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

[MapisM]

So if the same air handlers are used what does that change?

Imho, not much.
If as I understood your existing compressors reaches its rated temp, I would try lowering the 10c to 8c first (my similar unit is already set at 8c and it always worked nicely).
If the cooling improves, good. But if not, I can't for the life of me see why replacing the chiller with a more powerful one should make a difference, unless you also fit some larger air handlers (if feasible).

Btw, Porto, did you actually understand what did Frigomar REALLY invent, that makes their unit draw less current for any given cooling power?
I mean, why on earth a compressor driven by a DC motor, feeded through AC+inverter, should be more efficient than a straight AC motor?
I understand the variable speed+continuous operation drawing less current once the desired temp is reached, as well as the lower spike, but whenever the system works at its max power, I'd expect the latter to be a bit MORE efficient than the first, if anything.
Unless their compressor side is more efficient for some reason, but that has nothing to see with the motor behind it, in principle.

 

[Mr Googler]

Trevor.....where are you when we need a proper expert

 

[Deleted User YDKXO]

Imho, not much.
If as I understood your existing compressors reaches its rated temp, I would try lowering the 10c to 8c first (my similar unit is already set at 8c and it always worked nicely).
If the cooling improves, good. But if not, I can't for the life of me see why replacing the chiller with a more powerful one should make a difference, unless you also fit some larger air handlers (if feasible).

I can't lower the chilled water temp setting. The 10-12.5 deg range is as recommended by Condaria and I dont want to operate the system outside its parameters. The air handlers are rated at max 6200 Btu/hr each and there are 10 on the boat (6 for the saloon and 1 for each of the cabins) so the total capacity of the air handlers is 62000 Btu/hr (sized I guess for the 64000 Btu tropical spec upgrade option chiller unit) so there is plenty of air handler capacity in hand for my 48000 Btu chiller unit. Today I checked the dust filters for all the handlers and they are clean and I have bled the chilled water circuit and there was no air in it. Also the water pressure according to the guage is within spec so that all tends to suggest that the chilled water circulation system and the air handlers are working fine

So the only option I have to increase the cooling performance is to increase the size of the chiller unit. Obviously I dont want to throw away a perfectly good 48000 Btu unit so the question is whether its possible to add a 2nd 16000 Btu chiller unit and if that is possible how would it work? Would both units be feeding chilled water into the existing circuit or would it be better to split the circuits such that the new 16000 Btu chiller feeds the cabin circuits and the existing 48000 Btu unit just feeds the saloon circuit?

 

[Portofino]

Time for a marine Aircon professional to come and have a look .
View attachment 72952

Actually pic taken in PV

Called Enzo .

 

[MapisM]

total capacity of the air handlers is 62000 Btu/hr (sized I guess for the 64000 Btu tropical spec upgrade option chiller unit) so there is plenty of air handler capacity in hand for my 48000 Btu chiller unit.

All well and good, if it weren't that (if I understood correctly) both your air handlers and your chiller are regularly cycling on and off, in spite of the fact that you can't get a temp as low as you wish, at least in the saloon.
I mean, assuming that your saloon air handlers are oversized vs. the chiller capacity, and the saloon thermostat never reaches your desired temperature, theoretically your saloon air handlers should never go off, and neither should the chiller unit, because it should be always working at its max capacity, without reaching the lower point (10deg) of its operating range.
Or am I missing something?

Anyway, ref. your last question, gut feeling tells me that it would be better to keep the second chiller running in parallel on the same circuit, but in your boots that's definitely something I would want to check with a good specialist, before forking out any money...

 

[jrudge]

I agree. If they are cycling they are not running at full capacity. Mine only cycle when all is chilled.

Mike. Is it you can’t reduce the temp or don’t want to ? The worse that can happen is no change surely.

