DIY Solar Powered Window Air Conditioner: Part 4, Upgrade to 48v/Smoke Test

Fans/Pumps/Arduino on 12v circuit, Peltiers on 48v Circuit

Let’s make some upgrades to the Solar Peltier System. Since starting this project, I’ve learned a lot about planning power budgets, how power supplies generate heat, how amperage at lower voltages can turn into a lot of heat, and how heat moves in an air conditioner. I’ve pulled the unit out of the window and started some upgrades that definitely keep things cooler. Keeping the power supply and lines cooler means more energy is available to power the Peltier modules and actively cool the room. I’m starting to understand why so many of the Peltier projects I see online fail — they’re probably introducing more heat to the room than they save. The all 12v system generates an unsafe amount of heat in the wiring, so let’s get that voltage up and decrease the amperage going through the wires!

48v @ 6A is much nicer than 12v @ 24A! At 12v, the wires were easily 140F (60C) or more, and I’m not interested in living to the ripe old age of “died in a house fire.”

Upgrades

So here’s a pretty simple laundry list of my current upgrades:

1. 48v 400W power supply, this should also stay cooler, since it will be running at lower power than it’s full rating. The previous supply was right up (and even above) it’s actual rating, which probably was causing some…