Tell us about yourself!
Welcome to Arduino
3D Printing Class
Tell me if i wrong, that Heatpipe optimal function was desinged with the base down and the disipator up, because the gas in heat pipe were liquid in the base and gaseous in the upside. If you put inverted, the cooled heatpipe probabliy did not was eficiently. Maybe you better performance with an solid Alu disipator and a coolerfan.Sorry for my bad english
I think you need increse the heat disipation for better termal jump. If you can down the temp of the hot side of peltier cell in 5° or 10°, your cooled side probably down in 5° lower temp.