The duty of a heating system is to heat the places where people live especially in winter seasons. The more clear definition is to heat the ambient so temperature of human body is adjusted in comfort conditions frame. As a result of this adjustment, there is a balance between the amount of heat which is produced in the human body and given to the ambient by human body. Thus, people feel comfortable physiologically.
The expected features of a heating system can be characterized as below:
1- The temperature of the ambient must be 20 oC - 22 oC and this value must be stable.
2- The heating system must be adjustable.
3- Ambient air (indoor) must not be brought to a worse situation with the heating system.
4- Disturbed external currents must not be creating during the heating operation.
5- Purchasing and operating costs must not be higher for the heating system.
6- Heating system must be environmentally clean.