If your home has an Air-Exchanger included in the systems, this component needs maintenance just like the furnace. Many home buyers (and owners) don't know what these components do, or how they operate.
Because newer homes area sealed tighter, they need to have fresh air integrated on a regular basis. These components are meant to do just that by removing stale (contaminated) air, and introduce fresh air so that the home can essentially "breathe". Exchangers transfer some of the heat (or heat and humidity) from the outgoing interior air to the incoming exterior air in order to help your home stay cooler or warmer as efficiently as possible.
There are different types of air exchangers: HRV (Heat-Recovery Ventilator) and ERV (Energy-Recovery Ventilator). Models and manufacturers vary, so the best advice for anyone is to "make sure they read the manual and follow the maintenance recommendations"... if a manual isn't in the home, it will be available on the manufacturer's website.
These systems are not dehumidifiers, and do not take the place of bath fans, although they are being used as such in some homes. Yes, during the heat and energy transfer from indoor to outdoor air, there can be some condensation/humidity that is eliminated or exchanged during certain times of the year, but DO NOT rely on these to eliminate excessive moisture in the home.
I have been in many homes where these systems are turned off or unplugged because people don't understand them. Be informed, read the manuals, know when you should run them (or not) and do the maintenance....
ASHI Certified, Pinnacle Inspections strives to give our clients the best reporting and advice. They regularly ask "how" to get things done, and hopefully we can share some useful tips or products on this blog.