Nova Kool Conversion Kit Help/Assistance?

[Rlum]

Hi: I need some help with this modification. I will be converting my 3 way refrigerator to compressor with the Nova Kit. 3 plates and Danfoss compressor.

Removing the three system back and just keeping the box. Leaving two good size holes where the old fins are. What is the best way to seal up these holes. I am thinking 1/4 inch thick PVC board? How does one attach it? Glue or screws?

Definitely will be gluing insulation like Polyisol on back and top. Probably 2-4 inches of the stuff.

Any help will be appreciated!

[mkguitar]

Many of us will be interested in this project.


Please document as you go:


procedures, pics, costs, problems and results



GodSpeed !


mike

[Rlum]

Originally Posted by mkguitar

Many of us will be interested in this project.


Please document as you go:


procedures, pics, costs, problems and results



GodSpeed !


mike

Hi: I am not very good at documentation. There is a Travato member on Facebook. I believe his name is Jeff Perkins. He had many problems with his Dometic 3 way. Converted Dometic 3 way to compressor using the Nova Kool conversion kit. Did in depth write and many photos. Actually used and digital controller. Cost him under $1500.00 I am following lots of suggestions but not all. Hope this helps. I will take some photos but Jeff's are a lot better. His write is excellent!

Hope this helps!

[peteco]

Originally Posted by Rlum

Hi: I am not very good at documentation. There is a Travato member on Facebook. I believe his name is Jeff Perkins. He had many problems with his Dometic 3 way. Converted Dometic 3 way to compressor using the Nova Kool conversion kit. Did in depth write and many photos. Actually used and digital controller. Cost him under $1500.00 I am following lots of suggestions but not all. Hope this helps. I will take some photos but Jeff's are a lot better. His write is excellent!

Hope this helps!

Please provide the link. Thanks.

[Rlum]

Originally Posted by peteco

Please provide the link. Thanks.

Hi: It is on the Travato Owners and Wannabees Facebook Page. You will have to join(I believe). Than do a search for Jeff Perkins.

Here is the link: I do not know if it will work since the TOAW is a private group. I just signed up because my PW is made on Ram Promaster and wanted to know what mods they were doing. https://www.facebook.com/groups/trav...65065770341384

All the best

[Rlum]

Originally Posted by Rlum

Hi: I need some help with this modification. I will be converting my 3 way refrigerator to compressor with the Nova Kit. 3 plates and Danfoss compressor.

Removing the three system back and just keeping the box. Leaving two good size holes where the old fins are. What is the best way to seal up these holes. I am thinking 1/4 inch thick PVC board? How does one attach it? Glue or screws?

Definitely will be gluing insulation like Polyisol on back and top. Probably 2-4 inches of the stuff.

Any help will be appreciated!

As a follow up question:

Does anyone know how to dispose of the existing heating unit with ammonia? Will toxic dump stations take this material? Or can it be thrown into trash can?

Thanks

[markopolo]

Originally Posted by Rlum

As a follow up question:

Does anyone know how to dispose of the existing heating unit with ammonia? Will toxic dump stations take this material? Or can it be thrown into trash can?

Thanks

Check to see if there's a rebuild / replacement absorption cooling unit shop near you. They'd probably happily take all the parts you want to get rid of and they'd know how to deal with the ammonia mixture.

[eric1514]

Originally Posted by Rlum

Hi: I am not very good at documentation. There is a Travato member on Facebook. I believe his name is Jeff Perkins. He had many problems with his Dometic 3 way. Converted Dometic 3 way to compressor using the Nova Kool conversion kit. Did in depth write and many photos. Actually used and digital controller. Cost him under $1500.00 I am following lots of suggestions but not all. Hope this helps. I will take some photos but Jeff's are a lot better. His write is excellent!

Hope this helps!

I replaced that refrigerator in my Travato with a NovaKool R3100 and what you're going to do here is better in some ways. The Dometic is nicely equipped with drawers and shelves and lights. The NovaKool I installed was very disappointing in that respect. But in my opinion, there are two things I would do differently than that fellow did.

