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Old 07-27-2019, 12:18 AM   #1
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Default Nova Kool R3800 AC/DC Refrigerator

Anyone have any good or bad experiences with this?

I'm thinking of switching out my Dometic 8501 -3 way to this AC/DC unit.

I have a 160 watt Zamp Solar panel that generates 9 amps per hour and probably about 72 amps per day with full sun plus I have two AGM batteries with a 224 amp hour storage ....

The replacement compressor fridge draws a maximum of 2.2 amps per hour and even if it ran 24 hours it would only be 52.8 amps total.

Anyone see any problem with that scenario?

I'm tired of having elevation problems with the gas units and even they use electric power especially over 5,000 feet.
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Old 07-27-2019, 12:42 AM   #2
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Originally Posted by Roadtrek Adventuous RS1 View Post
Anyone have any good or bad experiences with this?

I'm thinking of switching out my Dometic 8501 -3 way to this AC/DC unit.

I have a 160 watt Zamp Solar panel that generates 9 amps per hour and probably about 72 amps per day with full sun plus I have two AGM batteries with a 224 amp hour storage ....

The replacement compressor fridge draws a maximum of 2.2 amps per hour and even if it ran 24 hours it would only be 52.8 amps total.

Anyone see any problem with that scenario?

I'm tired of having elevation problems with the gas units and even they use electric power especially over 5,000 feet.

We assume you are using "amps" for "amp hours" and "amps per hour or day" to mean "amp hours per hour or day", but you do mean "amp hours" for the batteries as total capacity not per day or hour. Also mean that 2.2 amps per hour on the frig is amp hours per hour and not 2.2 amps for an hour which can be totally different depending on duty cycle, as that frig may use more than 2.2 amps when running unless they have the compressor speed very low.



I very, very, seriously doubt that you would get 72 amp hours per day out of 160 watts of solar. I would guess closer to 45-50 under good sun and could be as low as 5 amp hours per day if raining and/shaded.



Most compressor frigs of that size will use between 25 and 50 amp hours per day and be quite dependent on conditions for power use. Of course this also means having a good installation that vents well, which from what we have seen is often not the case even for factory mounted compressor frigs.



As with everything RV, a lot will depend on your use patterns. How much power do you use now? How often do you drive long enough to charge the batteries? Do you park in the shade if possible? How many days do you need to be able to sit without driving?


224 amp hours of batteries is enough for many people to have a compressor frig, but can also be not enough for many people, so there is not a hard and fast answer to that question. "It all depends."
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Old 07-27-2019, 01:08 AM   #3
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Default This Nova Kool R3800 uses only 2.2 amps per hour when it's running....pretty low ..

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We assume you are using "amps" for "amp hours" and "amps per hour or day" to mean "amp hours per hour or day", but you do mean "amp hours" for the batteries as total capacity not per day or hour. Also mean that 2.2 amps per hour on the frig is amp hours per hour and not 2.2 amps for an hour which can be totally different depending on duty cycle, as that frig may use more than 2.2 amps when running unless they have the compressor speed very low.

I very, very, seriously doubt that you would get 72 amp hours per day out of 160 watts of solar. I would guess closer to 45-50 under good sun and could be as low as 5 amp hours per day if raining and/shaded.


Most compressor frigs of that size will use between 25 and 50 amp hours per day and be quite dependent on conditions for power use. Of course this also means having a good installation that vents well, which from what we have seen is often not the case even for factory mounted compressor frigs.

As with everything RV, a lot will depend on your use patterns. How much power do you use now? How often do you drive long enough to charge the batteries? Do you park in the shade if possible? How many days do you need to be able to sit without driving?


224 amp hours of batteries is enough for many people to have a compressor frig, but can also be not enough for many people, so there is not a hard and fast answer to that question. "It all depends."
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Actually, I've looked into the a lot of different RV compressor units and found this so far to be the lowest consumption rate.

I called and talked with Zamp Solar and they gave me the 9 amps per hour....72 is based on 7 hours of sunlight....of course it would be less on cloudy days....

You're right...could be 5 amps if its raining.....I also have a generator.

Don't usually camp in the rain....try to avoid it....cabin fever��.

Also from a safety issue, not having the propane burner going while driving or pulling into a service station is much safer...

From what I understand the unit will "cycle on and off"; it will not run 24/7

Even if it did the maximum amps would be 52.8 … 24 hours times 2.2 per hour.

Big question is my other systems like lights, pump for water, toilet, etc.

My problem is SPACE.... My current cut out for the 8501 appears to be too small for a Norcold 3104...

