Typical 3 way fridge vs. what y'all are buying for your van....

[Bster13]

I've watched and read about similar refrigerators for a van like this video:


Here Bob states the fridge(s) can be run off solar.  Nuff said.

But if you watch or read about the typical fridge in an RV, folks are always running them off propane as folks state they will drain your house batteries very quickly.

Are these fridges used in vans that much more efficient?  What gives?  Thanks!

 

[johnny b]

Propane fridges cool via the 'absorption cycle'.
A propane fueled burner heats an ammonia solution to circulate thru fridge to remove heat. It is a gravity system and requires a very level unit to avoid damage...ie. can't park on uneven surface very often without risking damage.
When running on 12 volts, a heating element does what the propane flame was doing....constantly on.
The propane fridge needs an exhaust vent due to the burning flame. If the flame goes out, propane hopefully is being drawn out the vent.

A 12 volt 'compressor' fridge as referenced in Bob's video only draws power when the compressor is running. It cycles off and on just like your home fridge. Insulate around it in warm weather to reduce the amount of time the compressor runs.

Both types of units have been around a while and work very well. The two-way and three-way units were pretty much designed for when campers would drive to their site, set camp and not move til going home. Propane worked well when no shore power was available.

The 12 volt compressor fridges became popular with the more adventurous camper who boondocked more and with the increased use of solar to keep batteries charged up.

Propane fridges require a bit more maintenance, don't 'cycle' when on electric, and must be kept level.
12 volt compressor fridge is more frugal with its cycling of power, is basically maintenance free, and most can handle up to a 30 degree tilt.

hope that helps.

 

[highdesertranger]

when I was trying to get off of ice I tried the propane refer. it worked well but instead of having to go get ice I was having to go get propane. now I could have gotten bigger tanks but you still have to refill them. with the 12v compressor units after the initial investment you have unlimited free refrigeration. highdesertranger

 

[VanForNow]

Propane fridges cool via the 'absorption cycle'.
A propane fueled burner heats an ammonia solution to circulate thru fridge to remove heat. It is a gravity system and requires a very level unit to avoid damage...ie. can't park on uneven surface very often without risking damage.

I  have seen some big A & c rigs which have special leveling mechanisms. Can vans be leveled in a similar manner to help preserve propane fueled fridges?

 

[BradKW]

But if you watch or read about the typical fridge in an RV, folks are always running them off propane as folks state they will drain your house batteries very quickly.

I suspect that the "typical fridge in an RV" is not a 12v fridge that you see talked about on this site if it's draining batteries. 12v fridges with a Danfloss compressor are very efficient...I think it's probably fair to say that even a 200 watt solar system will handle any fridge 24/7. I've seen people say that they run smaller fridges off 100 watts.

Many RVs are designed with large appliances that are meant to be powered by a) shore power, b) generator, or c) propane. They use propane because there's already a under-chassis tank and they don't have to size a solar system to meet the appliance needs.

If I were starting from scratch, and coincidentally I am, I wouldn't even consider propane for fridge, just no reason to...

 

[Bster13]

Propane fridges cool via the 'absorption cycle'.
A propane fueled burner heats an ammonia solution to circulate thru fridge to remove heat. It is a gravity system and requires a very level unit to avoid damage...ie. can't park on uneven surface very often without risking damage.
When running on 12 volts, a heating element does what the propane flame was doing....constantly on.
The propane fridge needs an exhaust vent due to the burning flame. If the flame goes out, propane hopefully is being drawn out the vent.

A 12 volt 'compressor' fridge as referenced in Bob's video only draws power when the compressor is running. It cycles off and on just like your home fridge. Insulate around it in warm weather to reduce the amount of time the compressor runs.

Both types of units have been around a while and work very well. The two-way and three-way units were pretty much designed for when campers would drive to their site, set camp and not move til going home. Propane worked well when no shore power was available.

The 12 volt compressor fridges became popular with the more adventurous camper who boondocked more and with the increased use of solar to keep batteries charged up.

Propane fridges require a bit more maintenance, don't 'cycle' when on electric, and must be kept level.
12 volt compressor fridge is more frugal with its cycling of power, is basically maintenance free, and most can handle up to a 30 degree tilt.

hope that helps.

Definitely helps, great explanation.  With that said, do they make "upright" compressor fridges to fit in the space of a typical 3-way found in an RV?  Trying to find a balance on what vehicle to buy and the GF ~might~ go for a class B, but I'd like to know if there are options to replace the fridge with a more efficient setup.  Thanks!

 

[highdesertranger]

for the smaller units yes they make a replacement 12v unit. highdesertranger

 

[Bster13]

Possibly one size to fit in a Castia or Scamp?

 

[SternWake]

Vitrifrigo, NovaKool, Dometic, Truckfridge and Norcold all make upright, front loading, 12v compressor fridges. These might be 12vDC and 120vAC, or just 12vDC depending on model.

The DC only models might be significantly cheaper or just marginally so.

Norcold and Dometic also make Absorption/propane/3 way and 2 way( propane and 120vAC) fridges

While 3 way fridges can run on 12v, they are absorption fridges, not compressor.
Absorption fridges use huge amounts of electricity on 120 or 12v. Not much of a factor on AC but will quickly depleted a battery

 

[highdesertranger]

Engel makes them to. they also make drop ins. they also make conversion kits and build your own kits. highdesertranger

 

[blars]

Absorption fridges do cycle on and off. However, they are not efficient and usually the 12v mode is only for holding so will run almost continuously. I have run my 2-way off an inverter when I had pleanty of solar available.

 

[SternWake]

The modern absorption fridges also use 12vDC to power the circuit board while it monitors temp, and controls the propane
. On another forum a poster claimed this was 16Ah per 24 hours.
Below 70F ambient , my extra insulated 1.8 cubic foot vitrifrigo rarely uses more than this much juice, in my usage.

Extra insulation and making sure the cooling unit's condenser/compressor is properly ventilated can significantly reduce electrical consumption.

Compressor fridges with Danfoss/secop compressors allow one to easily add another computer fan to assist heat removal from cooling unit.