Nova Kool R3800 AC/DC Refrigerator

[Roadtrek Adventuous RS1]

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.

[booster]

Originally Posted by Roadtrek Adventuous RS1

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."

[Roadtrek Adventuous RS1]

Originally Posted by booster

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."

-------------------------------------------------------------------------------

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.

[booster]

Originally Posted by Roadtrek Adventuous RS1

-------------------------------------------------------------------------------

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.

[BillsPaseo]

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.

[Roadtrek Adventuous RS1]

Originally Posted by booster

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.

[hbn7hj]

"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.

[rowiebowie]

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.

[Roadtrek Adventuous RS1]

Originally Posted by BillsPaseo

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.????

[Roadtrek Adventuous RS1]

Originally Posted by hbn7hj

"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.

[Roadtrek Adventuous RS1]

Originally Posted by rowiebowie

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.

SO..... your two 75 amp "wet cell" batteries get you through a 15 hours boondock with lights ..etc.....

I have two Centennial AGM 6-volt batteries CB6-224 rated at 224 Ah in series for a 12 volt system......

Your Nova Kool uses the same power consumption as the R3800....

If you can get by with the two 75 watts, then I would think that my system would easily handle this.

Actually, Nova Kool told me that they think I could manage to get by for longer than 30 hours..

I'm thinking worst case at least 10 hours no matter what...we don't normally camp in really hot weather....too uncomfortable....

But, I think the compressor refrigerator should be better able to work over the propane gas unit?? It doesn't have to be level or at an elevation lower than 5,500 feet.

[GallenH]

Roadtrek: I agree that this is a difficult one to calculate. We've discussed this before. LP fridges are iffy. Mine is 22+ years old. But I still can hold a 40- degree fridge at 9100ft. Maybe the older ones were better? I don't know. But my personal feeling is that I wouldn't convert unless I had 200 solar and 200Ah lithium. You mention you have 160 solar. Can you measure how much you're getting/hr/day out of that? Is it really that critical? You say you have a genny that you can use to replenish battery (I don't). It seems to me that when you convert you're in experimental mode. The other responders have gone through this and I think that booster's comment "depends" is really on target.

[SteveJ]

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

I guess someone forgot to tell my Domestic LP fridge that. I just spent over a month at elevations of 8000 to 9500 parked and drove higher than 11000 feet over some passes. Previous years were longer durations at these same elevations with this two year old fridge and a previous one new in 2000. Never had an issue at higher elevations.

So much for the experts.

[BillsPaseo]

Originally Posted by Roadtrek Adventuous RS1

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.????

I can't find a model number on it. And googling it, I'm finding conflicting information. It is either 5.5 or 6.0 cubic ft. It is 12V or 120V, auto switching.

And I have two solar panels, one 100W Zamp and one 100W Renogy. Both are monocrystalline. I have two 105AH AGM batteries, not sure the brand, I've never opened up the under body compartment to see what they are.

[Roadtrek Adventuous RS1]

Originally Posted by GallenH

Roadtrek: I agree that this is a difficult one to calculate. We've discussed this before. LP fridges are iffy. Mine is 22+ years old. But I still can hold a 40- degree fridge at 9100ft. Maybe the older ones were better? I don't know. But my personal feeling is that I wouldn't convert unless I had 200 solar and 200Ah lithium. You mention you have 160 solar. Can you measure how much you're getting/hr/day out of that? Is it really that critical? You say you have a genny that you can use to replenish battery (I don't). It seems to me that when you convert you're in experimental mode. The other responders have gone through this and I think that booster's comment "depends" is really on target.

I cannot say that for some of you were not.... I don't appreciate that...

Gallen, yes, I have the Zamp 160... interestingly, when I talked with them on the phone today... they said I don't need any more solar panels... unless I were to get additional batteries....I'm sure that they would have told me if I needed it... they're in the business of selling their product.... I appreciated their candor. You have to admit that's a breath of fresh air ....

And... while I don't have lithium batteries... I have two AGMs rated at 224 amps each in a 6 volt series for a total of 12 volts....