There's a few other Norcold units like the N306x , it's a 3 way, but, it won't switch automatically... has a funky design that you have to start the gas with a push button.

Then, there's the elevation problem.... even over 5,000 feet, you still have to be on electric, propane gas fails above that altitude.

See the attached spec sheet.
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File Type: jpg Nova Kool 2.2 amps per hour.jpg (184.9 KB, 29 views)
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Old 07-27-2019, 01:46 AM   #4
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-------------------------------------------------------------------------------

Actually, I've looked into the a lot of different RV compressor units and found this so far to be the lowest consumption rate.

I called and talked with Zamp Solar and they gave me the 9 amps per hour....72 is based on 7 hours of sunlight....of course it would be less on cloudy days....

You're right...could be 5 amps if its raining.....I also have a generator.

Don't usually camp in the rain....try to avoid it....cabin fever��.

Also from a safety issue, not having the propane burner going while driving or pulling into a service station is much safer...

From what I understand the unit will "cycle on and off"; it will not run 24/7

Even if it did the maximum amps would be 52.8 … 24 hours times 2.2 per hour.

Big question is my other systems like lights, pump for water, toilet, etc.

My problem is SPACE.... My current cut out for the 8501 appears to be too small for a Norcold 3104...

There's a few other Norcold units like the N306x , it's a 3 way, but, it won't switch automatically... has a funky design that you have to start the gas with a push button.

Then, there's the elevation problem.... even over 5,000 feet, you still have to be on electric, propane gas fails above that altitude.

See the attached spec sheet.

Again you are using amps for both amps and amp hours which mucks all this up to try to figure out.



The Nova Kool spec is given as 2.2 amps which means when the compressor is running it will use 2.2 amps. This is not the efficiency or lowest power comparison number you want to use as it is not a power rating as in amp hours. If the duty cycle is 100% it will use 52.8ah per day under the same conditions as rated. It it very hot out it could easily use more because the compressor will use more the 2.2 amps when running. The 25 to 50 amp hours per day is a power number in the same units as your battery power capacity and is the kind of number you need to use to compare units as running amps means not much at all in most cases.


Did Zamp tell you that the 160 watt panels would give you 9 amps of current (that would be under perfect sun) maximum, or did they tell you would get 72 amp hours per day? Again amps and amp hours are not the same thing. Your panels will not make 9 amps for 8 hours a day. The normal number used for solar, unless they are the new super efficient ones is 30 amp hours per day per 100 watts of panel in good sun in the summer. That would give you 48 amp hours a day of power, not 72 amp hours and is a reasonable number that is similar to what many of us get on average. Less than good sun and it gets worse.


You need to start comparing units using appropriate units for power, either per hour, but preferably per day. You have such mixed up information you have no real clue how you would turn out for battery use.

Of course, you are free to do what ever you want and probably already have decided.
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Old 07-27-2019, 02:13 AM   #5
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Not sure what model it is, but we have a NovaKool compressor fridge, factory installed in our Paseo. It has separate fridge/freezer, and is a pretty decent size for a class b fridge.

I'm guessing on a really hot day if you leave the van closed up, it will run pretty close to 100% duty cycle. But if you open windows and leave a roof fan running, more like 30-50%. We have 200W solar, and have found that in sunny weather, temps in the mid-70's to low-80's, the solar can keep up pretty well indefinitely. Rainy or cloudy days, and at bedtime you won't be sitting at a full charge, and after about 2 days you will need to either run the van or the generator to get back up to full charge.

Winter is a totally different story, even if it is sunny. The solar just can't keep up with the combination of running the heater fan and running the fridge. Even in bright sunny Death Valley in February, we end up running the van about 30 minutes per day to keep the batteries charged.

I much prefer running the van to running the generator - it charges quicker and is much, much, much quieter.
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Old 07-27-2019, 03:16 AM   #6
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Default Clarification....

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Originally Posted by booster View Post
Again you are using amps for both amps and amp hours which mucks all this up to try to figure out.



The Nova Kool spec is given as 2.2 amps which means when the compressor is running it will use 2.2 amps. This is not the efficiency or lowest power comparison number you want to use as it is not a power rating as in amp hours. If the duty cycle is 100% it will use 52.8ah per day under the same conditions as rated. It it very hot out it could easily use more because the compressor will use more the 2.2 amps when running. The 25 to 50 amp hours per day is a power number in the same units as your battery power capacity and is the kind of number you need to use to compare units as running amps means not much at all in most cases.


