Many retailers, including AllParts Heating, RepairClinic and HVAC Parts Outlet, stock Tempstar furnace parts. RepairClinic and HVAC Parts Outlet are online stores, while AllParts Heating also has a brick-and-mortar store in Milwaukee, Wisconsin. AllParts Heating offers lower Internet-only prices at its online store.
Current Tempstar furnaces satisfy or exceed the efficiency standards published by the U.S. Department of Energy, but to achieve a heating system’s potential efficiency, all parts of the system must match. Annual fuel utilization efficiency is the metric used to evaluate gas furnaces; it determines the proportion of the fuel in a given year that is used for heating and not wasted. The minimum AFUE per Energy Star requirements is 90 percent, while the minimum required by the DOE is 78 percent. No furnace can reach 100 percent efficiency, as some part of the fuel’s heating potential is inevitably lost. Legislation requiring furnaces to achieve minimum energy efficiency was introduced in 1992, before which gas furnaces with efficiency ratings between 60 and 78 percent predominated on the market.
DOE standards are designed to enable consumers to compare expected annual costs across multiple systems. Consumers living in particularly cold areas typically save more with a furnace with higher AFUE. The variables affecting the level of savings include exact utility costs, weather patterns and the overall energy efficiency of the house.