Questions about Nova kool fridge

[Butch50]

Wayne, would you please let this post stay in the TC section as they have the most knowledge of the DC compressor fridges.

X TCer here and I have some questions for the folks that have the DC compressor fridges. I'm tired of my Norcold fridge and its poor performance so looking to replace it with a DC compressor unit.

I have room for the Nova Kool RFU6800 6.8 cu ft unit. This would be replacing the Norcold N3160 5.3 cu ft unit Surprisingly the Nova Kool cutout size is a little smaller than the Norcold so I would have to do a little work to make the opening smaller. Do I need to retain as much venting area on the outside of the rig for the Nova Kool as I have for the absorption fridge?

So a question is there any reason to get the Nova Kool with the AC option which adds to the cost of the unit? As far as I can see the AC option is wasted as you still have to convert it back to 12 VDC to run the fridge because the Danfoss compressor is a 12VDC unit. When plugged into shore power why not let the built in converter in the RV provide the DC power to the frdge?

The Nova Kool 12VDC draw is 5.2 amps so I'm changing out my two 12 volt batteries for two 6V Trojans T145s. I can only get 2 batteries into my battery area but I have a lot of height so can fit in the T145s. I would be adding 300 watts of solar minimum before adding the fridge. Do you folks see any reason why this well not work. I'm not a power hog and all of our lights are already LEDs. What is you thoughts on the amount of solar I'm looking at do you think it is enough? When we are out in the woods the TV is never on. M wife has a CPAP but we have a lithium battery for it and it runs her CPAP for 2.5 nights before needing recharging. if we drive at all we plug it into the 12VDC power port to charge it off the vehicle. I'm thinking the 300 watt solar would provide enough power to recharge this battery also for the CPAP.

Thoughts?

Thanks in advance

Butch

[67avion]

Butch50 wrote:

Thanks for the reply, this is helpful knowing that 300watts solar should handle it. We don't stay in one place long so the engine would be adding to the charge also.

We originally had 3 AGM series 31 batteries until a mishap last year. In the ensuing repairs we didn't replace one of the batteries - leaving just 2. I thought I'd be in trouble with our Nova Kool installation. As it turned out we had no problems at all during a Florida trip this late winter. Now, we tend to move almost everyday on the road...so that might be part of the answer. And it was unseasonalby cool when we visited, so that might explain something.

But the 200 watt solar panels kept the batteries charged and our draw down during the evening was quickly replaced by late morning.

We do have an opening for exhausting any heat from the fridge, but it is very small and not noticeable either way.

[Butch50]

crosscheck,

Thanks for the reply, this is helpful knowing that 300watts solar should handle it. We don't stay in one place long so the engine would be adding to the charge also.

[Geewizard]

crosscheck, how did you cover the inside of your vents? I want to do the same to mine and for the same reason.

[crosscheck]

Sitting in Apache Juntion replying to the OP questions. Temps in the high 80's.
Our 7.5 cuft NovaKool still performing well in year 6 with 330w solar and 4 6v AGM batteries(400ah). We ordered the AC/DC option. Seldom plug in unless at home but who knows when you will use the AC option in the future or for resale.

Have been well out of level numerous times so a Danfos compressor is a must for our kind of camping. Venting: Our TC came with top and bottom fridge vents. When we left BC March 31st, it was cool so I left the plastic insulation covering the inside of the vents on so we can benefit from the small amount of heat produced by the unit. Now the temps have climbed considerably, When we arrived at Lost Dutchman, I removed it. Nice to have the option.

We carry our Honda genny along but never need it with our solar and 4 batts. 17 days camping so far and had to take an electrical site at Snow Canyon to get a site but other than that, batteries are topped up usually by noon at 14.42v (max charging level). 4 batteries would be ideal but if you are carefull, 2 of the largest ah models that you can fit in your rig will work. Put in as much solar as you you can or at least design system to add on.

Good luck

Dave

[Butch50]

Thank you everyone for all of your information and thoughts. This really helps a green horn on solar and DC compressor fridges.

I do have a couple of Dometic portable DC compressors fridges already and really like them. I bought them because of the problems with my Norcold. One I well still carry as it is a smaller one and well be used for drinks (have to keep the adult beverages cold, very cold). I know when I plugged my first one I bought I was really impressed with how quickly it cooled down. I could feel the difference in a matter of minutes. I have a CF 035 and a CF 025 and really like both of them. When I was experiencing the worst problems with our Norcold we used the 35 for a freezer and the 25 for a fridge. Worked out really well. I bought ice for the Norcold and placed the ice in zip lock bags and placed them into the Norcold to try and cool it back down.

