2020 Northstar Liberty - Expedition Truck Camper Build!

[wyse]

Another person here who has enjoyed your posts and videos. I'm downsizing from an old Northern Lite 8-11Q (sold last Fall) and have a Liberty on order that should be ready in Feb/March. Went with the DC compressor fridge and hoping you could share some insights on how that is implemented. I've read that unlike the propane fridges, the compressor fridges can have gaps that allow wind/dirt/bugs to enter into the inside of the camper.

References below

https://www.truckcamperadventure.com/bugs-and-truck-camper-refrigerator-compartments/

https://www.truckcamperadventure.com/saga-of-the-truck-camper-refrigerator-vent/

Since it looks like you've torn into every nook and cranny I'm wondering what you found with the compressor fridge implementation and if there were gaps, as described in the articles above, and if you did anything to mitigate the wind/dust/bug intrusion (and possibly the propane leaking into the camper you mentioned if the wind was just right) that could result from those gaps.

 

[montypower]

Very exciting! We love our Liberty camper (especially after the modifications). Be sure to share how yours works out!

The Dometic compressor fridge does vent inside. They are designed to be installed in sealed cabinets (no exterior ventilation). NorthStar does include the roof and side vents same as the propane fridges (even if ordering the compressor fridge). Vents are typical. We've run compressor fridges in the Four Wheel Camper and Winnebago View which both had similar exterior vents. It's easier for manufacturers to build all the units the same.

We've removed the fridge many times as all the solar wiring enters the camper through the fridge roof vent. We used some HVAC aluminum tape to seal the fridge vents. Extremely easy. Just around the top and bottom of the mounting flange. Simple solution.

Never had an issue with bugs. And we've traveled all over for years with 3 different camper setups. Window screen could be a simple solution. However, I wouldn't mess with it unless there was an issue. I'm guessing bugs are more of a storage issue or lack of travel. We rarely stay anywhere for more than 5 nights and our campers have always been garaged between travel.

One complaint I have... the propane cabinet isn't vented. It really should have a vent. The cabinet will build gas fumes. I'm planning to eliminate propane so won't be adding a vent.

 

[wyse]

Thanks for the feedback.

"We've removed the fridge many times as all the solar wiring enters the camper through the fridge roof vent. We used some HVAC aluminum tape to seal the fridge vents. Extremely easy. Just around the top and bottom of the mounting flange. Simple solution."

I'm trying to visual all the different "fridge vents" being discussed. When you say you used aluminum tape to seal the "fridge vents" ... It sounds like these are not the roof vent hole or the exterior side vent hole, but rather some kind of other vents around the top/bottom of what you call the "mounting flange". I'm not sure what/where that flange is... is it part of the fridge, or something one needs to remove the fridge to access or can it be accessed without removing the fridge?

I also recall from one of your videos where you had issuess with the fridge door coming open during certain driving conditions. Did you ever solve/fix that issue?

Thanks again for your time.

 

[montypower]

No changes to the exterior vents.

Open the exterior vent and disconnect the fridge power connection(s). The fridge is mounted to the camper via the front/face screws (around the fridge flange). Pull the fridge out. Place it in the dinette area (make sure to have area cleared). On the inside of the fridge mounting flange is where you'll see the vents (top and bottom). It will make sense when you remove the fridge and look at it.

Yes. We resolved the fridge latch by building a latch. We should do an update reviewing and showing everything.

 

[wyse]

https://www.dometic.com/assets/49/30/installation%20and%20operating%20manual_64930.pdf

Does your installation still have the under fridge venting/circulation as shown in Fig 8 of the installation manual? If it does, then without sealing the external side and roof vent openings wouldn't that still allow wind/dust/bugs into the interior?



"The fridge is mounted to the camper via the front/face screws (around the fridge flange)."

Is Fig 10 showing one of the screws to which you refer?

 

[montypower]

You don't need to alter the camper side or roof vents. Dust or bug infiltration is not an issue (as already explained).

