Dual fuel systems are a great way to introduce greener home comfort into your existing HVAC systems. These systems will use greener technologies in concert with gas burning systems such as a maximum efficiency gas furnace. The purpose of these systems is to offset the run time of gas burning equipment with a green source such as an air source heat pump. Although, this does not completely remove gas from the equation. Pairing these units together means you now have a capable greener system during heating season. When the heat pump is running the system produces ZERO carbon emissions.