too warm in the greenhouse for the plants that I had in there. I also wanted to create air circulation and this inexpensive computer fan and foam cooler combination achieved both.