The average hvac salary at Lewisville Isd was $59,889 , which is 8 percent higher than the average salary for this job in Texas, and 8 percent higher than the national average for this job . Hvac salaries at Lewisville Isd typically range from $51,979 to $69,326 (25th to 75th percentile). The highest reported hvac salary was $82,618. There are 18 employees at Lewisville Isd with the job title hvac.