Can you adjust chilled water temp on a Condaria aircon unit?

[Deleted User YDKXO]

Ok, just measured ours & it's 30cu m. Like you we are also a greenhouse. On the basis I would not have less than my 24k in the saloon I reckon yours is well underspeced. Not what you want to hear I guess...

There were 2 aircon options with my boat, a 48000Btu 'Med spec' system and a 64000Btu 'tropical spec' system and my boat has the Med spec system. Frankly as Vas and others have pointed out, were it not for the fact that I am a cold blooded Brit for whom any temp above 20deg is a heatwave, I probably wouldnt be complaining about it

 

[Forty_Two]

There were 2 aircon options with my boat, a 48000Btu 'Med spec' system and a 64000Btu 'tropical spec' system and my boat has the Med spec system. Frankly as Vas and others have pointed out, were it not for the fact that I am a cold blooded Brit for whom any temp above 20deg is a heatwave, I probably wouldnt be complaining about it

 

[jrudge]

Fundamentally there are 2 different systems, a compressor system which chills the water and a chilled water distribution/air handler system and the 2 systems effectively operate independently. The compressor system is set up to provide chilled water at 10deg. The distribution/handler system takes that chilled water at 10deg and attempts to cool the cabin spaces to the desired temps and with my saloon, it fails. What it comes down to on my boat is that the compressor system cannot provide enough volume of chilled water at 10deg to allow the air handlers to operate to their full capacity and thats just a function of the Btu output of the compressor system

Thanks to Edd at MBS who really is the most helpful guy despite having recently a knee replacement op, I have been going through various checks of the compressor and handler system and I am almost 100% convinced that the system is working to its optimum. There only remains one issue and that is to check the air temp from each of the handler air outputs in the saloon but I cant do that until I get a thermometer. There may be an issue with the way the handler units feeding the saloon are balanced but I wont know that until I can measure the individual air temps each produces

As for reducing the chilled water temp, Edd is adamant that my particular Condaria compressor system is designed to operate in the 10-12.5deg range and should not be adjusted downwards

If the compressors are running continually then I agree - but in post 13 you said they were cutting out as they got to 11 and 10 degrees. The issue to me would be that if the air handlers were still cooling the return temp would have risen and the compressors would not have shut down.

If they shut off then by default they are not running at capacity - they think they have done their job so they shut off - but that is not the case as the air handlers in the saloon should (a) be calling for cold water and (b) returning water with a temp rise on it as they draw in warm air and exchange it for cold.

As you don't have a thermometer - have you confirmed the temp of the water? Sensors in these things are notorious for failing ( mine at the beginning of the season had the "temp to low " sensor fail making the unit believe the water would freeze and turning off one compressor) Could it be the water temp sensor(s) are misleading the system hence the compressors are shutting down prematurely?

Finally - you have had the boat a while - did this happen last year?

 

[Forty_Two]

Get yourself an int/ext type of thermometer with a dual display they are cheap.

Drop the ext sensor into the outlet grille & hang the thermometer directly in front of the inlet grille.

What you are interested in is the temperature drop across the cooling coil. Your manual should give you the spec. This way absolute temperature doesn't matter just the drop across the air handler.

Edit: I get around 9 - 10C drop on each unit. My chiller goes down to 6.5C.

 

[Deleted User YDKXO]

If the compressors are running continually then I agree - but in post 13 you said they were cutting out as they got to 11 and 10 degrees. The issue to me would be that if the air handlers were still cooling the return temp would have risen and the compressors would not have shut down.

If they shut off then by default they are not running at capacity - they think they have done their job so they shut off - but that is not the case as the air handlers in the saloon should (a) be calling for cold water and (b) returning water with a temp rise on it as they draw in warm air and exchange it for cold.

As you don't have a thermometer - have you confirmed the temp of the water? Sensors in these things are notorious for failing ( mine at the beginning of the season had the "temp to low " sensor fail making the unit believe the water would freeze and turning off one compressor) Could it be the water temp sensor(s) are misleading the system hence the compressors are shutting down prematurely?

