Automatic climate control?
August 28, 2007 7:25 AM Subscribe
First car with automatic climate control. How does it work?
About a month ago, I bought a 2008 Subaru Forester. It's the first car I've owned that includes automatic climate control, and the owner's manual isn't particularly clear on how it works. I've been running it in "semi-automatic" mode, giving me greater control over settings, and since it's been hot lately and most of my driving is done during the day, I've almost always kept the temperature at its lowest setting (65F). However, now that's it's starting to cool down outside (I live in Colorado), I've been setting the temperature a bit higher (~70F) and have noticed that, when I do, the air flowing from the vents is much warmer than I'd expect.
While driving to work this morning, however, things got more complicated. I set the temperature to 70F only to have the heat itself kick in. The outside temperature at the time was 62F, but I was driving into direct morning sun, so it was warm enough inside the car that I wanted at least some cooling - not heat. Out of curiosity, I set the temperature even higher (~85F), and the air coming from the vents continued to increase in temperature. So, it wasn't like I was getting full heat at 70F. I continued to drive for awhile with the temperature set at 70F, and while the temperature of the air seemed to fluctuate some (there was a hint of cooling every so often), it remained warm until I got to the office.
So, my question... is this how automatic climate control systems work? Since the outside temperature at the time was 62F and the car had been sitting outside all night, I can only assume the ambient temperature of the cabin was no higher than 70F. By setting the temperature of the climate control to 75F, would it compensate by blowing hot air in order to bring the temperature up as quickly as possible?
For what it's worth, the owner's manual seemed to indicate that keeping the temperature at its lowest setting (65F) would result in maximum cooling, no matter what, and since that's where I've been keeping it until now, that would explain why I'm just now noticing this quirk... assuming it is a quirk, that is, and not a problem that needs servicing.
About a month ago, I bought a 2008 Subaru Forester. It's the first car I've owned that includes automatic climate control, and the owner's manual isn't particularly clear on how it works. I've been running it in "semi-automatic" mode, giving me greater control over settings, and since it's been hot lately and most of my driving is done during the day, I've almost always kept the temperature at its lowest setting (65F). However, now that's it's starting to cool down outside (I live in Colorado), I've been setting the temperature a bit higher (~70F) and have noticed that, when I do, the air flowing from the vents is much warmer than I'd expect.
While driving to work this morning, however, things got more complicated. I set the temperature to 70F only to have the heat itself kick in. The outside temperature at the time was 62F, but I was driving into direct morning sun, so it was warm enough inside the car that I wanted at least some cooling - not heat. Out of curiosity, I set the temperature even higher (~85F), and the air coming from the vents continued to increase in temperature. So, it wasn't like I was getting full heat at 70F. I continued to drive for awhile with the temperature set at 70F, and while the temperature of the air seemed to fluctuate some (there was a hint of cooling every so often), it remained warm until I got to the office.
So, my question... is this how automatic climate control systems work? Since the outside temperature at the time was 62F and the car had been sitting outside all night, I can only assume the ambient temperature of the cabin was no higher than 70F. By setting the temperature of the climate control to 75F, would it compensate by blowing hot air in order to bring the temperature up as quickly as possible?
For what it's worth, the owner's manual seemed to indicate that keeping the temperature at its lowest setting (65F) would result in maximum cooling, no matter what, and since that's where I've been keeping it until now, that would explain why I'm just now noticing this quirk... assuming it is a quirk, that is, and not a problem that needs servicing.
Does it show you the interior temperature? Because that's what it should be using to run the climate control, not the exterior temperature.
posted by smackfu at 8:08 AM on August 28, 2007
posted by smackfu at 8:08 AM on August 28, 2007
Response by poster: No, the interior temperature isn't displayed.
And Bonaldi, if I gradually increased the temperature setting, I would expect the temperature of the air to gradually moderate... not for it to immediately start blowing hot air. Basically, I'm trying to figure out if this is normal behavior or not.
posted by jal0021 at 8:17 AM on August 28, 2007
And Bonaldi, if I gradually increased the temperature setting, I would expect the temperature of the air to gradually moderate... not for it to immediately start blowing hot air. Basically, I'm trying to figure out if this is normal behavior or not.
posted by jal0021 at 8:17 AM on August 28, 2007
The automatic climate control acts pretty similarly in my 05 Mazda 6, so I think it's just the way the thing works. I have been adjusting manually since I find it's easier.
I, too, might just not understand the thing, though. I really haven't given it much thought since originally being confounded by it.
posted by boreddusty at 8:47 AM on August 28, 2007
I, too, might just not understand the thing, though. I really haven't given it much thought since originally being confounded by it.
posted by boreddusty at 8:47 AM on August 28, 2007
Best answer: My 2005 Legacy has the dual zone climate control. It is a weird and frustrating beastie. It is badly mechanized and it reacts both too rapidly and with too little damping.
Here is how it works, beginning from a push on the 'auto' button.
In 'auto' the control will attempt by many means to make the interior air temperature match what's set on the control, except if it is set at 65 - which means it will cool as much as possible - or 85, which means it will heat as much as possible. If you actuate the fan control, the A/C button or the mode button the automatic strategy will continue to try to reach the designated temperature while respecting the setting on the control you actuated (and the 'auto' indicator will go out).
The ACC takes account of solar load via the dime-sized black plastic gizzfratchet on the dash, and it measures the interior air temperature with a little air pump whose intake is - on my Legacy - near the driver's right knee. The temperature of that air is not displayed.
posted by jet_silver at 8:58 AM on August 28, 2007
Here is how it works, beginning from a push on the 'auto' button.
In 'auto' the control will attempt by many means to make the interior air temperature match what's set on the control, except if it is set at 65 - which means it will cool as much as possible - or 85, which means it will heat as much as possible. If you actuate the fan control, the A/C button or the mode button the automatic strategy will continue to try to reach the designated temperature while respecting the setting on the control you actuated (and the 'auto' indicator will go out).
The ACC takes account of solar load via the dime-sized black plastic gizzfratchet on the dash, and it measures the interior air temperature with a little air pump whose intake is - on my Legacy - near the driver's right knee. The temperature of that air is not displayed.
posted by jet_silver at 8:58 AM on August 28, 2007
Response by poster: It sounds like we have the same system, jet_silver (although mine is only single zone), and from your description of how it works, my guess as to what happened this morning is that the temperature control was set to auto, yet the fan was set to manual. Thus, that's why I got the blast furnace effect once the heat kicked on. Had I had the fan set to auto, I suspect it would have cut back enough to where the heat wouldn't have been all that noticeable.
I guess I'll have to play around with the various settings as the weather changes... the fact that you can set the various features to either auto or manual independent of each other makes for a variety of combinations. No wonder the owner's manual suggests setting everything to "auto" and being done with it.
posted by jal0021 at 12:09 PM on August 28, 2007
I guess I'll have to play around with the various settings as the weather changes... the fact that you can set the various features to either auto or manual independent of each other makes for a variety of combinations. No wonder the owner's manual suggests setting everything to "auto" and being done with it.
posted by jal0021 at 12:09 PM on August 28, 2007
This thread is closed to new comments.
posted by bonaldi at 7:55 AM on August 28, 2007