Is central air always heat and cool?

Answer 1

No.
Think of it like this......Maybe your current heating source is a boiler, either steam or hot water. This will provide heat via pipes and radiators. If you want to air condition your house, a contractor will have to install a seperate system which consists of the condenser (outside unit) and evaperator. (indoor unit). The indoor unit can be either ducted, in which case the evaperator will be part of an air handler which will blow the air through ductwork you need installed, or else ductless such as the case with a Mitsubishi mr. slim unit.
The contractor may install a seperate T-stat to control cooling only or he may upgrade your t-stat to control both heat and cool from the same t-stat.

If you have forced hot air for your heating system, you need to add an evaperator in the plenum (above or below the furnace)(depends upon upflow or downflow applications) and have a condenser and controls installed.
Same options as T-stat listed above.

If you are speaking in terms of a commercial industrial set-up, then you have options such as a 2 pipe or 4 pipe system. A 2 pipe system can only perform heating or cooling and requires a manual changeover, the 4 pipe system is capable of running both at the same time.

I hope this helps!
Newt

Answer 2

Typically the term is used for AIR conditioning. instead of several window air units there is just one "central unit that distributes it to the rest of the home via ducts. Years ago furnaces were called "gravity heaters" they used the "hot air rises principal and did not have a fan to circulate the air. Boilers and hot water heat do not use fans to distribute the heat. Air CONDITIONING is not just a process by which the air is cooled the humidity is also removed from the air, so the air has been conditioned. In dry areas they actually put humidity into the air to cool. "swamp coolers"

Answer 3

generally the term is used for air con. as a replace of various window air gadgets there is purely one "considered necessary unit that distributes it to something of the abode with the help of ducts. Years in the past furnaces have been referred to as "gravity warmers" they used the "warm air rises vital and did no longer have a fan to pass the air. Boilers and warm water warmth do no longer use followers to distribute the warmth. air con isn't in basic terms a technique via which the air is cooled the humidity is likewise faraway from the air, so the air has been conditioned. In dry factors they actually positioned humidity into the air to relax. "swamp coolers"

Answer 4

NO it used to be just heat!

Answer 5

No, depending on the design it can be either, or both.