First off, I would take advantage of the vents that are already cut out in the van. Outside air is almost always cooler than inside air and would be more useful in removing heat from the fridge and that now warm air is better exhausted to the outside of the van, not inside. CO intrusion wasn't an issue before he removed the fridge and it shouldn't be after the unit is properly reinstalled. It wasn't in my case. Also, any additional fans would also be outside of the living space and therefore quieter.

Second. I also used that same remote thermostat and probe but I mounted it outside of the fridge. I always hated opening the door to check on the fridge and with the controller outside the fridge, you can check on the temp and adjust without losing cold air. That switch next to the thermostat is the on/off switch for the fridge.

[Rlum]

Originally Posted by eric1514

I replaced that refrigerator in my Travato with a NovaKool R3100 and what you're going to do here is better in some ways. The Dometic is nicely equipped with drawers and shelves and lights. The NovaKool I installed was very disappointing in that respect. But in my opinion, there are two things I would do differently than that fellow did.

First off, I would take advantage of the vents that are already cut out in the van. Outside air is almost always cooler than inside air and would be more useful in removing heat from the fridge and that now warm air is better exhausted to the outside of the van, not inside. CO intrusion wasn't an issue before he removed the fridge and it shouldn't be after the unit is properly reinstalled. It wasn't in my case. Also, any additional fans would also be outside of the living space and therefore quieter.

Second. I also used that same remote thermostat and probe but I mounted it outside of the fridge. I always hated opening the door to check on the fridge and with the controller outside the fridge, you can check on the temp and adjust without losing cold air. That switch next to the thermostat is the on/off switch for the fridge.

Thanks, On the FB PW forum. One of the members installed a Nova Kool R3102 dedicated refrigerator only. On top of it, he installed a F1900 dedicated freezer. The freezer could be used as refrigerator only. Nice set up. I am planning on using the existing temp sensor controller from NK. I have a remote temp sensor now so no need to open the box to check temps. On top of my unit, am planning on placing as much insulation as possible. Another PW member left the outside vents intact. I asked him if he had only problems with water damaging the compressor? He said in two years, he has not had any problems. So I plan on leaving the vents as they are. If I see potential damage to the compressor, I can always seal it up.

Now I just need to find a place to dispose of heating assembly. If I can find someone who wants one near me. I will gladly give to them if they pick it up. No shipping. I am in Torrance, Ca 90503. Thanks again!

[Roadtrek Adventuous RS1]

Originally Posted by Rlum

Thanks, On the FB PW forum. One of the members installed a Nova Kool R3102 dedicated refrigerator only. On top of it, he installed a F1900 dedicated freezer. The freezer could be used as refrigerator only. Nice set up. I am planning on using the existing temp sensor controller from NK. I have a remote temp sensor now so no need to open the box to check temps. On top of my unit, am planning on placing as much insulation as possible. Another P W member left the outside vents intact. I asked him if he had only problems with water damaging the compressor? He said in two years, he has not had any problems. So I plan on leaving the vents as they are. If I see potential damage to the compressor, I can always seal it up.

Now I just need to find a place to dispose of heating assembly. If I can find someone who wants one near me. I will gladly give to them if they pick it up. No shipping. I am in Torrance, Ca 90503. Thanks again!

Don't know about the R3100....and the shelves?

I had a Nova Kool R3800....3.5 cubic foot refrigerator/freezer ( 3 cubic feet of refrigerator and 1/2 cubic foot freezer installed in my RV to replace the original Dometic 8501 refrigerator/freezer.... best thing I ever did....works beautifully....

I don't know about conversions of an old Dometic..why not just replace your old system and cap off the propane . .

[Rlum]

Originally Posted by Roadtrek Adventuous RS1

Don't know about the R3100....and the shelves?

I had a Nova Kool R3800....3.5 cubic foot refrigerator/freezer ( 3 cubic feet of refrigerator and 1/2 cubic foot freezer installed in my RV to replace the original Dometic 8501 refrigerator/freezer.... best thing I ever did....works beautifully....

I don't know about conversions of an old Dometic..why not just replace your old system and cap off the propane . .

