def fanlist(refreshdata = false)
      refresh if refreshdata
      list.each_with_object({}) { |(name, sensor), flist| flist[name] = sensor if name =~ /.*fan.*/ }
    end
def fanlist(refreshdata = false)
      refresh if refreshdata
      list.each_with_object({}) { |(name, sensor), flist| flist[name] = sensor if name =~ /.*fan.*/ }
    end
returns a hash of fan sensors where the key is fan name and value is the sensor