True or false: Let windows down to speed up AC?

[TechnoLoGs]

Well, seeing as how today is still a super nice one, I turned on the AC. I may need a recharge, I am unsure. It is slightly weak, and I have no idea if mine was retrofitted or not. And from what I recall, R12 is priced similarly to gold. Please correct me if I am wrong. (Tell me where in NNJ I can get the AC serviced honestly and without getting taken for a ride, and I will go there. I would be tempted to recharge my own with the cans they sell in the store, but that stuff is R134a IIRC, so I am not sure if it will work. Someone told me it will, the only difference is the connectors. Liek i said, I am unsure so I should leave it alone. I have otgher things to wrench on.)

In any case, let's talk about this point, long since passed down: When you turn ont he AC, you let the windows down, to get it going. True or false?

And yes, I know usign the AC taxes small engines something awful.. not really worried about that since the engine I have is pretty big. Still, I remember how the saying of how AC on the highway (as opposed to the windows down, load on engine vs drag and wind from windows) won't really hurt gas mileage was proven false on a number of vehicles. That is a separate discussion, I suppose.

 

[Mr Nice]

No.

 

[440Magnum]

Originally Posted By: TechnoLoGs


In any case, let's talk about this point, long since passed down: When you turn ont he AC, you let the windows down, to get it going. True or false?



My normal AC startup procedure in the hottest part of Texas summer is:

1) Get in 150-degree-plus car and start it as fast as possible
2)HVAC on FRESH air, highest fan speed with a window cracked open until the 150-degree-plus air is mostly exchanged out (usually about a minute or two tops, I usually let it do that while I'm taking down my window sun shield, buckling up, etc).
3) HVAC on RECIRCULATE, highest fan speed, with windows closed as soon as possible.

 

[EricF]

I say false.

When the A/C is on, it's on. it starts circulating freon and the cold air begins to form and flow out the vents based upon where the hot/cold diverter is.

If you aren't getting the air you're expecting, check the low-side pressure.. system could be a bit low, or worse.. partially plugged orifice tube maybe..

 

[jrustles]

If the inside of the car is hotter than outside, then yea. Crack the windows open and the excess heat just spills up and out

 

[jrustles]

Techno, it does seem like you need a charge. If you really wanted to, you could easily recharge your system withone of the "green" hydrocarbon refrigerants, and it mixes fine with the 134, actually increasing efficiency. The result will be a zeotropic refrigerant blend and will increase the 'temperature glide' of the charge. I personally am not too concerned about flammability concerns of hydrocarbon refrigerants primarily based on an evident history of very low incidence, and also because 134 is flammable also, but when it burns it produces lethal phosgene gas! The industry won't tell you that!

Either way, the Fluoro- component of the HFC 134 molecule is the active fire retardant agent, and doesn't stop working just because there are other hydrocarbon gasses present.

 

[JHZR2]

R12 has come way down in price, so if your vehicle is designed for R12, Id keep it. The pressures in the system will be lower which is a good thing.

Ive done a few retrofits, and if done well, they work fine and dont leak. But depending upon compressor design, vehicle state, etc., it may not be smart. And again, with the price of R12 coming down, Id give it a good look, it will cool better than a retrofit system.

Audios on here is in Lyndhurst on Park Ave. I know they do good work, but I dont know if they do R12 or auto AC at all. He may be a good person at least for a reference.

As for opening windows, just use common sense... there is a lot more heat energy in 130F air than in 80F air. That heat energy either needs to be removed via the freon in the AC system, or else replaced with cooler air from outside or both. Swapping the cooler air by opening the windows means that there is less total energy to remove from the air in the cabin, which means that the air will feel comfortably cooler, faster.

Now that said, if youre hot, the car is hot and the surfaces are hot, outside air may not feel as comfortable as refrigerated air at 40F. So some may argue from a first-person comfort point of view, which is valid.

But if you can exchange hot air for cooler air, it is a good thing...

 

[Rock_Hudstone]

Originally Posted By: TechnoLoGs
(Tell me where in NNJ I can get the AC serviced honestly and without getting taken for a ride, and I will go there.

I would recommend my mechanic, super honest and knowledgeable,

However, he is in Whippany on Rt.10 and you're in North Bergen, not that far, but you may take the easy way out, use a local guy and get fleeced..