Hi: My Dometic actually is fully functional. I am replacing all of the shelves with the wire variety for better circulation. I have three fans inside the box and two outside. I like the look of the Dometic because it fits the cabinetry. The PW lexor does not have the drawers like the Travato. Nova Kool is a better refrigerator(my opinion) but the cost of purchasing the R3102 and F1900 is over $2500. Dometic just came out with a compressor unit(not Danfoss compressor and only in 12volt). RCL 10.4T? It is identical to my rml 8330. The RCL is a compressor model and the rml is three way. RCL is over $2500 without shipping and currently only available in Europe and Australia? The conversion kit is under 1K(Danfoss compressor in both 12/110volts). So I will try this first.

Capping off the propane on a functional three way is to remove the most efficient modality. I currently prefer propane because it keeps the refrigerator the coldest of the three modalities. Just came back from trip. The ambient temp was over 100F. Looking forward to only using 12volt on the Danfoss compressor unit.

[Roadtrek Adventuous RS1]

You're going to love the Danfoss compressor. It's an extremely efficient low energy device that is very quiet.

My old Dometic 8501 had a lot of problems;

1. When they removed it from my RV ( yes, it was expensive and I had this professionally done) they discovered burnt wires on the top of the old unit about 4 or 5 inches from the propane flame....You know, had that ignited and started burning it's possible that I wouldn't still have my RV. Glad that's gone... and my propane tank supply for the old refrigerator is capped off.

2. Very inconsistent cooling... temperatures would vary greatly depending on how hot it was.

3. Stopped working in higher elevations...We went to the North Rim of the Grand Canyon.... approximately 9,000 feet....jets would not fire....Of course I got back home and the owner's manual said... not designed to work above 3,250 feet....I felt like a dummy for missing that.

4. Wouldn't cool on battery....I discovered that it's not supposed to do anything except maintain temperature on the battery mode, so, every time we opened the refrigerator door it just got warmer inside the unit...

5. Last time it was working on electricity, I was plugged in and while it finally got cold, I noticed water leaking on the floor.....



By this time I had had it ...... the whole thing had to go.....

I wish you luck on your project..... and Happy July 4th...

[ripaco]

I replaced my Dometic 3-way with a Nova Kool 4500 about 3 years ago. The conversion was fairly straight forward if you are handy. Before installation I called Nova Kool and they said the refrigerator should definitely be vented to the inside of the coach because it is designed to have conditioned indoor air for the condenser coil. Outdoor air can vary from 0 to over 100 degrees if you camp year round. I covered the inside of the louvered vents with 1" flexible closed cell foam and taped the foam securely with foil tape to hold the foam in place and cover any air gaps. I then covered the left and right sides, and top and bottom of the refrigerator with 1" rigid R5 foam. It is important to provide the recommended amount of venting for the condenser coil. Nova Kool requires 30 square inches for inlet and 30 square inches for outlet air. I used the existing wiring that supplied the Dometic. The hot wire was 12 ga and the neutral 14 ga. The length was unknown. While dry camping on multiple cloudy days without much solar, my house battery dropped to 10.6 volts and the refrigerator shut off. The compressor has a feature to shut off at 10.4 volts and come back on at 11.7. I measured a 0.2 voltage drop from the battery to the refrigerator. Replacing the existing wiring of unknown length with 3 feet of wiring (with 15A inline fuse) eliminated voltage drop.

The Nova Kool thermostat sensor senses and maintains only the freezer temperature. This allows the refrigerator temperature to vary with the temperature inside the coach. The warmer the coach, the warmer the refrigerator. So I have to keep an eye on the refrigerator temperature and adjust the thermostat as necessary.

If you do much dry camping I suggest solar panels. Without, the battery will drain fairly quickly. I have 200 watts of solar with 220 AH of Lifeline AGM house battery and this keeps the batteries up for days of dry camping provided there is mostly sunny weather. As I mentioned, if your battery drops below 10.4 volts the refrigerator will shut off.

