JHZR2
Staff member
Just from autozone, but these seem pretty aggressive...
Deciphering AC vent temperatures
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I agree but I bet those numbers are reflecting "conditioned" air....recirculated, low humidity.
The numbers match my Cherokees test earlier within about 2 degrees.
The numbers match my Cherokees test earlier within about 2 degrees.
Originally Posted By: Merkava_4
You should have a 40F degree drop between outside temperature and vent temperature.
This has always been my minimum standard. Around here it is not uncommon to get 100+ ambient, you need cold air and lots of it!
I really think my vehicles with electric fans enjoy an advantage over my engine driven models.
And my lowly Chrysler has some of the best AC ever, not just for cold but for ease of operation. Jump in and start it up, you immediately get fresh outside air for about a minute or so then it switches to recirc and really gets excited. All automatically.
You should have a 40F degree drop between outside temperature and vent temperature.
This has always been my minimum standard. Around here it is not uncommon to get 100+ ambient, you need cold air and lots of it!
I really think my vehicles with electric fans enjoy an advantage over my engine driven models.
And my lowly Chrysler has some of the best AC ever, not just for cold but for ease of operation. Jump in and start it up, you immediately get fresh outside air for about a minute or so then it switches to recirc and really gets excited. All automatically.
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The only way to know for sure is to put a set of gauges on the system to see if it is indeed low on charge(BMW) and well obviously charge the 240D.
O and fix the re-circulation on the BMW and use it! From what I've read you should be able to hear & maybe to some degree feel/hear/see the flap being close. A motor whiring sound.
O and fix the re-circulation on the BMW and use it! From what I've read you should be able to hear & maybe to some degree feel/hear/see the flap being close. A motor whiring sound.
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Originally Posted By: SteveSRT8
Originally Posted By: Merkava_4
You should have a 40F degree drop between outside temperature and vent temperature.
This has always been my minimum standard. Around here it is not uncommon to get 100+ ambient, you need cold air and lots of it!
I really think my vehicles with electric fans enjoy an advantage over my engine driven models.
And my lowly Chrysler has some of the best AC ever, not just for cold but for ease of operation. Jump in and start it up, you immediately get fresh outside air for about a minute or so then it switches to recirc and really gets excited. All automatically.
Speaking personally, that is my fear with this Blazer 4.3. I had misremembered, and thought that it had electric cooling fans "that kick on at 220." This is further proof that my father did not know what he was talking about; as I now find out that it operates off of a fan clutch.
You would assume that a working fan clutch would make it cool properly, but on the "Lamborghini Aventador vs Rat Rod" episode (the Rat Rod had a 350SBC,) when idling in SoCal traffic, the 350SBC overheated, and overheated badly. Blew rap or hose before it came home, it was bad. That had a fan clutch, IIRC, but maybe the eccentric design of the Rat Rod had o air moving for cooling? Still, in traffic for a long time, I feel a fan clutch WOULD run hot/overheat, and the 4.3 is essentially a smaller SBC...
Electric fan vehicles, you could let it run all day, I'm sure.
Maybe old school fan clutch engines just don't cut it idling in traffic in heat, and that may be asking for trouble.
Unless, if it works properly, it's fine? Even when AC is on and it is 115-ish outside out?? ....
And in Death Valley and similar places (Miami?,) that means inside the car would be 80-90 degrees or so, with a 40-degree drop and AC on FULL BLAST....
Originally Posted By: Merkava_4
You should have a 40F degree drop between outside temperature and vent temperature.
This has always been my minimum standard. Around here it is not uncommon to get 100+ ambient, you need cold air and lots of it!
I really think my vehicles with electric fans enjoy an advantage over my engine driven models.
And my lowly Chrysler has some of the best AC ever, not just for cold but for ease of operation. Jump in and start it up, you immediately get fresh outside air for about a minute or so then it switches to recirc and really gets excited. All automatically.
Speaking personally, that is my fear with this Blazer 4.3. I had misremembered, and thought that it had electric cooling fans "that kick on at 220." This is further proof that my father did not know what he was talking about; as I now find out that it operates off of a fan clutch.
You would assume that a working fan clutch would make it cool properly, but on the "Lamborghini Aventador vs Rat Rod" episode (the Rat Rod had a 350SBC,) when idling in SoCal traffic, the 350SBC overheated, and overheated badly. Blew rap or hose before it came home, it was bad. That had a fan clutch, IIRC, but maybe the eccentric design of the Rat Rod had o air moving for cooling? Still, in traffic for a long time, I feel a fan clutch WOULD run hot/overheat, and the 4.3 is essentially a smaller SBC...
