The PSU adapters have a wire coming off of it to connect to the motherboard, I don't know if it limits the speed of the fan as I never connected mine to the motherboard, I have my 4 case fans connected to the PSU, all hidden away.
Are you sure that is in Farenheit?? I don't know the exact conversion to Celsius, but that must be only a couple of degrees above freezing. Do you live in Alaska?
There shouldn't be a problem using the chipset fan connector.
Cisco CCNA, Comptia A+, 1/3 through CCNP