How not to see the Null values for Hours when inpout is 24 hr or 48 hours :     
DECLARE @Hours AS INT
DECLARE @SubtractDate AS DATETIME

SET @Hours=24 /* User input to have hours */
SET @SubtractDate=DATEADD(hh,@Hours,GETDATE()) - GETDATE()

if @Hours>=24 


SELECT CONVERT(VARCHAR(10),DATEDIFF(DAY,'1900-01-01',@SubtractDate))+ ' Day(s) ' +
CONVERT(VARC`enter code here`HAR(10),DATEPART(hh,@SubtractDate))+ ' Hour(s) 'AS [Result]




Else 
SELECT CONVERT(VARCHAR(10),DATEPART(hh,@SubtractDate))+ ' Hour(s) ' AS [Result]
