I don't know but my outside unit has been making a relatively loud continuous buzz when it is running. This has been the case for at least a couple months (that I have noticed) but the unit seems to otherwise be functioning fine (house still cools down well enough). My concern is that it could be an indication of a problem that should be tended to before a breakdown or other damage occurs.
needs oil..
cicadas
Have you checked the breaker outside by the unit
If you are talking about elements, they are electrons.
The outdoor portion of the central ac unit is what gives up the heat from indoors, so it has to be outside. For a more thorough explanation see the question: How does air conditioning work.
No, but it's a good idea to protect any metal equipment from extreme weather.
keep it closed the windows .but if need fresh air from outside , open the windows.
What about them?
yes you can
To set up a continuous drain system for a portable air conditioner, you can connect a hose to the unit's drain outlet and direct it to a nearby drain or outside through a window. Make sure the hose is securely attached and sloped downward to allow proper drainage. Check the hose regularly to ensure it is not clogged or blocked.
Central air conditioning systems are designed to provide ventilation by bringing in outside air. Leaving a window open would tend to defeat the cooling effect.
No, an air conditioner does not bring in outside air. It cools and circulates the air already inside a building.