Air Conditioning & Heater

A heater core is a radiator-like device used in heating the cabin of a vehicle. Hot coolant from the vehicle's engine is passed through a winding tube of the core, a heat exchanger between coolant and cabin air. more...

Home
ATV Parts
Apparel & Merchandise
Automotive Tools
Aviation Parts
Boat Parts
Car & Truck Parts
Car Audio, Video
Manuals & Literature
Motorcycle Parts
Other Vehicle Parts
Personal Watercraft Parts
Racing Parts
Services & Installation
Accessory Installation
Air Conditioning & Heater
Alignment & Steering
Appraisal & Inspection
Battery & Electronics
Body & Paint
Brakes
Cooling System & Radiator
Engine Services
Exhaust & Muffler
Extended Service Contracts
Glass Repair or Replacement
Machining Service
Oil Change & Lube
Other
Performance or Racing Mods
Restoration & Fabrication
State Inspection/Smog
Tire and Wheel Installation
Transmission Service
Tune-Up
Vehicle Shipping
Snowmobile Parts
Vintage Car & Truck Parts
Wholesale Lots

Fins attached to the core tubes serve to increase surface for heat transfer to air that is forced past them, by a fan, thereby heating the passenger compartment.

How it works

The internal combustion engine in most cars and trucks is cooled by a water and antifreeze mixture that is circulated through the engine and radiator by a water pump to enable the radiator to give off engine heat to the atmosphere. Some of that water can be diverted through the heater core to give some engine heat to the cabin.

A heater core is a small radiator, located under the dashboard of the vehicle and consists of conductive aluminum tubing with cooling fins to increase surface area. Hot coolant passing through the heater core, gives off heat before returning to the engine cooling circuit.

The fan for the vehicle's ventilation system forces air through the heater core to transfer heat from the coolant to the cabin air, that is directed into the vehicle through vents at various points.

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 plastic 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.

Air conditioning

In a car equipped with air conditioning, outside air is first forced through the air conditioner's evaporator coil. This can be thought of as a heater core filled with very cold gas, which cools rather than heats the incoming air. In order to obtain the desired temperature incoming air may first be cooled by the air conditioning and then heated again by the heater core.

Engine cooling function

Because the heater core cools the heated coolant from the engine it can act as the radiator of the engine. If the radiator is working improperly, the operator may turn the heat on in the passenger cabin, resulting in cooling the engine coolant and then cooling the engine. This idea only works to a certain degree, as the heater core isn’t large enough nor does it have enough cold air going though it to cool large amounts of coolant significantly.

Read more at Wikipedia.org