https://www.bbc.com/news/av/uk-engla...-on-school-run

How do you breathe less pollution on school run?

Families from Sheffield took part in a test to see who breathes in more pollution on the school run - kids who walk, bike or go by car.

The experiment saw three families take air quality monitors with them to school to measure levels of PM2.5, small particles of air pollution that are about 30 times thinner than a human hair.

Each method of transport was found to be over the World Health Organisation recommended safe limit, but which was the worst?

• 08 Oct 2019
  

 

Some cars have HEPA filters. Some Lexus models have a 'pollen and smog' button. Also the HS250h a few years ago had an Ionic air purifier.

 

In a luxury car (or almost any other vehicle) one can get at least some protection by simply hitting the air-recirculate button (or icon on the video-screen) for the climate control. That, in itself, cuts out a lot of the diesel fumes, tar/asphalt smells around construction areas, stench of water/sewage-treatment plants, pollen in the air, and other unpleasant or unwanted things coming into the vehicle.

 

Yup. This button saves my nose every time i drive up 295 and pass some sewage treatment/waste facility. Mostly i leave it on recirc.

 

In my car there's an option to turn on an allergen-reducing filter, which I typically use in the spring time to help reduce pollen. My allergies are terrible either way, but I would like to think it makes some kind of difference.

 

starting with the 1998 model year the LS got a smog sensor that automatically switches to recirc if high pollution levels are detected, so i'll be protected at least lol

 

Depends on if the windshield defrost is on or not. Using the windshield defrost automatically opens up the outside air intake to keep the moisture (and fogged-up windows) from being recirculated inside the car.

 

I love the automatic air recirculation in my GS. My Infiniti prior to the GS had this as well, though I feel that it works a bit better in the GS.

It's great when in traffic, whether on the street or freeway, when you're close to the exhaust of vehicles ahead of you/to the side of you, it switches to air recirculation mode. When traffic lets up or at speed, it lets fresh air in (assuming the air outside is clean enough, otherwise, it stays in recirc mode).

I don't usually ever notice foul odors entering the cabin in my GS. It seems to be able to detect them before I do and switch to recirc mode. In my Infiniti, I would notice the odors and then a few seconds after that I'd see the air recirc mode kick on.

 

That is incorrect. It is vehicle specific. My 4Runner is automatic and recirculation will open and close by itself in defrost mode. I can also select either or. But my Corolla and Corolla Matrix lock out the close feature.

 

For most vehicles, it is indeed correct. The automatic-fresh-air switch was implemented, more or less, a couple of decades ago, because people were turning on the windshield defrost, leaving the button in recirc-mode, and screwing up the inside of the windshield.

Recirc is ONLY to be used for rapid heat-up or cool-down in extreme temperatures, or if needed for short periods to keep out strong odors and air pollution. I sometimes flick it on if I'm close behind a diesel truck or bus....many of their powerlants don't have the same clean-diesel advances found in today's diesel cars (VW scandal notwithstanding LOL).

 

Still not correct. It is vehicle specific, at least for Toyota and Lexus cars. Like I said it locks out in my cars, does not lock out in my 4Runner. And depending on my AC setting, it will automatically stay locked in defrost mode.

This is actually incorrect again. My recirculating on button automatically defaults to the ON or closed position for my 4Runner, so if I want AC directed to the driver, it will always start in the ON setting. . Not the case for my cars. 4Runner also stays on when temp is 65 or lower. And a news flash for ya, your AC works better in recirculation mode and is more fuel efficient

 

4Runners do seem to do it a little differently than most other vehicles. The switch over is sometimes automatic, sometimes not. This, from page 290 of the 2019 4Runner Owner's Manual

https://www.toyota.com/t3Portal/docu...f/OM35B48U.pdf

1. Defogging the windshield
   Defoggers are used to defog the windshield and front side windows.
   
   The dehumidification function operates and fan speed increases.
   Set the outside/recirculated air mode button to the outside air mode if the recirculated air mode is used. (It may switch automatically.)
   To defog the windshield and the side windows early, turn the air flow and temperature up.

 

I am glad you can see you were incorrect as it is indeed vehicle specific 😃. I am sure this applies to almost all Lexus and upper Toyota models. Mine is 2004 BTW.

 

Well...not very much vehicle-specific. The vast majority of vehicles I've sampled do it automatically with the defrost. And, like I said, that was for safety reasons.

Decades ago, before that auto-switch function became (more or less) standard, I can remember people asking me "Mike, I'm using the defrost.....why won't the windshield clear?" 9 times out of 10, I would simply reach down, press the fresh air button, add a little bit of heat to the system to dry out the intake-air, give it about a minute or so, and......problem solved.

 

actually it depends on whether or not this button is in the auto position