We don't have one, but talk about getting one each fall, as we have an open underbelly, and the floors can get mighty cold.
Here is what I used as my search words "Radiant Floor Heating for Under Area Rugs" most other combos, only pulled up heated pet mats.
https://www.amazon.com/Speedheat-Rug.../dp/B018XXPCHQ
This one says it uses 1.4 amps of power. Very simular to my heated mattress pad.