The answer to 'ductwork not cooling' is that there are several common causes, including leaks in the ductwork, blocked or dirty air filters, and issues with the HVAC system itself. Symptoms may include uneven cooling, warm air blowing from the vents, and higher energy bills. The best solution depends on the underlying issue, and in some cases, it's best to call a professional HVAC technician.
If the ductwork has any leaks or gaps, it can cause the cooled air to escape before reaching the rooms. This results in uneven cooling and higher energy usage. Homeowners can often seal minor leaks with duct tape or mastic sealant, but larger issues may require professional duct repair or replacement.