Control
Once the engine has warmed up, the coolant is kept at a more or less constant temperature by the thermostat. The temperature of the air entering the vehicle's interior can be controlled by using a valve limiting the amount of coolant that goes through the heater core. Another method is blocking off the heater core with a door, directing part (or all) of the incoming air around the heater core completely, so it does not get heated. Some cars use a combination of this system.
Simpler systems allow the driver to control the valve or door directly (usually by means of a rotary knob, or a lever). More complicated systems use electronics to control the valve or doors.
Cars with dual climate function (allowing driver and passenger to each set a different temperature) may use a heater core split in two, where different amounts of coolant flow through the heater core on either side to obtain the desired heating.
Read more about this topic: Heater Core
Famous quotes containing the word control:
“Teenage boys, goaded by their surging hormones ... run in packs like the primal horde. They have only a brief season of exhilarating liberty between control by their mothers and control by their wives.”
—Camille Paglia (b. 1947)
“Not being able to control events, I control myself; and I adapt myself to them, if they do not adapt themselves to me.”
—Michel de Montaigne (1533–1592)
“The three-year-old who lies about taking a cookie isn’t really a “liar” after all. He simply can’t control his impulses. He then convinces himself of a new truth and, eager for your approval, reports the version that he knows will make you happy.”
—Cathy Rindner Tempelsman (20th century)