The diagram showing air circulation under and above the fridge via the interior is what needs to be taped off. This keeps the exterior camper vents from allowing air to blow inside. Although its extremely minimal.

You'll be taping the top and bottom of the fridge (needs to be removed from the camper cabinet). It will make sense when the fridge is removed.

No the screw diagram is not correct. These are installed with exposed screws around the parameter of the fridge. You can find photos online or watch our camper tour videos to see.

Realistically most people do nothing. It's really a minor deal. But it is easy to resolve.

 

[wyse]

I hadn't watched all of this one of your videos, but now I see you have some good shots of that fridge cabinet with the fridge removed. That is helpful.

 

[wyse]

So, does the fridge sit on, and is surrounded by, that foam insullation material to help isolate the inside of the camper from the side and roof vents? If so, did Northstar build it that way or did you add that?

 

[montypower]

Factory insulation. Yep it's to keep the cold or heat out of the camper space. None of these campers are impressive for insulation. Thin walls. But it does much better than the Four Wheel Camper!

 

[montypower]

We’ve had our share of issues with the 12V DC Compressor fridge installed in our Northstar Liberty truck camper. Our biggest issue has been with the door latch and vents. People have asked many questions about the fridge and we wanted to attempt to cover everything in this video.

How much power does it take?
It draws ~ 5amp DC while the compressor is running. Run time is based on external temperature, internal set temperature, air space inside (more air = less efficient) and door being opened or closed. Assuming the compressor run 20mintues per hour @ 5amps per hour… You’re looking at ~40AH of power per 24hrs. But that number could double to 80AH in HOT weather and frequent door opening. In general, we typically see 20-30amp power drop overnight (including all power uses lights, phone chargers, water pump).

What size battery is recommended?
This depends on your other power needs. We primarily use DC power (no power inverter). 100AH lithium (or 200ah AGM or Lead Acid) battery would be workable for most. But you’d need to recharge within ~24-36hrs. We have 200AH Lithium and power has never been an issue or concern (year round). However, our recent 2,000watt power inverter for charging our e-bikes drastically increased our power usage (especially charging overnight with zero solar).

How much solar do you need?
It depends. 100watt solar panel may produce up to 30AH per day. This is assuming 5+ hours of peak sun (no clouds, no shade). You “may” be able to operate a DC fridge with only 100watts solar in ideal summer conditions with limited or no additional power draws. Our Four Wheel Camper had 200watts of solar with the DC fridge. It was functional in the summer months being careful. It was not good if cloudy, shaded or in the winter. Often the battery would become depleted. Tilting solar panels will help (in the winter) but it’s a hassle (not worth it). My recommendation is 4 to 1 ratio: 400watts of solar for 100AH battery. We run 200AH Lithium batteries with 800watts solar. This ratio generally ensures worry free charging year round in most weather conditions. An alternative charging method like a DC Charger is a good idea (especially when it snows).

We also cover many additional concerns in the video such as proper venting, door latch solution and various comparisons between a Propane absorption 3 way fridge to 12V DC compressor Fridge.

Comment and share things you’ve learned or post any questions you have.

 

[Ultimark]

That looks like the 80 litre version, we have the 110 litre version, same compressor though just works a bit longer. Very impressive cooling capacity, ours has worked well at 47ºC in full sun on a few occasions, although at that temperature the compressor is pretty much running full time.

Neat idea with regard to keeping the freezer door shut, I'll look into doing something like that with ours as we find in hot weather the freezer ices up quickly due to the door not being really shut. Actually the freezer section is a bit of a compromise due to it's quite small size, liveable though.

I seem to remember when we purchased the camper 13 years ago, the shelving had the rear extended tab like thingy in the rear corners, bent a bit more than how it left the factory, which make the shelves a bit harder to extract, they've never slid out like yours seem to do.

