If he has a ceiling fan and A/C that use RF, the FCC ID numbers should be on the original remotes for the ceiling fan and A/C. The remote contains the RF transmitter and it is the transmitter that requires FCC certification tests before it can be marketed in the US.

There are several ceiling fans that are RF operated. I list several FCC ID numbers on my web pages. I have two fan remotes on my work bench right now that users sent me so I could capture the RF codes. All the fan remotes I have seen have the FCC ID number molded into the plastic case back.

I have yet to encounter an RF controlled A/C but there may be some.