I live along the northern border of our country, quite close to Canada. Here, the Winter season weather is nasty and severe. Because of this, I have invested in a dual fuel system to handle my home’s year round temperatures. Between the horrendous Winter seasons & humid summer seasons, I am forced to run a heating or cooling unit just about all year round. The cost of temperature control can be excessive. A dual fuel system partners a natural gas furnace with an electric heat pump, & helps to trim costs. The electric heat pump offers both heating & cooling capacity, actually working as an a/c during the summer season months. During the cooler weather, the heat pump reverses operation, finding heat in the outside air & pumping it inside. Because the heat pump simply moves heat from one location to another, rather than burning fossil fuel to create heat, it requires very little energy. It is also quiet, clean & quite safe. There is no danger of fire, fumes or carbon monoxide poisoning. It costs a lot less to operate the heat pump than the gas furnace. Unfortunately, the heat pump is only effective until the outside temperature drops below cold. At that point, it can’t keep up with demand any longer. The dual fuel system automatically switches to the gas furnace. The furnace keeps the apartment perfectly moderate & comfortable, until the outside temperature rises back above the freezing point. By splitting the workload between the heat pump & furnace, I take advantage of the most beneficial fuel source & noticeably save currency.