Finally - you have had the boat a while - did this happen last year?

J its always been an issue with this boat but to be fair I've never been entirely satisfied with the performance of the aircon system on any boat I've had in the Med, at least so far as the saloon is concerned. I suppose I'm thinking that if I can drive my car around at 21deg inside without putting covers over the windows or cool my office to 21deg on even the hottest day, why can't I do that with my boat

The compressors shut down at 10deg. Thats a fact according to the spec of the unit and I can't alter that. As I said the issue is not that they shut down at 10deg but that they do not produce enough volume of chilled water at 10deg for the air handlers to cool down the saloon to the temp I want. In the sleeping cabins, the system works fine and easily cools the cabins to the desired temp.

 

[Deleted User YDKXO]

Get yourself an int/ext type of thermometer with a dual display they are cheap.

Drop the ext sensor into the outlet grille & hang the thermometer directly in front of the inlet grille.

What you are interested in is the temperature drop across the cooling coil. Your manual should give you the spec. This way absolute temperature doesn't matter just the drop across the air handler.

Edit: I get around 9 - 10C drop on each unit. My chiller goes down to 6.5C.

Thanks good advice

 

[MapisM]

The compressors shut down at 10deg. Thats a fact according to the spec of the unit and I can't alter that. As I said the issue is not that they shut down at 10deg but that they do not produce enough volume of chilled water at 10deg for the air handlers to cool down the saloon to the temp I want. In the sleeping cabins, the system works fine and easily cools the cabins to the desired temp.

M, I'm not convinced that you've got a problem with the chilled water volume, and I tend to agree with jrudge that there's something that doesn't stack up in the behaviour of your system.
You said that you tried shutting down the cabins and run the a/c in the saloon alone, and even if the circulating water is still flowing also inside the cabins air handlers, in that situation it's not much warmed/affected by them anymore. This is akin to giving to the saloon air handlers all the cooled water that the chiller can produce, i.e. more BTUs than the saloon air handlers alone can handle.

In those conditions, if you have:
1) chiller operating and cycling normally, and
2) only saloon air handlers running (at their max fan speed),
BUT you still can't reach the desired temp in the saloon, then imho the problem ain't the chiller capacity, but rather something more related to the saloon air handlers - be it their capacity, obstructions, position, internal air flow, whatever.

Anyway, you might be interested in the sort of opposite test that I just made after checking the manual, since my system is exactly the same as yours, bar the lower capacity.
As I previously mentioned, the cooling set point in my system was set to 8deg, rather than 10 as specified in the manual.
And even if I can't be positive about this, I believe it spent its whole 14 years life running with that setting, with no problems whatsoever.
But since it always did its job nicely, even in a few occasions when I used only one compressor due to dockside AC limited to 16A, I thought to raise the cooling set point to 10deg, as per Condaria manual. And as I half expected, there was no perceivable difference.
I mean, theoretically the chiller should work a bit less, and it should take a bit longer to cool down the interior upon startup.
And maybe that does happen, but if someone would have changed the setting without telling me, I would have never noticed any meaningful difference.
Bottom line, I'm going to leave the setting as per manual, just for the sake of being consistent with it.

Otoh, if your system is struggling to cool down the saloon alone, in your boots I would definitely try to lower the cooling set point by a couple of degrees.
In fact, it is reasonable to expect that the chiller, which has no problem to reach and maintain 10C cycling regularly, would also be man enough to cool the water further, even if (possibly) running a bit more/cycling a bit less.
This way, AOTBE the air handlers would blow colder air, at any given speed - and in turn, this is bound to reduce also the internal temperature.
I understand your concern about changing the setting suggested in the manual, but aside from the fact that if a lower set point could damage anything by now my system would be shot, I can't figure any logical reason why it should.

