What feature distinguishes unit heaters from convectors in enhancing heat transfer?

Unit heaters and convectors are both used to provide heating in spaces, but they operate through different mechanisms, particularly in how they enhance heat transfer. The distinguishing feature of unit heaters is the inclusion of blowers.

Blowers actively move air across a heating element, which promotes more efficient heat transfer compared to the passive heat distribution used in convectors. The operation of a blower in unit heaters increases the velocity of air flowing over the heating element, which helps to circulate heated air throughout the space more quickly and evenly.

In contrast, convectors rely primarily on natural circulation, where warmer air rises and cooler air is drawn in from below without the aid of mechanical fans. While convectors can still be effective in heating a room, they do not achieve the same rapid and controlled air movement that blowers in unit heaters provide.

Therefore, the use of blowers in unit heaters is what primarily distinguishes them from convectors in terms of enhancing heat transfer.