Yes, I have the propane generator... plus, I've found that charging up the batteries by just running the engine is pretty fast...

We use our RV mainly for touring... and driving long distances.

I'm thinking that the compressor fridge can run all the time even in fueling stations...

I guess you're very lucky to have a 22 years old propane refrigerator still working... mine is a 2011 Dometic 8501.... very disappointing performance....I don't have a lot of confidence in Dometic. I discovered in the owners manual that gas operation is limited to 3,280 feet with my model.... other Dometic units can operate up to 5,500 feet.
Every manufacturer told me that 5,500 feet was the limit on propane gas refrigerators.... after that, you're on electric anyway.

Plus, in 100 plus degree temps.. my Dometic can't barely keep it cool.... it's a big issue....I'm tired of running around looking for ice.

What model do you have?

[GeorgeRa]

[Amps per hour] is one of these hopeless units closely followed by battery capacity in [amps], incurable.

[hbn7hj]

Originally Posted by Roadtrek Adventuous RS1

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.

Booster does. He is running exactly what you are trying to build. Let us know how it goes.

It is not 2.2 amps per hour in a 24 hour period. It is 2.2 amps in a 24 hour period. Yeah, we can figure it out. It would be better if you said it correctly so we understand you can figure it out.

[booster]

Originally Posted by Roadtrek Adventuous RS1

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.

If you have a manufacture that is giving you terms like "amps per hour" or "amps of battery capacity" and at the same time giving you "amps" of solar output", you are not talking to anyone at the company that is knows what is going on as they don't know the difference between energy and power.

In that case, I would say that a whole bunch of people here and anyone who had a high school science class or took a 1 hour DC electronics class would know more than whoever you talked to at the manufacturers.

Why in the world do you think that you can get unbiased and accurate information from someone that is trying to sell you something but not from others who have tested data, training in the topic, years of experience, and most of all AREN'T TRYING TO SELL YOU SOMETHING, JUST HELP YOU MAKE GOOD CHOICES.

I certainly admit that some companies are putting out spec sheets that have wrong information of this type on them. I will also point out that they are almost always being written by marketing people or contractors who don't know much about the products or the tech. Remember that Roadtrek has used this unit substitution in their literature to deceive their customers, very possibly intentionally.

The Nova Kool should read one of two ways, as it does not tell us anything useful if it stated as amps per hour.

2.2 amps per hour is stated....which, by the way is not how it is stated in the spec sheet you posted, as it is plainly stated to be running amps and it is you that are changing the units.

If the unit is running at 2.2 amps while in use, that is a 2.2 amp rating.

If the unit is using 2.2 amp hours per hour of energy (battery capacity) that is a unit of power.

They are not the same and could give totally different amounts of battery life in use depending on the percent of time the frig runs.


You tell me which 2.2 amps per hour means, or even what the definition of that is.


Any frig manufacturer will be able to give you test results based on industry standards testing for energy use under specific controlled conditions. That is the information you need to look at, and it will probably even be in the right units so it would comparable and understandable.

Read between the lines...

When I do that, all I see in these posts is a bunch of blank space........

[booster]

I started another discussion to put in some information on evaluating specs and comparing various frig options in compressor versions. Included is why the running amps of any given frig, as a standalone spec, is not a good indicator of how much energy you are going to use. Some of the stuff is kind of counter intuitive, at least for me. No reason to fill this thread with the tech stuff as it will just get lost over time and be unfindable.


http://www.classbforum.com/forums/f5...pecs-9459.html

[Roadtrek Adventuous RS1]

[Moderator's Note: I have merged the new thread into the existing one. Please avoid creating redundant topics. Thanks.]

OK...on another thread.... someone has suggested that my two 224 Ah deep cycle AGM 6 volt batteries may not be enough reserve capacity to run a compressor refrigerator that has a maximum 2.2 amps per hour draw......

I also have a 160 Watt Zamp Solar Panel system producing 9 amps per hour...

I don't expect that the refrigerator will even run 24/7.... but, even if it did that would be a total of 52.8 amps per day in 24 hours.....

What do you think???

What am I missing here???