When I press the defrost button in my car, it turns both the heat and AC on at the same time. I assume this is to remove water from the air with the AC, then warm up the air increasing its capacity to hold water with the heat.
Your assumption is correct
Also your car automatically calculates the condensation point and keeps the temperature and air moisture low enough not to cause any fogging on your windshield.
Source: I’ve been programming AC unit controls for cars for the last 10 years
in a lot of newer cars they can actually use the A/C to heat and cool the car, rather than using excess engine heat or an electric heater which is especially helpful when it’s cold and you’ve only just started the engine!
Fun fact (well, I suspect you know this already, but some didn’t, I had discussion with someone arguing with me that this is not true):
AC and a heat pump are basically the same thing, AC is just pumping the heat outside instead of inside.
Also when you say modern cars I am assuming you might be talking about EVs. Using a heat pump requires less energy than using resistive heating so it could be energy saving measure.
ICE cars on the other hand can get the heat from engine “for free” (not really, but since the heat will be produced anyway whether you use it or not, so why not use it?) so a heat pump might make a bit less sense in them.
When I press the defrost button in my car, it turns both the heat and AC on at the same time. I assume this is to remove water from the air with the AC, then warm up the air increasing its capacity to hold water with the heat.
Your assumption is correct Also your car automatically calculates the condensation point and keeps the temperature and air moisture low enough not to cause any fogging on your windshield. Source: I’ve been programming AC unit controls for cars for the last 10 years
in a lot of newer cars they can actually use the A/C to heat and cool the car, rather than using excess engine heat or an electric heater which is especially helpful when it’s cold and you’ve only just started the engine!
Fun fact (well, I suspect you know this already, but some didn’t, I had discussion with someone arguing with me that this is not true):
AC and a heat pump are basically the same thing, AC is just pumping the heat outside instead of inside.
Also when you say modern cars I am assuming you might be talking about EVs. Using a heat pump requires less energy than using resistive heating so it could be energy saving measure.
ICE cars on the other hand can get the heat from engine “for free” (not really, but since the heat will be produced anyway whether you use it or not, so why not use it?) so a heat pump might make a bit less sense in them.
Air-conditioners are in a way dehumidifiers, so that makes sense