Alex,

I viewed you excellent installation post of your DC fridge install when you posted it. I got a lot of information from your install.

[c_traveler2]

Butch50 wrote:
Wayne, would you please let this post stay in the TC section as they have the most knowledge of the DC compressor fridges.

X TCer here and I have some questions for the folks that have the DC compressor fridges. I'm tired of my Norcold fridge and its poor performance so looking to replace it with a DC compressor unit.

I have room for the Nova Kool RFU6800 6.8 cu ft unit. This would be replacing the Norcold N3160 5.3 cu ft unit Surprisingly the Nova Kool cutout size is a little smaller than the Norcold so I would have to do a little work to make the opening smaller. Do I need to retain as much venting area on the outside of the rig for the Nova Kool as I have for the absorption fridge?

So a question is there any reason to get the Nova Kool with the AC option which adds to the cost of the unit? As far as I can see the AC option is wasted as you still have to convert it back to 12 VDC to run the fridge because the Danfoss compressor is a 12VDC unit. When plugged into shore power why not let the built in converter in the RV provide the DC power to the frdge?

The Nova Kool 12VDC draw is 5.2 amps so I'm changing out my two 12 volt batteries for two 6V Trojans T145s. I can only get 2 batteries into my battery area but I have a lot of height so can fit in the T145s. I would be adding 300 watts of solar minimum before adding the fridge. Do you folks see any reason why this well not work. I'm not a power hog and all of our lights are already LEDs. What is you thoughts on the amount of solar I'm looking at do you think it is enough? When we are out in the woods the TV is never on. M wife has a CPAP but we have a lithium battery for it and it runs her CPAP for 2.5 nights before needing recharging. if we drive at all we plug it into the 12VDC power port to charge it off the vehicle. I'm thinking the 300 watt solar would provide enough power to recharge this battery also for the CPAP.

Thoughts?

Thanks in advance

Butch

Hello Butch50, regardless of what maker of DC compressor refrigerator you go to most of them use the Danfoss DB35 or DB50 compressor and yes it's worth being to be able to use 120 AC volts . I don't know why this is a option with Nova Kool with my Dometic CR1110 is is a stationard built in feature that comes with the Danfoss compressor. I've mine since 2013, just like you I got tried of the constant failures with the absorption system and will never go back to a absorption refrigerator ( Norcold 300.3) Make sure you have the ability to have enought battery power to support that compressor refrigerator. I myself increased the charging wire size and added a Interstate 4D battery to my system and will soon add solar power as well.

Here's a video on my install...CR1110 install

[DWeikert]

Steve_in_29 wrote:

ab257 wrote:
We have a Dometic Tundra compressor fridge (2007), with a Danfoss. The AC is converted to 24 volts DC so it may be more efficient than dining at 12 volts. We had a problem where we were getting a .8 voltage drop across the unit which then kept kicking out on low voltage when on battery. Dometic replaced the board but it didn't help. So they walked me through disabling the AC converter and that solved the problem. Fairly straight forward except powering the light which used a crude step down jury rigged transformer.

So we have been running on 12 volt for the last 8 years using the house inverter when plugged into shore power.

My Tundra is a 2007 model as well and the 110V adapter only works when I physically plug it into the 110V outlet Outfitter installed in the rear of the fridge compartment. Other then that it runs on 12V all the time for me and the interior light works just fine as is.

Likewise my Northstar has an AC outlet in the fridge compartment along with the 12V wiring. My problem was whenever I tried running the inverter the fridge would try running off AC. I just unplugged the fridge from the AC outlet so it only runs on 12V.

[2oldnslow]

HMS Beagle wrote:
Question on the Nova Kool:

2nd, leveling, within any reasonable limit, is not an issue with these?

The Nova Kool spec calls for it to be no more than 30 degrees out of level.

Translation: If your camper is still on its wheels, you are good to go!

I didn't get the 120VAC option on mine, the converter runs it on those rare occasions when I plug in. 300W of solar will be plenty, I run mine plus an Engel cooler (same type compressor) plus a lot of computer usage on 400W.

[Steve_in_29]

HMS Beagle wrote:
Question on the Nova Kool: the 9000 vents inside the RV. This will dump the heat inside, might be good or bad depending on your climate. But it does eliminate a couple of huge holes in the side and roof. Those with inside venting, do you notice the heat?

2nd, leveling, within any reasonable limit, is not an issue with these?