Electric fan vehicles, you could let it run all day, I'm sure.
Maybe old school fan clutch engines just don't cut it idling in traffic in heat, and that may be asking for trouble.
Unless, if it works properly, it's fine? Even when AC is on and it is 115-ish outside out?? ....
And in Death Valley and similar places (Miami?,) that means inside the car would be 80-90 degrees or so, with a 40-degree drop and AC on FULL BLAST....
I think i'm going to try this ignore feature, never used it before now.
Originally Posted By: spasm3
I think i'm going to try this ignore feature, never used it before now.
I don't use mine.
Since I can only assume that was @ me, for asking about clutch fans vs electric in AC.
I think i'm going to try this ignore feature, never used it before now.
I don't use mine.
Since I can only assume that was @ me, for asking about clutch fans vs electric in AC.
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Originally Posted By: default
Originally Posted By: spackard
Once I owned a '78 Chrysler Cordoba
With soft Corinthian leather?
No, cloth seats, light blue. It was bought used. Whatever happened to Montalban, or for that matter Linda Evans?
I got about 76F on max, recirculation in Death Valley, on a 118F day. There's too much heat out there. Plus, I was still running the remanufactured compressor, which didn't pump as much volume/work as well as my OEM compressor.
Originally Posted By: spackard
Once I owned a '78 Chrysler Cordoba
With soft Corinthian leather?
No, cloth seats, light blue. It was bought used. Whatever happened to Montalban, or for that matter Linda Evans?
I got about 76F on max, recirculation in Death Valley, on a 118F day. There's too much heat out there. Plus, I was still running the remanufactured compressor, which didn't pump as much volume/work as well as my OEM compressor.
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Originally Posted By: spackard
Originally Posted By: default
Originally Posted By: spackard
Once I owned a '78 Chrysler Cordoba
With soft Corinthian leather?
No, cloth seats, light blue. It was bought used. Whatever happened to Montalban, or for that matter Linda Evans?
SNL did a parody of this, i remember that.
Originally Posted By: default
Originally Posted By: spackard
Once I owned a '78 Chrysler Cordoba
With soft Corinthian leather?
No, cloth seats, light blue. It was bought used. Whatever happened to Montalban, or for that matter Linda Evans?
SNL did a parody of this, i remember that.
JHZR2
Staff member
Originally Posted By: Thermo1223
The only way to know for sure is to put a set of gauges on the system to see if it is indeed low on charge(BMW) and well obviously charge the 240D.
O and fix the re-circulation on the BMW and use it! From what I've read you should be able to hear & maybe to some degree feel/hear/see the flap being close. A motor whiring sound.
The BMW definitely isn't low on charge. But 134 in an r12 system can be finicky.
The only way to know for sure is to put a set of gauges on the system to see if it is indeed low on charge(BMW) and well obviously charge the 240D.
O and fix the re-circulation on the BMW and use it! From what I've read you should be able to hear & maybe to some degree feel/hear/see the flap being close. A motor whiring sound.
The BMW definitely isn't low on charge. But 134 in an r12 system can be finicky.
JHZR2
Staff member
At 76F and 95% humidity, it sure is comfortable driving in the 318. Plenty of dehumidification - needed to turn it down. Don't have my thermometer though which is a bummer. It's like a 35 mile drive this morning so it would've been ideal for measuring temperatures.
Originally Posted By: JHZR2
Originally Posted By: Thermo1223
The only way to know for sure is to put a set of gauges on the system to see if it is indeed low on charge(BMW) and well obviously charge the 240D.
O and fix the re-circulation on the BMW and use it! From what I've read you should be able to hear & maybe to some degree feel/hear/see the flap being close. A motor whiring sound.
The BMW definitely isn't low on charge. But 134 in an r12 system can be finicky.
Ya but how do you know? Putting a set of gauges on it is the only way.
Originally Posted By: Thermo1223
The only way to know for sure is to put a set of gauges on the system to see if it is indeed low on charge(BMW) and well obviously charge the 240D.
O and fix the re-circulation on the BMW and use it! From what I've read you should be able to hear & maybe to some degree feel/hear/see the flap being close. A motor whiring sound.
The BMW definitely isn't low on charge. But 134 in an r12 system can be finicky.
Ya but how do you know? Putting a set of gauges on it is the only way.
Also recirculation is in the 240D or should be based on the electrical schematics I was reading. Now as to how it is used & what does it I can't say for sure. I've read it is automatically called for when the A/C is used. However he climate system like most 80's ones are vacuum controlled so all I can say is good luck.