Of course, if the change doesn't bring any meaningful contribution to the party, I would put it back at its original setting.
But while in my boat I found that there was no "need" for the 8deg setting (mind, I never tried cooling down to 21deg, as S would kill me! ), maybe in the case of your saloon, with seems more borderline, maybe those 2 degrees can be relevant...

 

[baylabayla3288]

If I got it right your compressor cuts out at 10C before you reach the desired temp in your saloon even when full fan speeds are in use? This tells me, as others have commented as well, that the bottleneck are the air handlers some how and not the chiller compressors.

To get more cooling you need to either circulate more air (higher fan speed/more air handlers) or get the water temp down. Are you using the fans in auto speed mode? The system is designed so that only full fan speeds loads the compressors fully but indeed, this is noisy. At least in my case when I adjusted the water temp down to min 7C from 10C the system appears more powerful. I got faster cool down and also the fan speeds stay mostly at level 1 for maintaining the temps. Also one need to keep all hatches and windows closed as any opening, even small, takes away the cool air very quickly.

As I’m also of the more cold blooded type wanting closer to 22 C rather than 25 C, this helped a lot. Also the max rated BTU cooling effect is at higher ambient temps so the effect available for cooler temps is less. Anyhow I have had the cutout water temp set to 7C for 2 seasons now without any negative effect what so ever, despite that the manual recommends not to do this. The temps are easy to adjust from the remote panel of the Condaria unit so in your place I would give it a try. I have not heard what the negative effect could be more precisely but I would expect that maybe one could get shorter compressor life, as more running hours could be a consequence.

 

[Deleted User YDKXO]

Guys thank you so much for your thoughtful comments. Just to summarise where I am now

1) I have physically checked all the air handlers in the boat myself. The dust filters are clean, I have bled the chilled water system at every handler and there was no air in the circuit anywhere. I have also set the chilled water circuit pressure to max allowable. During last winter I had the air ducting checked and cleaned in the saloon. The volume of air being pushed out by the handlers seems to be about what it should be for each fan speed although obviously I have no way of measuring that volume. I remain to be convinced that there is any issue with the air handlers

2) The compressor system is set to the manufacturers recommendation of 10-12.5 deg. I have been told unequivocally by Edd of MBS, the UK Condaria agent, that the chilled water temp set point should not be lower than this and in any case I wouldnt know how to lower it because the user manual does not give this information. So if I am to lower this set point, I need some advice from you guys how to do it!

3) My next course of action is to buy a decent thermometer in order to measure the temp of air being produced by each air handler. If there are any differences then of course I will focus on those

 

[MapisM]

if I am to lower this set point, I need some advice from you guys how to do it!

The procedure in the page "Programming" of the manual, as per previous post #24 from Markc, worked just fine in my system.
There's just one thing which is not specified: when you change the set point by pressing C1, the temp goes either down or up (I already forgot!) by 0.5 degrees upon each press of the button, but don't try any other buttons to go the other way round.
You just keep pressing C1, and the cooling set point cycles (within a limited range) till you leave it in the desired position, and press OFF button to end the process.

Btw, this also makes me think that you can't damage anything, since you can only set a value which is within a factory-defined range.
That said, I'm not going to buy you a new boat if she would blow up!

 

[Deleted User YDKXO]

The procedure in the page "Programming" of the manual, as per previous post #24 from Markc, worked just fine in my system.
There's just one thing which is not specified: when you change the set point by pressing C1, the temp goes either down or up (I already forgot!) by 0.5 degrees upon each press of the button, but don't try any other buttons to go the other way round.
You just keep pressing C1, and the cooling set point cycles (within a limited range) till you leave it in the desired position, and press OFF button to end the process.

Btw, this also makes me think that you can't damage anything, since you can only set a value which is within a factory-defined range.
That said, I'm not going to buy you a new boat if she would blow up!

