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New R410a gas condenser units
February 22, 2011
7:54 am
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Steve Pooler
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If I'm understanding your translation of 640 watts " measured with sea-water temp of 82.4 °F, a fresh water inlet of 53.6°F, and outlet 44.6°F" (the rest of it I understood very little)

That to me would be RLA (run load amps) after the loop has reached operating temp…Not FLA (full load amps)… Dometic rates as FLA which will be higher than RLA…

I did go back & look at their parts section to check what kind of components the units have…It was interesting to me that they utilize the same type plate coil (or looks to be) for the seawater coil, as Dometic uses for the fresh water coil…

Yes…The advantage to that type coil is that it has much more surface area when compared to a tube in tube design which does make it very efficient…but…

To me the disadvantage to that type of coil for seawater use is that it has many very small passages that the water travels thru, and it could get fouled with marine growth very quickly or easily…Also the wall thickness of the metal that separates the refrigerant from the water is usually very thin in those type coils….I'm just not so sure how the combo of those two factors would affect the operational maintenance schedule, and longevity of that coil when used in seawater.

 

Steve~

February 21, 2011
10:26 pm
Francois
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February 20, 2011
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Dear Steve, thanks for reply.

 Here is the reply from Frigomar technical dept about their ratings of their chiller Micro 18 (220V): I tried to translate it for you.

"Le rendement de 18.000 BTU/h est le maximum que nous avons obtenu au Labo
avec une température de condensation gaz d'environs 30°C et une température
d'évaporation gaz d'environs 5°C. "= the efficiency capacity of 18.000 BTU/h is the maximum they had in their lab with a condensation temp of 86°F and an evaporation temp=41°F

"La consommation électrique 640 W a été mesurée avec une température d'eau de
mer 28°C et température d'entrée eau douce 12°C et sortie 7°C. "= the electric consumption of 640 W was measured with  sea-water temp of 82.4 °F and a fresh water inlet of 53.6°F and outlet 44.6°F.

"Dans nos machines les échangeurs sont surdimensionnés (en terme de surface d'échange)
et donc l'efficacité énergétique est très élevé, par exemple en
fonctionnement été avec température d'eau de mer de 28°C nous avons une
température de condensation d'environs 35°C. "= in our units the coil exchangers are oversized (higher thermic exchange area) so the efficiency is very high, for example with a sea water temp of 82.4°F they have a condensation temp of 95 °F.

Does it help you ? So at the end what do you think about their chiller units ?

February 21, 2011
9:13 am
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Steve Pooler
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I just Googled Frigomar and was able to come up with this page for ratings...** you don't have permission to see this link **

Frigomar is being honest by giving the Kw rating at differing inlet water temps.

According to their chart at 28 C (82.5 F) the unit does only draw 640 watts (.64 Kw)

But I don't see if that rating is FLA or RLA (full load or run load)

 

Steve~

February 21, 2011
8:27 am
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Steve Pooler
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François~

The above link is not good from here…I've tried it several times but…

I believe we are talking about 220 volt 50Hz correct ?…If so that works out to only 2.9 amps…Yes Very efficient….

Dometic does not make a 18K unit (only 16K & 20K) with the 16K drawing 4.3 amps, and the 20K is 6.3 amps at that voltage/cycles…

However, the power rating game can be a bit decieving…Are they rating it at Full Load, or Running load ???

Dometic's ratings are at Full Load when the loop water is at it's warmest…They will draw much less when running in the operating range after the pull down…

Seawater temp also has a big affect on this…Dometic uses I think 85 degree F water for the rating…Frigomar may be using 70 degree or lower depending on their reginonal water temps…The higher the water temps…The higher the amp draw will be..

Add to that if the system condenser coil gets dirty, or has reduced water flow, but obviously they will rate at "as new" condition with rated water flow.

I believe that they are using the same type/design compressors, as well as condenser coils, so I would expect the amperage draw to be very similar when run side by side in the same conditions… 

 

Steve~

February 20, 2011
6:57 pm
Francois
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Hi Steve,
I have found a great chillers on Frigomar website:

** you don't have permission to see this link **

How can you explain their units are so efficient EER=27 !! (640w for 18000 BTU ) ???
Compared to your units.
regards,
François