 

[TechnoLoGs]

Originally Posted By: JHZR2
R12 has come way down in price, so if your vehicle is designed for R12, Id keep it. The pressures in the system will be lower which is a good thing.

Ive done a few retrofits, and if done well, they work fine and dont leak. But depending upon compressor design, vehicle state, etc., it may not be smart. And again, with the price of R12 coming down, Id give it a good look, it will cool better than a retrofit system.

Audios on here is in Lyndhurst on Park Ave. I know they do good work, but I dont know if they do R12 or auto AC at all. He may be a good person at least for a reference.

As for opening windows, just use common sense... there is a lot more heat energy in 130F air than in 80F air. That heat energy either needs to be removed via the freon in the AC system, or else replaced with cooler air from outside or both. Swapping the cooler air by opening the windows means that there is less total energy to remove from the air in the cabin, which means that the air will feel comfortably cooler, faster.

Now that said, if youre hot, the car is hot and the surfaces are hot, outside air may not feel as comfortable as refrigerated air at 40F. So some may argue from a first-person comfort point of view, which is valid.

But if you can exchange hot air for cooler air, it is a good thing...


I used to work in Lyndhurst.

Yes, after I get soem of my other issues licked, I may very well take it there.. going to be a HOT summer and I suspect my AC is undercharged.

I also agree, I think the letting windows down to get air out is common senseworthy. However, I think they erred when they seemed to suggest that the AC would "get going" by "leaving the window open just a crack," akin to vacuum...

I think my truck has those leather seats that burn you in the summer they get so hot. Unsure, I haven't experienced it yet, and the seats seem softer than others I have seen with black leather (my leather is tan and more cushy, though not a Cadillac.)

 

[TechnoLoGs]

Originally Posted By: Rock_Hudstone
Originally Posted By: TechnoLoGs
(Tell me where in NNJ I can get the AC serviced honestly and without getting taken for a ride, and I will go there.

I would recommend my mechanic, super honest and knowledgeable,

However, he is in Whippany on Rt.10 and you're in North Bergen, not that far, but you may take the easy way out, use a local guy and get fleeced..

Just saw this.

How close to Rt 46 intersection of Rt. 10 in Denville?

 

[TechnoLoGs]

Originally Posted By: jrustles
Techno, it does seem like you need a charge. If you really wanted to, you could easily recharge your system withone of the "green" hydrocarbon refrigerants, and it mixes fine with the 134, actually increasing efficiency. The result will be a zeotropic refrigerant blend and will increase the 'temperature glide' of the charge. I personally am not too concerned about flammability concerns of hydrocarbon refrigerants primarily based on an evident history of very low incidence, and also because 134 is flammable also, but when it burns it produces lethal phosgene gas! The industry won't tell you that!

Either way, the Fluoro- component of the HFC 134 molecule is the active fire retardant agent, and doesn't stop working just because there are other hydrocarbon gasses present.


Are you saying I can buy the $25 can from the store, hook it up with conenctors I can get to fit somehow and charge it into the low-side port and NOT blow anything up?

 

[JHZR2]

Originally Posted By: jrustles
Techno, it does seem like you need a charge. If you really wanted to, you could easily recharge your system withone of the "green" hydrocarbon refrigerants, and it mixes fine with the 134, actually increasing efficiency. The result will be a zeotropic refrigerant blend and will increase the 'temperature glide' of the charge. I personally am not too concerned about flammability concerns of hydrocarbon refrigerants primarily based on an evident history of very low incidence, and also because 134 is flammable also, but when it burns it produces lethal phosgene gas! The industry won't tell you that!

Either way, the Fluoro- component of the HFC 134 molecule is the active fire retardant agent, and doesn't stop working just because there are other hydrocarbon gasses present.


You dont know that he has 134a, making mixes is illegal and may prevent him from being able to have his vehicle worked on.

Some of the blends may work well, but he needs to know what issues he is dealing with first.

Do you even know what an azeotrope is?

 

[Rock_Hudstone]

Originally Posted By: TechnoLoGs
Originally Posted By: Rock_Hudstone
Originally Posted By: TechnoLoGs
(Tell me where in NNJ I can get the AC serviced honestly and without getting taken for a ride, and I will go there.

I would recommend my mechanic, super honest and knowledgeable,

However, he is in Whippany on Rt.10 and you're in North Bergen, not that far, but you may take the easy way out, use a local guy and get fleeced..