Thanks missed that and thanks again to markc. I have now adjusted the set point down to 8.0deg and happily the upper point has also gone down automatically too. Adjusting it using the C1 button is a bit scary because as you say the set point temp initially goes up to 14.5deg but then it starts again at 6.5deg. So now I have a cycle range of 8deg to 11deg and my saloon is starting to feel a bit cooler but that might be wishful thinking. I will send the bill to you guys when my compressor unit blows up

 

[BartW]

...........and my saloon is starting to feel a bit cooler but that might be wishful thinking....

windfinder say's max 23°C in Antibes right now,
that would be nearly the moment that my wife would switch on the heating instead of the Airco

 

[baylabayla3288]

windfinder say's max 23°C in Antibes right now,
that would be nearly the moment that my wife would switch on the heating instead of the Airco

...you can adjust the max temp in a similar way for heating

 

[Deleted User YDKXO]

windfinder say's max 23°C in Antibes right now,
that would be nearly the moment that my wife would switch on the heating instead of the Airco

Maybe but it was 28.5 deg in my saloon today. Thats a heatwave in Britain!

 

[vas]

Maybe but it was 28.5 deg in my saloon today. Thats a heatwave in Britain!

and 27C now in my home office as I cannot be bothered to get up and find the aircon control to turn it on.
I think it's cooler outside but haven't moved from home yet today.

 

[MapisM]

I'm using this thread for another question related to Condaria chillers:
Does anyone know what should be the right pressure for the cooling liquid which is circulated around the fancoils?

There is a pressure gauge on my chiller, which I've always seen around 0.5 bar, but I can't find any references to what the ideal pressure should be.
Actually, the system does work well, and according to the manual a wrong pressure should put the chiller automatically in standby and trigger a red led alarm, so in a sense I'm concerned about a problem that doesn't exist.
But I think it's a bit weird to have (in my installation, anyway) a valve that allows to top up the circuit directly from the fresh water system, without knowing what the pressure should be - unless it is actually mentioned in a manual that I didn't find/read yet...
Btw, I'm aware that the circuit is supposed to be filled with fresh water+antifreeze, but I guess that the refill valve was fitted assuming that fresh water alone is ok for occasional small additions.

 

[markc]

My gauge has a MAX marker about 3/4 of the way around the dial, but I can't remember the scale! When I bought the boat the pressure was quite low and I used the valve you mentioned to top it up (I later found a small leak). IIRC the domestic water pump was not able to get the pressure to the MAX mark anyway, just to the 2 o'clock position.

 

[jrudge]

Mine I have a feeling is 1 bar but I am not really sure what difference it makes as if it goes down it still works fine

I guess it is pressurised so that when the water gets cold it does not get to the point of negative pressure and draws in air?

Same with the s58 steering system. It is pressurised with a bike pump but if it goes to zero it makes no difference !

 

[MapisM]

My gauge has a MAX marker about 3/4 of the way around the dial, but I can't remember the scale! When I bought the boat the pressure was quite low and I used the valve you mentioned to top it up (I later found a small leak). IIRC the domestic water pump was not able to get the pressure to the MAX mark anyway, just to the 2 o'clock position.

Well, if it's like mine, it goes from 0 to 2.5 bar, with thicker marks every 0.5 bar. I've got no "max" marker, though.
3/4 of the scale would be close to 2 bar in my gauge, which is just about the normal working pressure of fresh water pumps.

@jrudge: I'm intrigued by the concept of pumping air into a steering system!
Since I suppose it ain't fully pneumatic, is there an expansion tank to keep the oil circuit at the desired pressure?

 

[Deleted User YDKXO]

I'm using this thread for another question related to Condaria chillers:
Does anyone know what should be the right pressure for the cooling liquid which is circulated around the fancoils?

All I can say is that on my unit there is a pressure gauge marked in mH2O units with red marks at min 5 and max 20. In the past I have tried to keep the pressure midway between these points but Edd told me to keep the pressure close to max 20 which I have now done. Like you I am concerned about topping up the system with freshwater because that dilutes the antifreeze mix and presumably reduces the cooling performance of the system (or is the antifreeze added only to prevent freezing?)