[Rlum]

Originally Posted by ripaco

I replaced my Dometic 3-way with a Nova Kool 4500 about 3 years ago. The conversion was fairly straight forward if you are handy. Before installation I called Nova Kool and they said the refrigerator should definitely be vented to the inside of the coach because it is designed to have conditioned indoor air for the condenser coil. Outdoor air can vary from 0 to over 100 degrees if you camp year round. I covered the inside of the louvered vents with 1" flexible closed cell foam and taped the foam securely with foil tape to hold the foam in place and cover any air gaps. I then covered the left and right sides, and top and bottom of the refrigerator with 1" rigid R5 foam. It is important to provide the recommended amount of venting for the condenser coil. Nova Kool requires 30 square inches for inlet and 30 square inches for outlet air. I used the existing wiring that supplied the Dometic. The hot wire was 12 ga and the neutral 14 ga. The length was unknown. While dry camping on multiple cloudy days without much solar, my house battery dropped to 10.6 volts and the refrigerator shut off. The compressor has a feature to shut off at 10.4 volts and come back on at 11.7. I measured a 0.2 voltage drop from the battery to the refrigerator. Replacing the existing wiring of unknown length with 3 feet of wiring (with 15A inline fuse) eliminated voltage drop.

The Nova Kool thermostat sensor senses and maintains only the freezer temperature. This allows the refrigerator temperature to vary with the temperature inside the coach. The warmer the coach, the warmer the refrigerator. So I have to keep an eye on the refrigerator temperature and adjust the thermostat as necessary.

If you do much dry camping I suggest solar panels. Without, the battery will drain fairly quickly. I have 200 watts of solar with 220 AH of Lifeline AGM house battery and this keeps the batteries up for days of dry camping provided there is mostly sunny weather. As I mentioned, if your battery drops below 10.4 volts the refrigerator will shut off.

Thanks for information. I am planning on using Poly isol for insulation(1 inch) As many layers as I can glue onto back and top. Sides fit cabinet too tightly. Other people have changed thermo sensor/controller unit to a Dyer? I will keep the Nova Kool for now. Use a remote temp sensor so I can check temp without opening frig. Use three internal box fans to circulate air inside box. Now I will not have any air from inside. All of the air to cool compressor will be from outside vents. (both are 12 X 5 inches). Temps can get hot where I go(100+F)? Will use existing electrical for 12 volt. I believe PW wired properly for 3 way Dometic. So use the existing 12 volt source.

Not too worried about electrical. Have 195 watt solar and 800Ah lithium bank. Run AC for several hours from Victron 12/3000 inverter. Wife does not like hot weather, Ha, ha.

[Roadtrek Adventuous RS1]

Originally Posted by ripaco

I replaced my Dometic 3-way with a Nova Kool 4500 about 3 years ago. The conversion was fairly straight forward if you are handy. Before installation I called Nova Kool and they said the refrigerator should definitely be vented to the inside of the coach because it is designed to have conditioned indoor air for the condenser coil. Outdoor air can vary from 0 to over 100 degrees if you camp year round. I covered the inside of the louvered vents with 1" flexible closed cell foam and taped the foam securely with foil tape to hold the foam in place and cover any air gaps. I then covered the left and right sides, and top and bottom of the refrigerator with 1" rigid R5 foam. It is important to provide the recommended amount of venting for the condenser coil. Nova Kool requires 30 square inches for inlet and 30 square inches for outlet air. I used the existing wiring that supplied the Dometic. The hot wire was 12 ga and the neutral 14 ga. The length was unknown. While dry camping on multiple cloudy days without much solar, my house battery dropped to 10.6 volts and the refrigerator shut off. The compressor has a feature to shut off at 10.4 volts and come back on at 11.7. I measured a 0.2 voltage drop from the battery to the refrigerator. Replacing the existing wiring of unknown length with 3 feet of wiring (with 15A inline fuse) eliminated voltage drop.

The Nova Kool thermostat sensor senses and maintains only the freezer temperature. This allows the refrigerator temperature to vary with the temperature inside the coach. The warmer the coach, the warmer the refrigerator. So I have to keep an eye on the refrigerator temperature and adjust the thermostat as necessary.

