AC Works Fine - but "Auto Climate" sets fan speed too low
Discussion
Hi Folks, peculiar issue I'm trying to get some advice on:
I have a '13 DB9. The AC works fine, very cold and low/hi system pressures are right-on. I can freeze myself out of the car if I set it to "Low" and fan speed "High" manually.
HOWEVER, when I turn on the "Auto" mode, it feels like it's setting the fan speed far too low to achieve the set temperature. For example, If I have the temperature at 19 degrees when it's 32 outside, it might put the fan on "3" for a minute, but will then drop to a low setting pretty quickly...long before it's a comfortable 19 in the car. The air coming out is still ice cold, that's all fine, but it just seems like it thinks it's achieved the set temperature when it hasn't.
I can manually adjust it higher, and be comfortable. But I'm curious if there's some sensor that might be getting a bad read, and needs to be replaced...Cabin temp perhaps? Any suggestions?
I have a '13 DB9. The AC works fine, very cold and low/hi system pressures are right-on. I can freeze myself out of the car if I set it to "Low" and fan speed "High" manually.
HOWEVER, when I turn on the "Auto" mode, it feels like it's setting the fan speed far too low to achieve the set temperature. For example, If I have the temperature at 19 degrees when it's 32 outside, it might put the fan on "3" for a minute, but will then drop to a low setting pretty quickly...long before it's a comfortable 19 in the car. The air coming out is still ice cold, that's all fine, but it just seems like it thinks it's achieved the set temperature when it hasn't.
I can manually adjust it higher, and be comfortable. But I'm curious if there's some sensor that might be getting a bad read, and needs to be replaced...Cabin temp perhaps? Any suggestions?
andratch said:
Hi Folks, peculiar issue I'm trying to get some advice on:
I have a '13 DB9. The AC works fine, very cold and low/hi system pressures are right-on. I can freeze myself out of the car if I set it to "Low" and fan speed "High" manually.
HOWEVER, when I turn on the "Auto" mode, it feels like it's setting the fan speed far too low to achieve the set temperature. For example, If I have the temperature at 19 degrees when it's 32 outside, it might put the fan on "3" for a minute, but will then drop to a low setting pretty quickly...long before it's a comfortable 19 in the car. The air coming out is still ice cold, that's all fine, but it just seems like it thinks it's achieved the set temperature when it hasn't.
I can manually adjust it higher, and be comfortable. But I'm curious if there's some sensor that might be getting a bad read, and needs to be replaced...Cabin temp perhaps? Any suggestions?
I don't have a suggestion, but a comment. I have a '13 DB9. The AC works fine, very cold and low/hi system pressures are right-on. I can freeze myself out of the car if I set it to "Low" and fan speed "High" manually.
HOWEVER, when I turn on the "Auto" mode, it feels like it's setting the fan speed far too low to achieve the set temperature. For example, If I have the temperature at 19 degrees when it's 32 outside, it might put the fan on "3" for a minute, but will then drop to a low setting pretty quickly...long before it's a comfortable 19 in the car. The air coming out is still ice cold, that's all fine, but it just seems like it thinks it's achieved the set temperature when it hasn't.
I can manually adjust it higher, and be comfortable. But I'm curious if there's some sensor that might be getting a bad read, and needs to be replaced...Cabin temp perhaps? Any suggestions?
I have a 2015 V8V, so similar aircon, but maybe a different map in the processor to compensate for the bigger DB9 cabin. If my car had been sitting in 32 deg, so that it's hot inside, if I get in and start it the first thing my system does is to switch to "Recirc" and crank the fan speed up to high to bring down the temperature as quickly as possible. If I have a criticism, mine will stay in "Recirc" with the fan running on high for too long, so I'll usually touch the button to turn "Recirc" off to get it back.to normal. I just run my system on 18 or 19 target and fully auto and it works fine, but being in the UK we maybe don't see high temperatures as often as you.
Are you running the system on full auto, or do you have any of the vent directions selected? And does yours automatically go into "Recirc" if it's hot in the car?
The answer I suspect is the Proportional, integral and derivative controller set up.
It's like my partner, she is always playing around with the temperature knobs and never leaves it long enough to settle (too impatient ). Hence its blowing hot one minute and cold the next.
A Proportional-Integral-Derivative (PID) controller is a feedback mechanism used in automation to maintain a process variable (like temperature or speed) at a desired setpoint by calculating an output based on the current, accumulated, and predicted error, combining proportional (P), integral (I), and derivative (d).
Your best course of action if you are getting into a hot car is to set it manually to cool the car down to your desired temperature and then switch the system to Auto to keep it there and vice versa for a cold car.
It's like my partner, she is always playing around with the temperature knobs and never leaves it long enough to settle (too impatient ). Hence its blowing hot one minute and cold the next.
A Proportional-Integral-Derivative (PID) controller is a feedback mechanism used in automation to maintain a process variable (like temperature or speed) at a desired setpoint by calculating an output based on the current, accumulated, and predicted error, combining proportional (P), integral (I), and derivative (d).
Your best course of action if you are getting into a hot car is to set it manually to cool the car down to your desired temperature and then switch the system to Auto to keep it there and vice versa for a cold car.
Edited by F1NDW on Sunday 14th December 22:55
Gassing Station | Aston Martin | Top of Page | What's New | My Stuff