Did Zamp tell you that the 160 watt panels would give you 9 amps of current (that would be under perfect sun) maximum, or did they tell you would get 72 amp hours per day? Again amps and amp hours are not the same thing. Your panels will not make 9 amps for 8 hours a day. The normal number used for solar, unless they are the new super efficient ones is 30 amp hours per day per 100 watts of panel in good sun in the summer. That would give you 48 amp hours a day of power, not 72 amp hours and is a reasonable number that is similar to what many of us get on average. Less than good sun and it gets worse.


You need to start comparing units using appropriate units for power, either per hour, but preferably per day. You have such mixed up information you have no real clue how you would turn out for battery use.

Of course, you are free to do what ever you want and probably already have decided.
Zamp said that the solar panels system would generate up to 9 amps per hour in full sun... yeah, I understand it's less if it's less sun or later in the afternoon... My panels are 2 years old... pretty new... and efficient ..Zamp solar system.

I'm huddling with my RV shop on this and haven't made any final decisions.... you're making a lot of assumptions about what I'm doing.....

I'm talking about this with different suppliers and manufacturers to determine the best solution.... I appreciate your input, but, you don't have to lecture me and say I don't have any idea .... I don't appreciate or agree with your characterization...

Nova Kool said that the maximum amount of power is 2.2 amps per hour... period... and it would never exceed 52.8 amps per day in any 24 hour period no matter how hot it is... No offense, but, I'm sure that they know more than you do about their product.

I also considered a larger solar panel array, but, the folks at Zamp pointed out that 1. I don't need it and 2. A larger size panel system would just charge my batteries faster...

Unless I got additional batteries, there's no place to store that extra power.... I don't have any room for additional batteries.

If I could get the Norcold 3104 three way unit.... I might consider doing that....I'm fed up with Dometic....had it about two years and it's not impressing me....so so performance....

Seems like the complex propane gas units are too problematic with altitude, still require electric and are prone to failure and fires.
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Old 07-27-2019, 04:06 AM   #7
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"Never exceed 52 amps per day"

If you are gonna argue with Booster you need to use the correct units.

That should read "52 amp hours per day"

He is trying to tell you something and you are not getting it.
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Old 07-27-2019, 04:13 AM   #8
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I have the Novacool 3100 (3 cf) model and it runs very efficiently. Probably because temps are cooler at night and we don't open the door, but while the danfoss compressor seems to run a lot, we've never had to worry about our two 75 amp wet cell batteries getting us through a 15 hr. overnight boondock while also using a small dc powered television/dvd player, some lights, and even suburban 16k btu furnace.

Was it adequately ventilated by Airstream and have we tried it in 90+ degree heat? No, because we choose not to travel then.
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Old 07-27-2019, 04:18 AM   #9
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Default It's the R3800.... A 3.5 cubic foot model

Quote:
Originally Posted by BillsPaseo View Post
Not sure what model it is, but we have a NovaKool compressor fridge, factory installed in our Paseo. It has separate fridge/freezer, and is a pretty decent size for a class b fridge.

I'm guessing on a really hot day if you leave the van closed up, it will run pretty close to 100% duty cycle. But if you open windows and leave a roof fan running, more like 30-50%. We have 200W solar, and have found that in sunny weather, temps in the mid-70's to low-80's, the solar can keep up pretty well indefinitely. Rainy or cloudy days, and at bedtime you won't be sitting at a full charge, and after about 2 days you will need to either run the van or the generator to get back up to full charge.

Winter is a totally different story, even if it is sunny. The solar just can't keep up with the combination of running the heater fan and running the fridge. Even in bright sunny Death Valley in February, we end up running the van about 30 minutes per day to keep the batteries charged.

I much prefer running the van to running the generator - it charges quicker and is much, much, much quieter.
My Zamp Solar system is 160 watts, just a little smaller than your system.....

What size Nova Kool is in your RV? And what kind of batteries are you using, what solar panels system. ??

You said that it's a pretty "decent sized" model.. I'll bet it is larger than the one I'm looking at and draws more than 2.2 amps per hour.????
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Old 07-27-2019, 04:22 AM   #10
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Default Yes.. I meant 52.8 Amp hours per day....

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"Never exceed 52 amps per day"

If you are gonna argue with Booster you need to use the correct units.

That should read "52 amp hours per day"

He is trying to tell you something and you are not getting it.
Read between the lines... I kept saying it's 2.2 amps per hour in a 24 hours period.....

There's no confusion about that... I even included a spec sheet.

WOW..... amazing..... Again... you think you guys know more than the manufacturer ???? I don't think so.
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