Ask any driver here in Nigeria what the most important feature is on their car and many would probably answer, “My air conditioning!”
It might be hard to argue that point.
A lot goes into delivering ice cold air when you push that A/C button, or hot air for that matter. That’s when the HVAC system in your car kicks in.
HVAC stands for Heating Ventilation and Air Conditioning
Most HVAC concerns occur when you least expect it, and often at the most inconvenient times. No heat to defrost the windshield? Roasting in the summer heat?
The vehicle’s heating, ventilation and air conditioning system is composed of three sub-systems that all work together to provide conditioned air to the vehicle cabin.
The heating part takes heat from the engine coolant and transfers it to the incoming air. The ventilation part moves and directs the air within the cabin. And the air condition part cools and dehumidifies the air within the cabin. When they’re working normally they keep you comfortable during all weather conditions.
Key components of the heating, ventilation and air conditioning system include:
– Heater Core
The 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. 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.
Any liquid-cooled car engine has a small device called the thermostat that sits between the engine and the radiator. … Its job is to block the flow of coolant to the radiator until the engine has warmed up. When the engine is cold, no coolant flows through the engine.
– Blower Fan
The heater blower motor forces air through the vents. You are able to control the speed of the motor through switches, buttons, and dials on the dashboard. The motor contains a resistor which allows it to change the speed of the fan.
– HVAC Controls
HVAC (Heating, Ventilation and Air Conditioning) equipment needs a control system to regulate the operation of a heating and/or air conditioning system. Usually a sensing device is used to compare the actual state (e.g. temperature) with a target state.
The condenser is basically a radiator, and it serves the same purpose as the one in your car: to radiate heat out of the system. The refrigerant enters the condenser as a pressurized gas from the compressor. The process of pressurizing the gas and moving it to the condenser creates heat, but air flowing around the twisting tubes of the condenser cool the refrigerant down until it forms a liquid again.
– Compressor and Evaporator
Compressor: The compressor is a pump driven by a belt attached to the engine’s crankshaft. When the refrigerant is drawn into the compressor, it is in a low-pressure gaseous form. Once the gas is inside the pump, the compressor lives up to its name. The belt drives the pump, which puts the gas under pressure and forces it out to the condenser. Compressors cannot compress liquids, only gasses.
Evaporator: his is where the magic happens. While all the other parts of the system are located in the engine compartment, this one is in the cabin, usually above the footwell on the passenger side. It also looks like a radiator, with its coil of tubes and fins, but its job is to absorb heat rather than dissipate it.
Leaks, worn or malfunctioning components can cause a loss of heat, poor or no air flow, insufficient cool air, noises or objectionable odors.
Coolant leaks can also cause engine overheating which can severely damage the vehicle’s engine.