Replacing Refrigerator, vents and wiring questions

[gordinho80]

Yes, I'm replacing my original (non functioning) camper fridge with a residential unit. I know they are not meant for camping, etc, but its going to happen.

I can figure out how to remove the fridge from the unit just fine, I know I'll be cutting off power and disconnecting the propane, now worries. Propane tanks have been disconnected since I parked it 3 months ago.

My questions are regarding the vents, what to do with them? And the wiring for the fridge.

Right now, the TT only has 1 battery. I would like to upgrade the battery bank a bit. I plan on eventually running solar panels on the roof to help with the power situation when dry camping. As it stands, the first several trips out will likely be at a resort with hook ups, so not too worried about those at this time.

I would like the fridge to be one while travelling. This would likely require the fridge be on its own inverter hooked up to the battery (battery bank) that would also be receiving charge from the tow vehicle? Can I accomplish the needed juice to keep the battery charging while towing from the 7 pin trailer plug? Should I look into running thicker gauge power lead from the batter of the tow vehicle into an anderson style plug that would then run to the battery on the trailer?

Who hear has done this already and can you provide some details/specs and pictures if possible?

Thank you.

[Copperhead]

westend wrote:

BadgerMcAdams wrote:
Not sure if you have considered this, but there are 12 volt Danfoss Compressor fridges. They run on 12 volt and I believe 120 volt. They are the fridges that are put in boats and over-the-road trucks. They work just like a regular fridge, and you do not have the leveling problem that is a factor with the propane fridges. Also, they have a low power consumption. Worth a look...

Yup. If you're an owner that is pinching the watts, the 12V fridges draw considerably less power.

I recently saw a guy that had one of those tiny homes and lived off-grid. He had a custom built fridge made from an old chest freezer and had it repiped with something like the 12V Danfoss compressor. He had racks inside that slid back and forth to accommodate access. He loved the **** thing since it just sipped power. Not for everyone but a good food storage solution.

Norcold and Dometic also make AC/DC compressor fridges in various sizes. from small stuff like mentioned on up thru 12 CF units. Typically about a 4AH draw on 12v. I use a Dometic one. It will run for a couple days with my setup and not take down the batteries. I have grown so fond of AC/DC compressor fridges that I will never be satisfied with a absorption type ever again.

[westend]

time2roll wrote:
The existing 12v battery charge line should work fine on the road. Trailer battery may not be full charge when you arrive so plan to plug in or start the generator on arrival.

I would plan on 500+ watts solar and 4+ batteries for dry camping. You will still be running the generator a bit. Most use a 1000w sine wave inverter. You can get a small transfer switch that plugs into the inverter and connect to the existing fridge branch circuit.

Good advice. At present, my single 235w panel and 300AH of batteries keep the small dorm fridge running well. Yes, I have a 1000W inverter. Tried a cheaper 600W PSW and it wouldn't pull the LRD at startup.

I do plan to upsize my solar charging and battery capacity. I want to be able to run completely off grid with a small AC or tank heaters doing their thing. It will take a lot to get to 24/7 perfection but not that much more to get to 75%, I figure. I am planning at least another 235W panel or replace to get around 500W. I will add another pair of 6V's into the bus and that should mean at least four days, maybe five of 120V fridge running, even if the sun doesn't shine.

[time2roll]

The existing 12v battery charge line should work fine on the road. Trailer battery may not be full charge when you arrive so plan to plug in or start the generator on arrival.

I would plan on 500+ watts solar and 4+ batteries for dry camping. You will still be running the generator a bit. Most use a 1000w sine wave inverter. You can get a small transfer switch that plugs into the inverter and connect to the existing fridge branch circuit.

[arkie_guide]

I ran a separate #10 wire from breaker at truck battery to trailer battery. Now I get what the alternator puts our.i also have a switch at the trailer battery so I can disconnect trailer from the battery - better charging.Just add another plug at the truck bumper --- good luck.

[westend]

BadgerMcAdams wrote:
Not sure if you have considered this, but there are 12 volt Danfoss Compressor fridges. They run on 12 volt and I believe 120 volt. They are the fridges that are put in boats and over-the-road trucks. They work just like a regular fridge, and you do not have the leveling problem that is a factor with the propane fridges. Also, they have a low power consumption. Worth a look...

Yup. If you're an owner that is pinching the watts, the 12V fridges draw considerably less power.

I recently saw a guy that had one of those tiny homes and lived off-grid. He had a custom built fridge made from an old chest freezer and had it repiped with something like the 12V Danfoss compressor. He had racks inside that slid back and forth to accommodate access. He loved the **** thing since it just sipped power. Not for everyone but a good food storage solution.

[BadgerMcAdams]

Not sure if you have considered this, but there are 12 volt Danfoss Compressor fridges. They run on 12 volt and I believe 120 volt. They are the fridges that are put in boats and over-the-road trucks. They work just like a regular fridge, and you do not have the leveling problem that is a factor with the propane fridges. Also, they have a low power consumption. Worth a look...

[westend]

gordinho80 wrote:
I don't have the box open yet, but according to the item's description online, the Energy Guide tag shows 329 kWh Estimated Yearly Electricity Use. That is all that is displayed without opening the box itself.

329/365 is about a 1kw/day. If the fridge has a defrost heater or door strip, that can be disabled/turned off for power savings. 1kw/day is typical for a larger sized fridge.
You can read about watt hour rating of batteries here: Guide to lead acid batteries
You'll probably want enough battery capacity to run the fridge for two days, at least, without charging. If you later add solar charging, it is usual to match the amount of charging to the size of the battery bank. Typical solar to battery capacity charging ratio can be 100w of panel to 100AH of storage.

[gordinho80]

I don't have the box open yet, but according to the item's description online, the Energy Guide tag shows 329 kWh Estimated Yearly Electricity Use. That is all that is displayed without opening the box itself.

[westend]

I use a small dorm-sized 120V fridge in my trailer. When 120V shore power is not available, it is powered by a Xantrex 1000W inverter. Power is supplied by 300AH of battery capacity and a single 235W solar panel. The small fridge draws 80W, when operating (considerably more during instantaneous LRD, when starting) In a typical MN Summer,it operates at a 1/4 duty cycle. The compressor draw is about average for 120V fridges, I've found. An owner can calculate draw from the yellow "smart tag" on the new appliance.
I have eliminated the vents that were in the fridge compartment. My small fridge has the cooling fins on the sides and there is no big build up of heat since it resides in an open area underneath a kitchen counter top. Depending on how tight the enclosure is around the fridge, you may wish to leave some passive venting. I'd leave the roof vent since they are difficult to either eliminate or block and heat rises.

My fridge is plugged into the standard duplex receptacle behind it when on shore power or is plugged directly into the inverter when on inverted power.

Everyone's battery bank(s) are different as are vehicle specific trailer charge values. The largest part of operating a fridge from 12V inverted power is having enough battery bank so it will last until sunshine is on the solar panel. For some, that is overnight. For others, it may involve days of bad weather. First step is knowing what the fridge draws.

[2oldman]

This post may be of help.

[GrandpaKip]

I had a dorm size fridge in my cargo trailer conversion. That thing put out a tremendous amount of heat that I had not counted on. I would leave the roof and side wall vents to get the heat out of the camper. And maybe add a fan to help it along.