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.
1 Propane furnaces last longer than electric heat pumps: Propane-fueled furnaces last 5 to 10 years longer than electric heat pumps, on average. 2  Propane is more dependable than electric: Propane can be stored safely in a tank on your property, while electricity is subject to power outages. An electric heat pump produces heat below body temperature (98.6Â°F), so the air actually feels cool when placing your hand in front of a vent. 2  Propane furnaces last longer than electric heat pumps: Propane-fueled furnaces last 5 to 10 years longer than electric heat pumps, on average.