I am hoping that someone can help me regarding the correct amount of refrigerant to add to a TZD Turbo system (Sanden 709) compressor (or point me in the right direction.
I retro-fitted the system last year and had it gassed up with RS24 by a local firm shortly afterwards. The system works but perhaps not as well as it did last year. I have not measured the temperature at the vents this year but after filling it was about 7 degrees C which I believe may be a little on the warm side???
So I am thinking of having it re-gassed, but not with the same people as they didn't seem to measure the charge that was added (they just connected up and opened the valve on the bottle), and I understand that the amount put in the system is critical to efficient operation.
Does anyone have a figure for how much should be put in? Or should any reputable outfit have a chart showing the aounts for different cars? Or is it not that important?
Air con refrigerant capacity
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mat_fenwick
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AlanS
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Whoops just spotted this.
RS24 I haven't encountered and as there is a different measure for a variety of refrigerants due to their densities, I can only give you a guesstimate.
If its properties are the same as R134a then it will take 800 grams. MP52 will be 1 kg and if you use "greenfreeze" (a.k.a. "Hychill minus 30) it will take only 300 grams.
As a guide, look at the sight glass on the top of the receiver/dryer when the system is running and if it is just hazey looking, it should be OK. If there appears to be large bubbles then it's low on gas and if there's absolutely no sign of any movement when the air/con is activated, then it's bone dry.
Incidentally, if it was only charged last summer and has already dumped the charge, regassing is a waste of time and money if you don't find the leak.
Take a close look at all the joints and look for what appears to be oil stains. Chances are you have an "O" ring or two whch are failing to seal properly and must be replaced.
Alan S
RS24 I haven't encountered and as there is a different measure for a variety of refrigerants due to their densities, I can only give you a guesstimate.
If its properties are the same as R134a then it will take 800 grams. MP52 will be 1 kg and if you use "greenfreeze" (a.k.a. "Hychill minus 30) it will take only 300 grams.
As a guide, look at the sight glass on the top of the receiver/dryer when the system is running and if it is just hazey looking, it should be OK. If there appears to be large bubbles then it's low on gas and if there's absolutely no sign of any movement when the air/con is activated, then it's bone dry.
Incidentally, if it was only charged last summer and has already dumped the charge, regassing is a waste of time and money if you don't find the leak.
Take a close look at all the joints and look for what appears to be oil stains. Chances are you have an "O" ring or two whch are failing to seal properly and must be replaced.
Alan S
By the time you're old enough to know it all, you can't remember why you were learning.
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AlanS
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Matt,
I also meant to comment on the compressor you have fitted, a Sanden 709. This is the compressor from a BX16V and is designed to drive at 6000 rpm with a downshift capacity of 8000. The 509 which is often fitted to the 8 valve models and I would presume diesels, runs 4000 & 6000 respectively. It also runs a somewhat different condensor mainly due to places where it will fit; whether this has any bearing on performance I can't say, however for what it's worth, there is a member here who is wanting to fit air to his 16V but has one of the 8 valve systems which I would reckon would also be similar to the ones they fit to the diesels.
As a suggestion, can I suggest you send him a PM and see if you can both end up with a more suitable scenario than exists at present.
The member is "prm" a member of long standing. I don't know where he is goegraphically in regards to your location, but as you need to rectify a leak, no time like the present to kill 2 birds with the one stone. It might also explain why you had those spacers off the mounts on your car that didn't seem to fit when the 709 was installed and will be needed by the one using the 709 but possibly not by anyone using a 500 compressor due to mounting lug locations.
Alan S
I also meant to comment on the compressor you have fitted, a Sanden 709. This is the compressor from a BX16V and is designed to drive at 6000 rpm with a downshift capacity of 8000. The 509 which is often fitted to the 8 valve models and I would presume diesels, runs 4000 & 6000 respectively. It also runs a somewhat different condensor mainly due to places where it will fit; whether this has any bearing on performance I can't say, however for what it's worth, there is a member here who is wanting to fit air to his 16V but has one of the 8 valve systems which I would reckon would also be similar to the ones they fit to the diesels.
