The main objective for this week was to devise the main cooling system. After researching models that were similar to what we had in mind, a kit turned up for a Peltier-based cooling unit that utilized an 80mm water cooling block along with two TEC1-12706s, two heat sinks, and two 40mm DC fans. For our system, we wanted to use something similar, but with three TEC1-12706s, so a 120mm water cooling block was found online. Wanting to increase airflow in the cab, I found a cheap DC blower centrifugal fan that may suit our application well.
With these changes in mind, I set about creating a CAD sketch to better visualise the design, and to get an idea of the device size and how it might be enclosed. Luckily, my limited experience with FreeCAD was handily supported by the vast library of user-created CAD renderings supplied by grabcad.com. The resulting sketch for the Peltier cooling unit is attached to this post. Three 40mm TEC1-12706s are sandwiched between a 120mm x 40mm water cooling block and three heat sinks. The cold side of each Peltier module faces a heat sink with some thermal paste between. The heat sinks help make the air colder around the cold side. On the other side, the Peltier modules' hot sides are mounted to a 120mm water cooling block. The heat from the modules is transferred to the water in the cooling block, which is then piped out to a radiator/fan assembly to be cooled. Since this assembly will be mounted in the car's window, the heat in the water gets removed from the car. Because the Peltier modules try to keep the temperature differential between the hot and cold sides the same, cooling the hot side will make the cold side even colder.
Comments