Is Irda a chipset chip? (for instance, belongs to Intel ICH?)
a third part vendor device?
is typically a third party device on your average laptop but I think
integrated chipset versions as well.
where can i find a specification for the device?
Which device? Typically from the manufacturers
How can i totally shutdown the Irda device so it consumes 0(zero)
depends on the hardware, there is no generic way apart from not
kernel module for it, which most certainly turns it on.