Just saw this.

How close to Rt 46 intersection of Rt. 10 in Denville?

No, they are just south of Rt. 287 on 10 west.

http://www.rumbelloautorepair.com/

 

[yonyon]

Originally Posted By: JHZR2

Do you even know what an azeotrope is?


Isn't that what they charge you with when you steal something like this

from a zoo and boil it?

 

[jrustles]

Originally Posted By: TechnoLoGs

Are you saying I can buy the $25 can from the store, hook it up with conenctors I can get to fit somehow and charge it into the low-side port and NOT blow anything up?


Yes. If you have R12, you'll have standard shraeder valves. You'll need a readily available adapter if that's the case. I should have mentioned that HC refrigerants (those cans) work with both 134 and 12. Just know what kind of charge pressure you're looking for and do exactly what you described. You don't need to be a AC technician to do that, just competent. Try shooting for ~55psi on the low side/1500rpm. Depending on how long it's been since it was last serviced (since factory?) I'd charge 1-2oz PAO at the appropriate grade, but you probably shouldn't worry about it.

Originally Posted By: JHZR2


You dont know that he has 134a, making mixes is illegal and may prevent him from being able to have his vehicle worked on.


due to red tape, diplomacy and politics.

Quote:

Do you even know what an azeotrope is?


Yes, an azeotrope or 'azeotropic mixture' is the opposite of the zeotropic mixture that I was describing in my post

 

[Quattro Pete]

Originally Posted By: TechnoLoGs
In any case, let's talk about this point, long since passed down: When you turn ont he AC, you let the windows down, to get it going. True or false?

False. But if your car has been sitting out in the sun and it's a sauna oin there, opening up the windows for a little bit is useful. It does not help the AC "get going" but it helps evacuate the hot air quicker. There is a lot more air flow when the wind blows through your car's windows than the car's HVAC can deliver.

 

[Darren270]

Quote:
When you turn ont he AC, you let the windows down, to get it going. True or false?


I'm gonna say false also. However, I do put the windows down first, AC off, while driving just to evacuate the heat first. After a few minutes, roll up windows, crank AC on. Once it gets cool/cold inside, turn to recirculate.

As for recharging an R12 system with 134a, just to throw it out there, about 12-13 years ago Car Craft magazine did an article on a 1988 Pontiac Firebird they were fixing up. They filled it with R134a instead of R12, and in their own words "...nothing blew up and the AC now blows like winter."

 

[SteveSRT8]

Here in Florida I have seen interior temps well over 130 degrees on a hot summer day!

You must roll the windows down, but only for a minute or so.

Our car will automatically select outside air for the first couple of minutes and then switches to recirculate.

 

[NHHEMI]

Originally Posted By: jrustles
If the inside of the car is hotter than outside, then yea. Crack the windows open and the excess heat just spills up and out

Agreed. Cracking the windows when the inside air is hotter than the outside air absolutely speeds up the AC cooling the interior down.

 

[TFB1]

Originally Posted By: JHZR2
Originally Posted By: jrustles
Techno, it does seem like you need a charge. If you really wanted to, you could easily recharge your system withone of the "green" hydrocarbon refrigerants, and it mixes fine with the 134, actually increasing efficiency. The result will be a zeotropic refrigerant blend and will increase the 'temperature glide' of the charge. I personally am not too concerned about flammability concerns of hydrocarbon refrigerants primarily based on an evident history of very low incidence, and also because 134 is flammable also, but when it burns it produces lethal phosgene gas! The industry won't tell you that!

Either way, the Fluoro- component of the HFC 134 molecule is the active fire retardant agent, and doesn't stop working just because there are other hydrocarbon gasses present.


You dont know that he has 134a, making mixes is illegal and may prevent him from being able to have his vehicle worked on.

Some of the blends may work well, but he needs to know what issues he is dealing with first.

Do you even know what an azeotrope is?


This ^^^^^^^^^

You absolutely do NOT want to mix R12 & R134, plus a 12 system should NEVER have 134 installed unless the system is first flushed of the mineral oil used in those...

Yeah you can can kludge one with the wrong refrigerant and it will work for awhile but the incompatibly between the oil and refrigerant will come back to bite you...

If its a 134 system then disregard my post...