Automotive Air Conditioning Information Forum (Archives)

Provided by www.ACkits.com

We've updated our forums!
Click here to visit the new forum

Archive Home

Search Auto AC Forum Archives

How long untill i can press the re-circulate button

Blade on Wed August 05, 2009 12:59 PM User is offline

Model: 206
Country of Origin: United Kingdom

Hello

When i bought my car from the garage the only thing he didn't tell me was how to use the aircon.

So on a hot day how long should i have the blower going without the re-circulate on,Ive read having the re-circulate button pressed will get the car colder faster,So roughly how long should i be running it for? a couple of minutes or alot longer than that?

Thank You

NickD on Wed August 05, 2009 1:30 PM User is offline

Vehicle dependent question, back in the old days, the recir was a door that determined whether the incoming air source was either from the fresh air intake, that grille under the windshield, or from the interior of the vehicle. The switch would be 100%. Most vehicles limit the interior flow to 80% still getting the other 20% from the exterior. Common concern is building up the interior with CO that makes you kind of brain dead before killing you. Typically, your air will feel stuffy first. I get terrible headaches from CO especially in stalled traffic.

I love a manual recir door, comes in real handy when passing a farm with freshly dropped liquid manure or passing a paper mill. Also heats the car much quicker in subzero weather, but only for the first mile or so, windows start to fog. On really hot days on lonely country roads may leave it on all the time, far less load on the engine and still getting 20% of outside air. But if the interior gets way too dry, will switch it off. Am strapped in the seat, no place to go and the climate control is a finger touch away. So adjust it the way it feels most comfortable to you. If you start to yawn, time to switch it to outside air.

Blade on Wed August 05, 2009 1:36 PM User is offline

So then i can have it switched on as soon as i start the car? Or do i need to let in alot of cold air first,That is what i was really asking

Edited: Wed August 05, 2009 at 1:39 PM by Blade

iceman2555 on Wed August 05, 2009 3:04 PM User is offlineView users profile

Best cooling for an over heated vehicle is to operate the AC on NORM cool for the first few minutes. Allow the interior to begin to cool and then activate the REC mode. The system will only remove a certain amount of heat...if the cabin temp is warmer or hotter than the outside temp, it will take longer to cool the cabin. Lowering the windows will also aid in removal of heat from the cabin interior.
Most automatic AC systems will operate the system on NORM until the interior cabin temp equals the outside temp or is slightly cooler.

-------------------------
The strongest reason for the people to retain the right to keep and bear arms is, as a last resort, to protect themselves against tyranny in government.
Thomas Jefferson

Karl Hofmann on Wed August 05, 2009 7:09 PM User is offlineView users profile

In a UK Summer, the recirc facillity should never be needed.... The outside air is always cooler than the air in the cabin when you first start up.. extended use of the recirc wil result in the inside of your car becoming whiffy and stale... The only time I use it is when I find myself behind a vehicle that smokes more than it should or if there is a bonfire causing smoke to blow accross the path of my vehicle

-------------------------
Never knock on deaths door... Ring the doorbell and run away, death really hates that!

NickD on Wed August 05, 2009 11:08 PM User is offline

That's true here too if you leave your vehicle on a red hot asphalt parking lot in the midday sun closed up tighter than a drum, worse if you have a dark colored vehicle. Interior gets so hot you can bake a loaf of bread in it. Ours was that way last Sunday after we went kayaking, opened the doors for a few minutes before we even got in. Could fry an egg on the hood where the intake air is preheated before it gets into the vehicle. In weather like that, roll down the windows and drive a mile or so to cool it down even before switching on the AC, won't die. A simple test is to hold your hand in front of the vents with the AC on in both recir or fresh air intake and feel which is the coolest. But in our car, we never get full recir, only 80%, but again, if the air feels stuffy, switch to fresh air intake, switch is right there.

graeme on Sat August 22, 2009 5:15 AM User is offline

When to turn it to recirc?
As Nick has pointed out ^, if the car is out in the sun, then all the intake ducting from the plenum chamber gets very hot and typically takes quite a while to cool down. Of course there will be differences here between one car and the next. Relying on the car's auto climate control to switch to recirc when the car's interior temp drops below that of the exterior temp is flawed due to this, unless of course there is a sensor in the intake air, typically there is not and its relying on the car's exterior thermometer which is at the front of the car somewhere, perhaps there are some climate control systems that are sophisticated enough to measure inlet temp as well, dont know.
For this reason, I always put it on recirc when getting into a car left in the sun, the internal recirc flap usually goes fairly much direct to the evaporator, and wind the windows down to assist with getting some of the very hot air out, while having the vents pointing directly at me.
Ive approached this quite scientifically, putting sensors in plenum, aircon vents and cabin and found this is the quickest way to cool down the interior.
Ill only use straight through once the car has been underway for at least 15mins and if the exterior temp is lower than the temp Im trying to maintain in the car.

Ive also modified the flaps so that 100% recirc will be maintained and so far have not mananged to fall asleep due to lack of oxygen etc, I think enough air manages to seep into the cars as we drive them.

Edited: Sat August 22, 2009 at 5:35 AM by graeme

HECAT on Sat August 22, 2009 8:56 AM User is offline

Quote
Originally posted by: graeme
When to turn it to recirc?

I always put it on recirc when getting into a car left in the sun, the internal recirc flap usually goes fairly much direct to the evaporator, and wind the windows down to assist with getting some of the very hot air out, while having the vents pointing directly at me. Ive approached this quite scientifically, putting sensors in plenum, aircon vents and cabin and found this is the quickest way to cool down the interior.



There's your answer to when. Whenever it works the best.

With my cargo van (80% bare metal, no interior or insulation), I jump in "drippin" to the hot cabin from the afternoon sun bake (Atlanta, GA current avg 95 F @ 80% hum) and the air is set on max (recirc) and highest blower speed with all vents pointing at me. The far right vent remains closed as it cannot be directed at me (forcing all at me). The A/C controls are always preset and on-off is controlled with the key switch. I crack the window for a while and sometimes can stop "drippin within 10 minutes; but it usually takes about 20 to 30 minutes to begin to dry a shirt. Thats OE auto A/C as good as it gets, works for me.

-------------------------


HECAT: www.hecatinc.com You support the Forum when you consider www.ackits.com for your a/c parts.

FLUSHING TECHNICAL PAPER vs2.pdf 

Blade on Sat August 22, 2009 10:21 PM User is offline

Thank you everyone

I think i was not getting enough cool air into the car when it was sat in the sun,I was putting it on re-circulate to soon which meant it was pusing around the hot air which was hotter than the outside,I tried opening the windows a little longer than normal having it on normal aircon for longer seems to be the best way to push the hot air out then i just shut the window to start getting the car cool.

Edited: Sat August 22, 2009 at 10:21 PM by Blade

Back to Automotive Air Conditioning Forum

We've updated our forums!
Click here to visit the new forum

Archive Home

Copyright © 2016 Arizona Mobile Air Inc.