As a suggestion, can I suggest you send him a PM and see if you can both end up with a more suitable scenario than exists at present.
The member is "prm" a member of long standing. I don't know where he is goegraphically in regards to your location, but as you need to rectify a leak, no time like the present to kill 2 birds with the one stone. It might also explain why you had those spacers off the mounts on your car that didn't seem to fit when the 709 was installed and will be needed by the one using the 709 but possibly not by anyone using a 500 compressor due to mounting lug locations.
Alan S
By the time you're old enough to know it all, you can't remember why you were learning.
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mat_fenwick
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Thanks for the information Alan. I'm not certain whether I do actually have a leak as it is only a suspicion that the air isn't as cold as last year. It is still uncomfortable to hold my hand in front of it so I may be worrying about nothing. All the O rings were replaced with the green (neoprene?) ones when re-installing the system. However I do wonder whether I should be seeing lower than 7 degrees anyway - which if I have a compressor from a 16v could explain things!
On my R/D there is no sight glass so I cannot check for bubbles etc. If I have to open up the system then I may as well take the opportunity to replace it again (was replaced last year when it was first charged). The system was left open for some months before installation so the dessicant in the R/D may be 'spent' removing any moisture present when it was first put in the system, am I right?
On my R/D there is no sight glass so I cannot check for bubbles etc. If I have to open up the system then I may as well take the opportunity to replace it again (was replaced last year when it was first charged). The system was left open for some months before installation so the dessicant in the R/D may be 'spent' removing any moisture present when it was first put in the system, am I right?
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AlanS
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Going on feel may not be a good guide as a comparison between last year and this.
With this mad weather we've got over here, I'm still running my air/con (winter officially starts in just over a week) as we are still getting above 30 degree days, but the morning temps are sometimes down a bit, into the teens, so as a result we aren't getting the high humidity and as a result, mine also feel a bit warmer than normal to me, yet I have passengers complaining about how cold they are.
We used to work on a temp at the vent of between 38 & 42, so in todays lingo, that's 3.33 to 5.55 C. so you are at the upper end of the scale.
It seems that the actual specs for these car air/con compressors is usually shrouded in mystery, so whilst they don't give an actual capacity, it is fair to guess that their capacity is in some ways connected to their designed running speed as with some marine applications I've been involved with, however, it should be in the ball park given the lesser load it would have to contend with over there, it's just that it would possibly be moe efficient with the other one particularly if you are running a condensor off an 8 valve system.
With the knowledge that the system was open for a prolonged period, you may have a good point with the possibility that the receiver dryer may have gone past its use by date as I have heard of some of these BX systems that have been contaminated being clagged up inside with a black gooey stuff that takes some shifting, so a really long pump out with a vacuum pump couples with a couple of flushes and possibly a new filter dryer might be a good move.
Latest trick out here to flush them out is they use LPG. Yep, same stuff that you use in the barbeque.
It was used as a refrigerant donkeys years ago and is apparently compatable with all the oils, O rings, seals and gasses and costs peanuts. Was dropped many years ago due to its volatility so don't light up while it's being used, but from what I hear, all the pros are using it and it may be a cheap option to use as a purging/flushing agent. Greenfreeze that I mentioned above is a derivative of it and smells the same and I use that in my systems as it's environmentally friendly as well as being compatable with all the other gasses, not only that, it gets colder.
As regards potential leaks; may just pay to run a spanner over any fittings you can get easy access to as a precaution, as "O" rings have a hanit of settling and then weaping slightly. From what I've seen of late, this particularly applies to the two fittings at the firewall.
Alan S
With this mad weather we've got over here, I'm still running my air/con (winter officially starts in just over a week) as we are still getting above 30 degree days, but the morning temps are sometimes down a bit, into the teens, so as a result we aren't getting the high humidity and as a result, mine also feel a bit warmer than normal to me, yet I have passengers complaining about how cold they are.
