Another thing that people often point to as a negative thing about ketosis is that people can suffer symptoms such as headaches and dizziness in the first few days of a ketogenic diet. Also, athletic performance can suffer until the body adapts to using fat for energy instead of glucose.
Forced air furnace heat exchangers have an average life expectancy of 15 years, with a range typically between 13 and 20 years. Most heat exchangers used in models today today will last between 15 and 25 years and are usually made from aluminized or stainless steel.
The answer to this question depends on a variety of factors and you will need to examine them carefully. Typically, a forced-air gas furnace can be expected to last from 15 to 20 years.Some experts give a range of 13 to 25 years, because there are many variables. For example, some home builders use lower quality units made by well-known manufacturers.ypically a forced-air heat exchanger can be expected to last between 15 and 20 years. Ultimately, heat exchangers fail because of the constant heating and cooling.