If you do much dry camping I suggest solar panels. Without, the battery will drain fairly quickly. I have 200 watts of solar with 220 AH of Lifeline AGM house battery and this keeps the batteries up for days of dry camping provided there is mostly sunny weather. As I mentioned, if your battery drops below 10.4 volts the refrigerator will shut off.

Understood. Yes, the refrigerator will turn off with low power.

I have twin 6 volt 224 AH Full River AGM's and 275 watts of solar, plus a Victron BMV 712, I don't run out of power with the refrigerator on 24/7 even when we're not plugged in. As a matter of fact, the RV has never gone below a 70 percent state of charge.

There's a significant difference in the power to run the R3800 and the R4500.
The smaller unit uses 2.2 amps per hour when it's running and the R4500 uses 4.4, that's double the power.

Is your battery system using one 12 volt battery or two 6 volts in series?

It's all about how you use your RV electronics and we're very careful not to use too much and only turn on the inverter during the day to charge our cell phones. We stream using the laptop at night and have mostly all LED fixtures inside. We could still use the 120 volt TV or sound system if we wanted to.

On most days, the two roof mounted 275 watts of solar charge up the coach batteries by mid morning and we don't over use the heating system ( the fan that runs the propane heater is the other major draw). So, we're mostly just on the 12 volt system all of the time.

Whenever we're driving the RV, the house and the starting battery are all charging. If that's not enough I have an onboard generator to charge up the system. If I want to run the air conditioning or microwave convection oven, I need to fire up the generator anyway.

I keep the refrigerator on all of the time, it's easy and I don't have to worry about mildew or anything else in the unit. Nova Kool is a marine refrigerator and can operate off level up to 30 degrees and while it's possible, I cannot imagine sleeping at anything over a few degrees, but, I'm never overly concerned about leveling the coach.

We get plenty of charging even on cloudy days, so, it doesn't have to be full sun to get charged up.

See the attached spec sheet on Nova Kool

[ripaco]

The 3800 and 4500 have the same compressor. The compressor speed is adjustable (not variable as Nova Kool says) by adding a resistor between the thermostat and terminal C on the compressor controller which they do at Nova Kool I expect. It is adjusted to a higher speed (greater resistance) on the 4500. I replaced the resistor with a rheostat to experiment with the speed. In cooler weather I can run it at a lower speed. The greatest efficiency and lowest battery usage is achieved by running the compressor longer and at lower speed. Of course the 2.2 and 4.4 amp draws shown in the Nova Kool literature vary as conditions vary as with any refrigeration system. I measured the resistor that my 4500 came with at just under 500 ohms. Their spec sheet shows that the compressor RPM would be around 2730. With the freezer at -20C (0F), the amp draw according to their spec sheet should be about 3.4. This is close to what I see with a temperature of 70F in the coach. Higher temperature in the coach = higher amp draw because of higher condensing temperature. The Danfoss technical information shows that the compressor ratings are at a condensing temperature of 55C (131F). This is probably at an ambient temperature of 90+ F since the condensing coil is cooled only by natural convection and has no fins. At this temperature, the compressor would probably draw 4.4 amps as the literature says.

[booster]

I have preached for a long time on the forum that the "rated" which are really running amps mean very little in the big picture of daily use as it changes with compressor speed in particular. Watt hours per day is much better if run under the standard test procedures like Isotherm does.


A careful look at the compressor maps showed me that the second speed is probably the most efficient in the BD35 if you look at Btu/hr removed vs watt/hr used, but it isn't huge. The explanation is in another discussion.


Slowing down the compressor usually will give you a colder freezer and warmer frig at the same mechanical thermostat setting, depending on the probe placement.



The in frig section electronic thermostats are much better I think, and we soon will have a chance to test the latest Isotherm energy saving version which has gotten good reviews. Our 10 year old Isotherm cruise 85 started giving us grief on the last trip with running warm and wide hysteresis and it is so old the good controls can't be added to it, so we have a new one of the same model coming. I think the old one has a dead compressor/condenser cooling fan on it based on the way it was running, so probably fixable and probably salable.