We used to work on a temp at the vent of between 38 & 42, so in todays lingo, that's 3.33 to 5.55 C. so you are at the upper end of the scale.
It seems that the actual specs for these car air/con compressors is usually shrouded in mystery, so whilst they don't give an actual capacity, it is fair to guess that their capacity is in some ways connected to their designed running speed as with some marine applications I've been involved with, however, it should be in the ball park given the lesser load it would have to contend with over there, it's just that it would possibly be moe efficient with the other one particularly if you are running a condensor off an 8 valve system.
With the knowledge that the system was open for a prolonged period, you may have a good point with the possibility that the receiver dryer may have gone past its use by date as I have heard of some of these BX systems that have been contaminated being clagged up inside with a black gooey stuff that takes some shifting, so a really long pump out with a vacuum pump couples with a couple of flushes and possibly a new filter dryer might be a good move.
Latest trick out here to flush them out is they use LPG. Yep, same stuff that you use in the barbeque.
It was used as a refrigerant donkeys years ago and is apparently compatable with all the oils, O rings, seals and gasses and costs peanuts. Was dropped many years ago due to its volatility so don't light up while it's being used, but from what I hear, all the pros are using it and it may be a cheap option to use as a purging/flushing agent. Greenfreeze that I mentioned above is a derivative of it and smells the same and I use that in my systems as it's environmentally friendly as well as being compatable with all the other gasses, not only that, it gets colder.As regards potential leaks; may just pay to run a spanner over any fittings you can get easy access to as a precaution, as "O" rings have a hanit of settling and then weaping slightly. From what I've seen of late, this particularly applies to the two fittings at the firewall.
Alan S
By the time you're old enough to know it all, you can't remember why you were learning.
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mat_fenwick
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Well, I managed to borrow a probe from work and the vent temperature was 4.9 degrees C minimum - mind you ambient was about 15 degrees so will try again when (if?) the weather warms up.
Good point about a vac out - the company I was going to used for a re-charge (but moved house before the system was finished) suggested leaving it pumping down overnight wheras the company I did used said that wouldn't be required and that 15 minutes would do
Thanks for the info.
Good point about a vac out - the company I was going to used for a re-charge (but moved house before the system was finished) suggested leaving it pumping down overnight wheras the company I did used said that wouldn't be required and that 15 minutes would do
Thanks for the info.
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AlanS
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15 minutes is OK just for a regas on a dry system that has slowly lost its charge, but for one that has been open for any period, a flush out, fresh receiver dryer and pumped out at least overnight is a must.
An accumulation of moisture that would fit on the head of a pin will stop a unit dead in its tracks and you may find that what is happening is that refrigerant flow through the receiver dryer has been inpeded by an accumulation of contaminents. This can give the same basic symptoms as being short of gas.
When testing, it should be done with the temp control set at maximum, window open and engine running @ 1500 rpm min.
If the ambient was down, it may have an effect although, if it still holds that temp at say around a 25 ambient, I'd be happy with that.
Incidentally, had our first "cold" morning yesterday; 10 degrees!! How silly is that for it being a week short of the official start of winter? It was showing 34 on the Xantias thermometer a couple of days ago. No wonder everybody's feeling washed out. 
Alan S
An accumulation of moisture that would fit on the head of a pin will stop a unit dead in its tracks and you may find that what is happening is that refrigerant flow through the receiver dryer has been inpeded by an accumulation of contaminents. This can give the same basic symptoms as being short of gas.
When testing, it should be done with the temp control set at maximum, window open and engine running @ 1500 rpm min.
If the ambient was down, it may have an effect although, if it still holds that temp at say around a 25 ambient, I'd be happy with that.
Incidentally, had our first "cold" morning yesterday; 10 degrees!! How silly is that for it being a week short of the official start of winter?
It was showing 34 on the Xantias thermometer a couple of days ago. No wonder everybody's feeling washed out. Alan S
By the time you're old enough to know it all, you can't remember why you were learning.