It is generally not recommended to turn off your air exchanger in the winter. In fact, it is important to keep your air exchanger running during the winter months to ensure that your home has proper ventilation and to prevent excess moisture from building up inside your home. Excess moisture can lead to a variety of issues, including mold growth, structural damage, and respiratory problems. An air exchanger helps to remove excess moisture from the air by bringing in fresh, dry outdoor air and exhausting indoor air. If you are concerned about energy efficiency, there are a few steps you can take to help reduce the energy usage of your air exchanger: Make sure the air exchanger is properly sealed and insulated. Keep the air filter clean and replace it as needed. Set the thermostat to a lower temperature when you are not home or when you are sleeping. Use a programmable thermostat to automatically adjust the temperature when you are not home or when you are sleeping. It is always a good idea to consult with a professional HVAC technician if you have any concerns about the operation of your air exchanger. They will be able to provide specific guidance based on your individual circumstances.