 

[Portofino]

Sounds like the chiller units are too small .
For comparison we have a fraction of the vol could be less than a 1/4 .
18-42 K btu chiller and a 3 airhandlers 12+8+8 = 28 K in all .
Also circulation water temp of just 7 degrees .Theres no range here remember as it never shuts off ,being D.C. just slows down as required .

You conventionally cycling AC stuff be it from 10 to 12 degrees is inefficient as when off , it not cooling as much waiting for the rise to 12 to restart .

Can,t be as efficient cooling the handler s than a constant 7 running through , with variable fan speed linked to the room thermostats.

So using the same top figures for consistency that’s 42 K chiller for 28 K btu air-handlers compared to Mikes 48k chillers to 62 K air handlers

Hence a bigger chillers and colder will work for the saloon .
Mikes saloon has all the - ve variables- open door (s) , huge glazed areas , which seemingly are not shaded with external covers , blinds left open , helm glass facing the sky , carpet ,loads of furniture, lights ( poss LED ? )

I realise you are not considering a change because of the amps trip thingy , or relative silence or the comp .
But mine draw as little a 2 A when @ set temp because while constantly runing it’s are waaaay on top of the game .

Ideally a pair of Frigomar 62 ,s split saloon / down below gives 124 K max for 64 K airhandlers.This means there’s room to beef up the saloon airhandlers,so doors really can be left open ,blinds up , sunscreens left a locker :encouragement:

You will be able to leave a rose on the table and it will chill all by itself

 

[MapisM]

So using the same top figures for consistency that’s 42 K chiller for 28 K btu air-handlers compared to Mikes 48k chillers to 62 K air handlers

I don't think that's a correct reasoning.
My understanding is that the total cooling capacity is bound to be the smaller of the two numbers.
In your example, what you've got is a 28k BTU system, as opposed to 48k of Deleted User, period.
And the room for upgrades, if needed, is through an additional 14k BTU air handler(s) in your system (matching the total 42k capacity of the chiller), as opposed to an additional 14k BTU chiller(s) in Deleted User system, to fully exploit the total existing capacity of the air handlers.

The fact that Frigomar is designed to circulate water at 7 degrees as opposed to 10 or whatever of the Condaria is a red herring, imho.
Regardless of the technology behind it, the BTU capacity is just that, the system cooling capacity: of course different technologies mean that system A can be more efficient than B in terms of current needs, but the final result in terms of internal temperature is bound to be the same for any given A and B systems with the same BTU, regardless of current absorption, temp of cooling water, or any other technical differences.

Btw, you keep comparing AC with DC, but that's sort of misleading.
My understanding in that Frigomar systems are running on AC as much as any others.
It's just the compressor motor which runs on DC, through a dedicated inverter.
Which is the reason why I asked if you are aware of any other differences which I might be missing (see 2nd para of my post #41)...

 

[BartW]

Mike, have you tried switching off the air handlers in the cabins, so that you have all cooling capacity available in the saloon ?
if that works, you could adapt your modus operandi, so that in daytime, you use all power for the saloon,
and from lets say 22hr isch you sart the handlers in the cabins, (your own cabin a bit earlyer ;-) )

 

[Deleted User YDKXO]

Mike, have you tried switching off the air handlers in the cabins, so that you have all cooling capacity available in the saloon ?
if that works, you could adapt your modus operandi, so that in daytime, you use all power for the saloon,
and from lets say 22hr isch you sart the handlers in the cabins, (your own cabin a bit earlyer ;-) )

Yup we do that anyway. I always switch off the air handlers in the cabins which arent being used and vice versa at night switch off the saloon air handlers. Actually it doesnt seem to make much difference!

 

[MapisM]

Actually it doesnt seem to make much difference!

