Adding Unit with Value along with timechart

Dear Experts, We are trying to add unit with value with timechart. My query is : index = xyz sourcetype = csv source = "C:\\Users\\co*" | eval Capacity =IPDU1_power+IPDU2_power | timechart avg(Capacity) by Rackno This query will given output like Capacity by Rack in timechart, I want to add "KW" unit with Capacity of each rack. Please help I try with option | eval Capacity=Capacity."KW" this did not work