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.
Air conditioners and heat pumps last an average of 10 to 12 years, while furnaces have a life span of around 15 to 20 years. If your equipment is within those ranges, expect more repairs in the near future. Technology changes all the time. This is as true for your heating and cooling system as it is for your phone.