I have a 2009 Prius with an Enginer 4kwh PHEV conversion. The DC to DC converter and battery compartment get very hot. I am seeking advice on how to tap in to the Air Conditioner ducts to cool the spare tire compartment. Has anyone tried this?
In the 12v battery well there is a vent to outside air, it should be easy to fit an electric fan similar to the one that cools the HV battery with some flexible plastic ducting from B&Q to force vent that area. Most cars have a fan in the heater system so you should be able to source one from a breakers yard.
That should help but the fans fitted to the dc to dc converter are probably computer style fans and do not move much air. The turbine type of fan of the type used for the HV battery moves a lot more air and could easily be controlled by a thermostat if required. I have not investigated if there is a vent in a similar position on the other side of the car, if so the turbine fan could be put in place of the small bin under the (for the US) drivers side rear light making a cross flow inlet outlet set up that would also cool the batteries.
The only down side with a thermionic converter using the Peltier effect is the moisture factor having condensation forming on the cold side of the converter. It's like frost in a freezer. If not dealt with, it could cause corrosion damage. I've seen thermionic converters used in "overclocking" applications with CPU's in computers. Condensation was a problem that resulted in corrosion. I would much rather conside an active ventilation sysyem using a couple of dash or roof mounted solar panels and an active fan and duct system to move air through the trunk compartment. I would make this system separate with the electrical system in the vehicle.
Checked trunk vents today and there are vents on both sides making a forced vent cross flow system fairly easy.