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Originally Posted By: JHZR2
Interesting... So for conditions like 86F with 57% humidity, my numbers are likely not all that bad... let alone when it was 94 with 50+% humidity.
94 deg F with 50% relative humidity is a dew point of 72.5 deg F. That's pretty dadgum warm and humid, and pretty tough to condition. You can cool 110 deg F desert air pretty well, because it's so dry. But the load of the moisture in east coast air is pretty taxing to an HVAC system.
Interesting... So for conditions like 86F with 57% humidity, my numbers are likely not all that bad... let alone when it was 94 with 50+% humidity.
94 deg F with 50% relative humidity is a dew point of 72.5 deg F. That's pretty dadgum warm and humid, and pretty tough to condition. You can cool 110 deg F desert air pretty well, because it's so dry. But the load of the moisture in east coast air is pretty taxing to an HVAC system.
Originally Posted By: TechnoLoGs
but maybe the eccentric design of the Rat Rod had o air moving for cooling?
This is the more likely reason for the overheat condition. If it's like most "rat rods", it uses an open radiator with no real cowl around the mechanical fan. This is very inefficient and when stopped, the fan will pull very little air through the radiator; it'll simply pull air from around the radiator...typical path of least resistance scenario.
This is why electric and mechanical fans both are hung very close to the radiator, and are usually cowled very well, at least in OEM applications.
You should have no concerns with your 4.3L V-6 in hot traffic conditions.
but maybe the eccentric design of the Rat Rod had o air moving for cooling?
This is the more likely reason for the overheat condition. If it's like most "rat rods", it uses an open radiator with no real cowl around the mechanical fan. This is very inefficient and when stopped, the fan will pull very little air through the radiator; it'll simply pull air from around the radiator...typical path of least resistance scenario.
This is why electric and mechanical fans both are hung very close to the radiator, and are usually cowled very well, at least in OEM applications.
You should have no concerns with your 4.3L V-6 in hot traffic conditions.
Originally Posted By: Hokiefyd
Originally Posted By: JHZR2
Interesting... So for conditions like 86F with 57% humidity, my numbers are likely not all that bad... let alone when it was 94 with 50+% humidity.
94 deg F with 50% relative humidity is a dew point of 72.5 deg F. That's pretty dadgum warm and humid, and pretty tough to condition. You can cool 110 deg F desert air pretty well, because it's so dry. But the load of the moisture in east coast air is pretty taxing to an HVAC system.
Our HVAC in the house is having trouble keeping it below 50% or at that sometimes. I have to lower the temp on the thermostat just to get that feeling out of the air. I don't need it that cold in the house but I would like it a little less humid.
A couple of nights the windows were collecting condensation on the outside because the A/C had to run just to keep the humidity in check. The effect was lowering temp in the house below the dew point.
The same applied to the cars as well, although the Jetta is more consistent since the compressor never shuts off.
Originally Posted By: JHZR2
Interesting... So for conditions like 86F with 57% humidity, my numbers are likely not all that bad... let alone when it was 94 with 50+% humidity.
94 deg F with 50% relative humidity is a dew point of 72.5 deg F. That's pretty dadgum warm and humid, and pretty tough to condition. You can cool 110 deg F desert air pretty well, because it's so dry. But the load of the moisture in east coast air is pretty taxing to an HVAC system.
Our HVAC in the house is having trouble keeping it below 50% or at that sometimes. I have to lower the temp on the thermostat just to get that feeling out of the air. I don't need it that cold in the house but I would like it a little less humid.
A couple of nights the windows were collecting condensation on the outside because the A/C had to run just to keep the humidity in check. The effect was lowering temp in the house below the dew point.
The same applied to the cars as well, although the Jetta is more consistent since the compressor never shuts off.
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Originally Posted By: Thermo1223
A couple of nights the windows were collecting condensation on the outside because the A/C had to run just to keep the humidity in check. The effect was lowering temp in the house below the dew point.
We have that condition here in the summertime on almost a daily basis... It's nothing for dew point to be 73*-75*F...
A couple of nights the windows were collecting condensation on the outside because the A/C had to run just to keep the humidity in check. The effect was lowering temp in the house below the dew point.
We have that condition here in the summertime on almost a daily basis... It's nothing for dew point to be 73*-75*F...
JHZR2
Staff member
What a difference a little r-12 made!!
And now the compressor cycles.
Granted its only 79F and 69%RH here today...
And now the compressor cycles.
Granted its only 79F and 69%RH here today...
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