When shopping for a new gas furnace, there are several things you need to consider. One of the most important factors in determining which furnace is best for your home is the AFUE rating. AFUE is the Annual Fuel Utilization Efficiency, which represents the thermal efficiency of combustion equipment like gas furnaces. Currently, the options for gas furnaces are 80%, 92.1%, and 95%. The next thing that needs to be considered is the heat output needed from the furnace. Smaller homes which need very little heating would need a 45 thousand BTU furnace, while other homes may need 70 thousand, 90 thousand, or 115 thousand BTU. Typically a heat calculation will need to be done for the home to be certain how many BTUs are needed, but occasionally when a furnace just needs to be replaced, the heating capacity can be matched to the old furnace. Another variable that needs to be considered is whether the furnace needs to be up-flow, down-flow, or horizontal. This describes how air actually flows through the furnace. If the air comes into the furnace from the bottom and the duct is attached at the top, then the furnace is up flow because the air flows up from the bottom to the top of the furnace. The desired speed of the air flow is also an important factor to consider. The options are multi-speed and variable speed. Multi-speed means that the furnace has multiple settings for the installer to choose from when installing the furnace, while variable speed means the furnace will adjust its setting as needed during operation. Other considerations for a gas furnace are how many cubic feet per minute of air flow are needed and the cabinet size. Call Ingram's Water and Air today at 1-855-INGRAMS and we can help you find the perfect gas furnace for your home.