M, just a thought: I can't remember how the air handlers work in your boat, is their speed automatically controlled?
My air handlers can work at either two (the smaller ones) or three speeds, but the electrical system was built in such way that I can control their speed manually, and independently of the pre-set thermostatic temperature.
I suppose the rationale behind that was that you might wish to keep them running as silently as possible, even if at cost of a slower cooling.
Anyway, should your boat be configured as mine, you can only tell if the capacity is good enough by keeping the air handlers at their max speed, and let them cycle on/off as required.
I mean, surely the rated BTU capacity of each air handler is calculated at their max fan speed, not at the lower.
Otoh, if in your boat the air handler fan power is automatically regulated, forget what I just wrote!

PS: regardless of the above, also in my boat shutting down the cooling in one section of the boat doesn't improve the effectiveness of the system in the other. Actually, it's almost the opposite - in my experience so far, it can take a bit longer to cool down the whole boat interiors, but once reached the desired temp in the whole boat, I can keep all air handlers at the lower speed, the chiller seems to run effortlessly, and the whole environment is very comfy.
Then again, the volumes are much smaller than in your F630, let alone BA...

 

[Deleted User YDKXO]

M, just a thought: I can't remember how the air handlers work in your boat, is their speed automatically controlled?
My air handlers can work at either two (the smaller ones) or three speeds, but the electrical system was built in such way that I can control their speed manually, and independently of the pre-set thermostatic temperature.

Nope mine work like yours. You choose a speed depending on how much you enjoy conversing with your wife, because of course the higher the speed the more noisy they are, and the air handler only deviates from that speed when it reaches the desired temp. Of course if I want max cooling I have to set the fan speeds at max and sit in silence

 

[MapisM]

Of course if I want max cooling I have to set the fan speeds at max and sit in silence

LOL, that's what in EN you would call killing two birds with one stone, IIRC?

 

[Deleted User YDKXO]

LOL, that's what in EN you would call killing two birds with one stone, IIRC?

Yes even better max fan speed kills all conversation and allows me to surf the forums in relative peace and remain cool

 

[Forty_Two]

Do you have mesh sun covers on the saloon windows, they make a very useful difference. Ours are white.

We have 2 x 12k air handlers in the saloon, glass right round, the covers mean we often don't need to run the AC. (We do have plenty opening windows though). 6k in each of the two cabins & a 36k chiller (Marine Airrr).

Makes no sense that running without the cabins on doesn't improve the saloon cooling. Even though it's clear your chiller is underpowered for the Installed air handlers if you can't get the saloon right with everything else off then the saloon airhandlers are underpowered for the heat gains in the saloon.

Our 24k in the saloon works well but your saloon must be greater then 50% larger than our GB42 which which is all your installed 37.2k would cope with compared to us.

 

[jrudge]

Something must be wrong if the compressors are cycling before the main demand is satisfied ( ie the boat is cool )

The air handlers should be taking all the cold they can get and returning warmer water. This should keep the compressors running until the return water is at a low temp and allows them to shut off

Water flow to the air handlers restricted in some way? Tap part off? Other blockage ? Pump running too slowly hence circulating less water?

These systems typically run at 7. I know that the spec of his system is apparently different but personally I would turn it down ( from this thread I think it is adjustable but you are choosing not to ) just as something to try

 

[baylabayla3288]

There is when new and without it they deny warranties. Read the manual !I agree getting it in would be a pain

Now I read the manual and indeed it is filled with anti freeze mix from factory, I only need to check the the mix. There is a valve preventing the antifreeze to flow back into the fresh water system. This is good news and makes it easy as only the raw water need antifreeze for the winter. Thanks for the info!

 

[Deleted User YDKXO]

Do you have mesh sun covers on the saloon windows, they make a very useful difference. Ours are white.

Yes we have those. Our saloon is something like 100 cu.m in volume and with large windows so basically it is a greenhouse!

 

[Forty_Two]

Yes we have those. Our saloon is something like 100 cu.m in volume and with large windows so basically it is a greenhouse!

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...

 

[Deleted User YDKXO]

Something must be wrong if the compressors are cycling before the main demand is satisfied ( ie the boat is cool )

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