Not sure how much dust you get in the back of the refrigerator, but we choked up the original fan with talcum powder like dust from the tracks we traverse. Our slide-on camper was also manufactured with external wall vents for a gas refrigerator, but we insisted on a compressor unit, unfortunately the holes were already cut. We close up the bottom hole in winter, but open it in summer; forgetting on one trip to close it off for some very long dusty tracks.

The WAECO replacement fan is so expensive, so a search found something that has been doing the job for around 5 years now at a fraction of the cost. Just need to get the same air flow to more or less match the OEM fan with the same power draw as the power comes from the internal system.

We've never had the door opening and ours is now atop a truck, which has way harder suspension shudders compared to your utility type of vehicle. Our door is very hard to shut and requires quite a fair amount of pressure to click it shut, usually with a hand and a knee together; floor mounted.

Thanks for the video, quite useful information.

Mick.

 

[montypower]

@Ultimark

Our Fridge is the Dometic CR110 (3.7 CF). It does have a nice modern design and features. The controller seems to work well and is efficient. But they need to resolve their latch system! Seems a simple fix both for the door and freezer. And the shelving could use better retention.

We haven't had much dust accumulation in the fridge compartment. We did tape off the lower two exterior side vents (it's really not necessary to have that much air flow). Will see if dust becomes a factor at some point...

Thanks for sharing!

 

[Ultimark]

Looks are deceiving, we have the same unit CR110 = 110 Litres.

Ours is almost 14 years old. When we purchased it it was in the middle of our winter, which by your standards is mild and warm. We went away as one does, even though it was wet and cold (+5ºC) and found that the refrigerator kept on turning off.

The CR110 is a "T" rated, or Tropical rated refrigerator which is designed to work up to 43ºC and down to 18ºC, below the minimum it basically wouldn't switch back on until the thermometer which is located in-between the inner and outer wall warmed up.

When tested after complaining, it was found to be oscillating between -16ºC to +9ºC in the freezer compartment before switching back on. The fix was a winterising kit which has a small resister (globe actually) which heats up the inside wall directly alongside where the thermometer lay. Once it was winterised, we haven't had an issue and it has had some quite interesting corrugations over long periods.

 

[dayHiker]

Hi all. I just wanted to follow up on my experiences with propane heater last year. Recall, I had elevation issues with the factory propane heater. After many months of complaining, Dometic replaced it last year (spring 2022). But it still had elevation problems. I was ready to take it out and put in a diesel heater. I tried one more idea since I was pretty sure it as a sail switch sensor problem. On all sail switches, there is a metal flat sheet that is designed to catch the air flow to turn sensor on or off. But at high altitude and cold temperature, the air density can be less than half than sea level in the summer. The solution was to slightly bend (about 10 degrees) the metal flat sheet (the sail) into the air flow. This allowed it to catch more air flow and move correctly. It worked great. Tested it up to 11,000 ft and -5F temperature (same time).

I have stayed with the propane heater and there is little condensation even at -5F. Yes, there is moisture at metal door frame and window frames in below freezing temperatures. Also, I use the shower daily, but running vent fan for 20-30 mins afterwards seems to remove moist shower moisture. I understand a lot of folks here feel a diesel heater is dryer, but it is technically not true. Both vented diesel and propane heaters simply heat the air and all combustion gasses (and water vapor) are vented outside. Neither system can add or remove moisture; they can only heat inside cabin air. I am not talking about Buddy heaters that are not vented. To remove water vapor, you need a dehumidifier or keep a vent/window cracked.

 

[montypower]

@dayHiker - Thanks for sharing your experiences! I'm glad it's working well for you.

Our experience is the opposite... Condensation is always a factor freezing and lower (need to wipe the ceiling at the camper nose). We leave the bed windows vented and top roof vent cracked with the heater set at 58 degrees overnight. We have been running a diesel heater for over a year on our 5th wheel trailer. No question. It absolutely dries out the air. Big help especially when cooking with propane (tons of moisture). Still planning to eliminate propane from our camper and go gas or diesel for heat. Just need less projects and more time!