Though it is always good to get things as level as possible the compressor fridges are very forgiving of being a bit out of level as compared to an absorption fridge. As long as you are comfortable with the camper's attitude the fridge will be as well. In fact I intentionally level the camper with a slight left/front lean to allow the water to easily move to the drain that is in that corner of the shower.

I had my Tundra installed with inside venting by Outfitter and the heat is a non-issue. As is the noise, since the camper has to be dead quiet for us to even hear a slight noise and that includes the supplemental fan I installed that only runs when the fridge does to help venting through the closet.

In fact closing off of the outside wall vents with insulation will allow your heater/AC to work better as they aren't fighting the intrusion of ambient temps and wind.

[HMS_Beagle]

Question on the Nova Kool: the 9000 vents inside the RV. This will dump the heat inside, might be good or bad depending on your climate. But it does eliminate a couple of huge holes in the side and roof. Those with inside venting, do you notice the heat?

2nd, leveling, within any reasonable limit, is not an issue with these?

[Geewizard]

Steve_in_29 wrote:

ab257 wrote:
We have a Dometic Tundra compressor fridge (2007), with a Danfoss. The AC is converted to 24 volts DC so it may be more efficient than dining at 12 volts. We had a problem where we were getting a .8 voltage drop across the unit which then kept kicking out on low voltage when on battery. Dometic replaced the board but it didn't help. So they walked me through disabling the AC converter and that solved the problem. Fairly straight forward except powering the light which used a crude step down jury rigged transformer.

So we have been running on 12 volt for the last 8 years using the house inverter when plugged into shore power.

My Tundra is a 2007 model as well and the 110V adapter only works when I physically plug it into the 110V outlet Outfitter installed in the rear of the fridge compartment. Other then that it runs on 12V all the time for me and the interior light works just fine as is.

What Steve said above has been my experience. Replaced my Dometic 3-way with the Tundra and have never ever regretted it.

[Jfet]

We have one of the larger NovaKools in our flatbed camper. Works great, highly recommend. Ours is 9.1cuft and uses about 600 watt hr per day. We did not get the AC option as I saw no need. We do run it on a 24V system but the Danfoss works on 12V or 24V.

[Steve_in_29]

ab257 wrote:
We have a Dometic Tundra compressor fridge (2007), with a Danfoss. The AC is converted to 24 volts DC so it may be more efficient than dining at 12 volts. We had a problem where we were getting a .8 voltage drop across the unit which then kept kicking out on low voltage when on battery. Dometic replaced the board but it didn't help. So they walked me through disabling the AC converter and that solved the problem. Fairly straight forward except powering the light which used a crude step down jury rigged transformer.

So we have been running on 12 volt for the last 8 years using the house inverter when plugged into shore power.

My Tundra is a 2007 model as well and the 110V adapter only works when I physically plug it into the 110V outlet Outfitter installed in the rear of the fridge compartment. Other then that it runs on 12V all the time for me and the interior light works just fine as is.

[Steve_in_29]

Keep in mind, that unlike an absorption fridge running on 12V, the compressor fridges ONLY draw that amp load when they are running. Yes I know the absorption fridge will cycle as well BUT in any kind of heat on 12V (the least efficient mode) it will pretty much run constantly. Even out here in the 100+ degree temps of the desert my compressor fridge runs around one third of the time, with the absolute worst being a 50 percent duty cycle.

Yes you are still going to have to provide venting as the heat needs to go somewhere, just as the heat from your home fridge needs to. The installation instructions for your specific fridge will have the size of vents required. In my case I had my current camper made without the exterior vents (still needed a solid hatch to access the compressor area) and designed an interior vent setup instead. This helps the camper stay warm/cool as there aren't a couple of big holes allowing ambient temps and wind into it.

The 110V option is up to you and it is really just one of those 110V-to-12V converters. It can provide an extra layer of redundancy though as I found out once. I hadn't been paying attention to my solar panels and they had gotten so dirty they were barely charging. Plus it was VERY hot out and thus my batteries had warmed up as well. Because of this when I plugged into shore power the charger kept kicking off due to battery over temp to protect them. So I simply plugged the fridge into 110V and waited until night when things had cooled down enough to allow my batteries to start charging.

My previous camper had the compressor fridge (Tundra 4.2), (2)T145s and 270W solar setup and I ran the fridge constantly for over a year without ever plugging into an outlet. Current camper has same fridge/solar but I added two more batteries (4) Lifeline AGMs this time.

**Thanks mkirsh it was the percent sign apparently.