In answer to the query about vent temperatures, which may not have been directed to me:
They vary depending on many factors. Ambient temperatures here in the summer typically run in the 80s or 90s, and when i'm using the AC in such conditions the vent temperatures typically run between 40 and 50 degrees F. I can get temperatures lower than that, but then it gets too cold inside the car. When ambient temperatures get up to 110 degrees or so F, vent temperatures may run between 50 and 55 degrees F. The temperatures rise a little bit when the car is not moving.
But it's a mistake to focus too much on vent temperatures. What you want to know is how much heat the system is capable of removing from the air, and that depends on a lot more than just the vent temperatures. A major factor is how much air is moving at those temperatures, and there's no easy way to determine that. I disagree with one of Frank Beck's statements about the factory Behr system: "Inefficient evaporator and too far away from the dash vents." In my experience, that's simply not the case. I did replace the evaporator with a more efficient one, using the original evaporator housing, but I have no reason to doubt that the original one would have been capable of reasonable performance. Ialso question his statement: "Evap fan is inefficient causing low volume." I also replaced the evaporator fan motor with one that moved a little more air, but the difference in airflow is not that great.
The AC is a system intended to produce a subjective result, comfort. So as long as it does that, I think that there's no reason to fixate on vent temperatures (although, because i'm an engineer, I have a hard-to-break habit of p[aying attention to such things).
So I'll provide you with some subjeective information. When the car sits outside in the sun and the ambient temperature is above 100 degrees F, the interior of the car gets pretty hot pretty fast (I rarely do this, but it has happened on occasion). Running at maximum capacity, the AC can make the interior of the car tolerable in no more that about 5 minutes, and get it down to a temperature that we would choose in about another 5 minutes. It works better than the AC in my 993. My wife thinks it works better than the AC in her Boxster. I think that's a bit of an exaggeration, but if she's happy, I'm happy.
As to the comment about two many components increasing the chance of leaks, the system was last charged about 2.5 years ago. I suspect that it has lost some refrigerant over that period of time, but just last week we had temperatures well above 100 degrees and the system worked quite well, so whatever loss of frean that might have occurred must have been relatively small, not enough to affect performance significantly. I'm not sure that the additional components are more of a factor than the fact that the system has about 40 feet of barrier hose, but that appears to be working well.
Someone commented on getting rid of the condenser under the rear deck lid grill. I thought about that at the time I was deciding how to configure the system, but ultimately decided not to do that, in par on the basis of Grif's recommendation. The compressor feeds freon to the condensers in the following order: rear deck lid, condenser behind the left rear wheel, condenser in front of the left rear wheel, condenser under the nose. And then, of course, to the receiver dryer and the evaporator. Feeding the rear wheel well condensers first, then the rear deck lid condenser, might mitigate, under some circumstances, the extra heat added to the air coming in through the grill, but it wouldn't do that when it counts the most, when ambient temperatures are highest, and it would require even a little more hose. In any event, with the external oil cooler, which is a good idea anyway, it's not a problem.
It may be that someone can make a system with only two condensers that works as well as this, but I'm skeptical. In any event, I've been pleased with the way this has worked out and would recommend the Griffiths system. It's well thought out, the components are of high quality and the support from Griffiths is excellent. It also makes good use of various components of the old Behr system and requires no modifications to the car.
They vary depending on many factors. Ambient temperatures here in the summer typically run in the 80s or 90s, and when i'm using the AC in such conditions the vent temperatures typically run between 40 and 50 degrees F. I can get temperatures lower than that, but then it gets too cold inside the car. When ambient temperatures get up to 110 degrees or so F, vent temperatures may run between 50 and 55 degrees F. The temperatures rise a little bit when the car is not moving.
But it's a mistake to focus too much on vent temperatures. What you want to know is how much heat the system is capable of removing from the air, and that depends on a lot more than just the vent temperatures. A major factor is how much air is moving at those temperatures, and there's no easy way to determine that. I disagree with one of Frank Beck's statements about the factory Behr system: "Inefficient evaporator and too far away from the dash vents." In my experience, that's simply not the case. I did replace the evaporator with a more efficient one, using the original evaporator housing, but I have no reason to doubt that the original one would have been capable of reasonable performance. Ialso question his statement: "Evap fan is inefficient causing low volume." I also replaced the evaporator fan motor with one that moved a little more air, but the difference in airflow is not that great.
The AC is a system intended to produce a subjective result, comfort. So as long as it does that, I think that there's no reason to fixate on vent temperatures (although, because i'm an engineer, I have a hard-to-break habit of p[aying attention to such things).
So I'll provide you with some subjeective information. When the car sits outside in the sun and the ambient temperature is above 100 degrees F, the interior of the car gets pretty hot pretty fast (I rarely do this, but it has happened on occasion). Running at maximum capacity, the AC can make the interior of the car tolerable in no more that about 5 minutes, and get it down to a temperature that we would choose in about another 5 minutes. It works better than the AC in my 993. My wife thinks it works better than the AC in her Boxster. I think that's a bit of an exaggeration, but if she's happy, I'm happy.
As to the comment about two many components increasing the chance of leaks, the system was last charged about 2.5 years ago. I suspect that it has lost some refrigerant over that period of time, but just last week we had temperatures well above 100 degrees and the system worked quite well, so whatever loss of frean that might have occurred must have been relatively small, not enough to affect performance significantly. I'm not sure that the additional components are more of a factor than the fact that the system has about 40 feet of barrier hose, but that appears to be working well.
Someone commented on getting rid of the condenser under the rear deck lid grill. I thought about that at the time I was deciding how to configure the system, but ultimately decided not to do that, in par on the basis of Grif's recommendation. The compressor feeds freon to the condensers in the following order: rear deck lid, condenser behind the left rear wheel, condenser in front of the left rear wheel, condenser under the nose. And then, of course, to the receiver dryer and the evaporator. Feeding the rear wheel well condensers first, then the rear deck lid condenser, might mitigate, under some circumstances, the extra heat added to the air coming in through the grill, but it wouldn't do that when it counts the most, when ambient temperatures are highest, and it would require even a little more hose. In any event, with the external oil cooler, which is a good idea anyway, it's not a problem.
It may be that someone can make a system with only two condensers that works as well as this, but I'm skeptical. In any event, I've been pleased with the way this has worked out and would recommend the Griffiths system. It's well thought out, the components are of high quality and the support from Griffiths is excellent. It also makes good use of various components of the old Behr system and requires no modifications to the car.
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