AC / Recirc. question

[uberhahn]

Is here a way to decouple the recirculation from the AC? Does the compressor always come on, regardless of AC or Recirculation? Mine does.
In other vehicles, I was under the impression that the recirculation merely recirculated the cabin air.

[632 Regal]

The recirc function does use the compressor. I'm assuming its for short bouts through stinkville, but you dont want to leave it on forever either cause the air will get stale and possibly stinky post tacobell.


Is here a way to decouple the recirculation from the AC? Does the compressor always come on, regardless of AC or Recirculation? Mine does.
In other vehicles, I was under the impression that the recirculation merely recirculated the cabin air.

[genphreak]

I read BMW's reccomendation in the manual, but as I do a lot of city driving I use recirc most of the time. I find it never gets stinky, even if in the car for an hour.

But then again, unlike the BMW documentation gurus, I don't have a German diet.. :D

[uscharalph]

I read BMW's reccomendation in the manual, but as I do a lot of city driving I use recirc most of the time. I find it never gets stinky, even if in the car for an hour.

But then again, unlike the BMW documentation gurus, I don't have a German diet.. :D
What a smelly thread!

[genphreak]

What a smelly thread!ergh. I can imagine the next few posts... ok, bring on all the puns about a-holes driving BMWs... LOL

[Paul in NZ]

i thought that if you press the ac button again the a/c went off...
The manual says to avoid using recirc all the time.......

[SRR2]

I have a question for you: have an unusual number of first dates? ;-)

I can't stand being in a car without fresh air for more than a few minutes -- just long enough to drive through the Lincoln or Holland Tunnels is about right. And I can assure you that when, having not been given the choice, that getting in a car where the recirc has been on and occupied for a half-hour or more that it does indeed STINK. And it has nothing to do with methane emissions.

Moreover, I can't see one valid reason why anyone would not want fresh air. Doesn't make a lick of sense to me. Why would you or anyone want to breathe re-breathed air, with lower and lower O2 content and more and more CO2 content? Not to mention the additional moisture and smell? Doesn't make a damn bit of sense, despite the occasional stinking bus. For that, I'd use recirc temporarily.

You know... quality of ventilation was one of the factors that finally pushed me over the edge to get rid of the ('89 -- sans pollen filter) E34 I had, and move into an E39. Those charcoal filters are almost too good to be true. The first exposure I had to them was when I got the Porsche which came standard with the charcoal filter. I soon discovered that stinky buses or sewage treatment plants just didn't smell as bad as they used to. In fact, they barely smelled at all. When I saw the user-friendly filter arrangement in the E39 I was sold. I've even driven through the tunnels without turning on recirc and without being gassed out.

Fresh air and charcoal filters ...

[genphreak]

I have a question for you: have an unusual number of first dates? ;-)

I can't stand being in a car without fresh air for more than a few minutes -- just long enough to drive through the Lincoln or Holland Tunnels is about right. And I can assure you that when, having not been given the choice, that getting in a car where the recirc has been on and occupied for a half-hour or more that it does indeed STINK. And it has nothing to do with methane emissions.

Moreover, I can't see one valid reason why anyone would not want fresh air. Doesn't make a lick of sense to me. Why would you or anyone want to breathe re-breathed air, with lower and lower O2 content and more and more CO2 content? Not to mention the additional moisture and smell? Doesn't make a damn bit of sense, despite the occasional stinking bus. For that, I'd use recirc temporarily.

You know... quality of ventilation was one of the factors that finally pushed me over the edge to get rid of the ('89 -- sans pollen filter) E34 I had, and move into an E39. Those charcoal filters are almost too good to be true. The first exposure I had to them was when I got the Porsche which came standard with the charcoal filter. I soon discovered that stinky buses or sewage treatment plants just didn't smell as bad as they used to. In fact, they barely smelled at all. When I saw the user-friendly filter arrangement in the E39 I was sold. I've even driven through the tunnels without turning on recirc and without being gassed out.

