It is safe to say that everything that is tangible has an expiration date. Even our bodies will expire at some point. And like our bodies most tangible items will last longer the better we take care of them. We visit our doctors regularly so that we can identify any unforeseen issues that could be lurking in our bodies. And we also visit our doctors to make sure that all our organs are healthy and functioning in the most optimal way. If an issue is discovered, we immediately take the necessary steps to rectify the problem in the best way possible. If we give the same attention to other tangible items around us, the lifespan can be extended. For example, the HVAC unit is perhaps one of the most used machines in our homes. So, it makes sense to maintain the unit so that it could perform in the most efficient way. Most HVAC units have an average lifespan between 15 and 20 years, but in some cases, an HVAC unit could last up to 25 years. Of course, it all depends on the amount of maintenance the unit receives as well as how often the unit was used. While the unit might lose efficiency, it is possible to extend the life of an HVAC unit with regular maintenance. However, it is recommended that once an HVAC system is near or at its expiration date that it is replaced for a more efficient unit. It would be nice if we could replace our bodies for a more efficient one when we expire as well.