The answer to 'air filter high energy bills' is that a dirty or clogged air filter can significantly increase your HVAC system's energy usage and costs. A dirty filter forces the system to work harder to circulate air, leading to higher energy bills. Symptoms include reduced airflow, uneven heating/cooling, and the system running more frequently.
The solution is to replace your air filter regularly, typically every 1-3 months depending on usage and environmental factors. This is a simple DIY task that can save you money on your energy bills. However, if you continue to have high energy costs even after changing the filter, it's best to call a professional HVAC technician to inspect your entire system for other potential issues.