Fresh air and charcoal filters ...:D I don't get that in my car. Perhaps I just don't stink... no seriously, I feel as such. And my sense of smell isn't that bad. I have no reason to go from a recirc condition to fresh... but in Australia there are no rules taht make people maintatin their emission systems so traffic is by far smellier than in other western countries, and given the inherrent dangers associated with breathing the toxic soup we as Aussies enjoy bathing in when on the road I choose recirc more than fresh.

However on reflection I do use fresh, in fact I do quite often, though never with the A/C on. I find the A/C keeps the car smelling good- and has done on most of my cars (except the others were mostly new). This car has never been owned by a smoker so that might be one reason- perhaps that contaminates the condenser with a substrate of dust that can support a good population of bacteria. In many cars I'm amongst the first to smell it too.

I never run the A/C on short trips though and always stabilise the temperature of the car for 5 mins before turning it on. That could be another reason.. or maybe I just can't smell... but I don't have a problem keeping my dates! :) Nick

For what its worth I am even considering retrofitting a pollen filter (that's how much I hate smells).. so I appreciate your decision to go e39.

[SRR2]

Not to beat the dead horse, but the occupants of a closed-up car have time to acclimate to the moisture and smell. A newcomer, believe me, is not acclimated and does notice both!

I'm sorry to hear about the emissions situation in Oz. I'm old enough to remember the foul atmosphere on the road before emissions controls here. It was not at all pleasant. The smell of unburned gasoline coming out all those tailpipes was often bad enough to soak into your clothes and hair. Driving through enclosed areas, such as the aforementioned tunnels, was the stuff of nightmares. They couldn't pump outside air through the tunnel ventilation anywhere near the rate necessary to prevent the toxic soup from forming. Now, in all honesty, they're not too bad. You can drive down the roads here now and basically not smell any exhaust at all. You can put me in the "Strongly Favors Emission Controls" column for sure, and I have no use for people who ramrod their cats and perpetrate other similar antisocial behavior.

Looking back at the late 60s and 70s when the oil "crisis" hit and the Clean Air Act (One of Nixon's prouder moments. Today's "conservatives" make him look almost human.) was taking effect, every car company bitched loud and long about how the new standards were "impossible", they'd add $10000 to the cost of every car, and that fuel economy would fall 50%. It was the same song and dance they spewed when seat belts were mandated, and then later airbags. Basically, it destroyed their credibility concerning safety and performance mandates. So, as we all know, it turned out pretty well. Cars now run clean, they're as powerful as those before emission controls existed, and they get 50% better fuel mileage. And why is this? Because the Federal Governement stuck to their guns and ignored the high-paid lobbyists. Can you freaking imagine that happening now? Yah, right.

[Blitzkrieg Bob]

Especially when you are in hot & humid climates is takes less BTUs to cool just a cabin full of air verses hot, humid fresh air.

As far as running out if O2, I don’t think the car is that air tight that you’d run the risk of blacking out.

If the A/C gets stinky, it is usually because the evaporator chamber is growing mold and mildew from all the condensation in there. Just give it a spray of Ozium or something now and then, and run the HVAC system through all the functions regulary to help keep it clear.

[SRR2]

If you're pointing the comment about the O2 at me, I never said anything about blacking out, but you CAN get sleepy with O2 reduction and CO2 buildup. Agreed about extreme cooling situations, of course, but even so, it's still a good idea to bring in a charge of fresh air once in a while.

[genphreak]

Heh, true SRR2.

I hear you on the aclimitsation aspect, but AC pong goes beyond the pale. Somehow mine avoids it. If someone farts however... LOL different story. Maybe we have evolved to get used to rising methane levels in shared caves at night. ROFL.

Yes indeed the lack of Environmental Protection regulations here sucks- its just part of our dumbass Island mentality. Our traffic pollution is apalling. We don't have the sustained traffic densities due to a more spread out and smaller population level (over this sparse continent), so its never coming up as a political issue.

It just pisses me off to smell cars (esp. Mazdas and other cheap asian-engined yoghurt cartons) going round belching awful fumes after less than half their usable life.

Perhaps cancer levels will reduce our reliance on fossil fuels before we do...