Refrigerator

[booster]

Originally Posted by Gagroot

Considering the conversion to a compressor fridge sounds like a big move, it's wise to seek expert advice.

Like so many things related to RV stuff, I think that the swap to compressor frig could be more appropriately put into the "it depends" category.


It can be relatively hard to do and expensive but also may not be very tough at all to do.



That difference depends a lot on how you use your van and how you plan to use your van. Use and driving patterns differences between users makes a huge difference.


What your current van and electrical system are currently also is a big deal in determining what you would be facing.


I wouldn't dive into a swap until the two things were evaluated as it would a shame to pass on a compressor frig for the wrong reasons. We have had a compressor frig for a over a decade and never would go back because of how well they work compared to the absorption versions.


This forum has lots of discussions of many users swaps to compressor frigs with essentially of them working out well.


You may want to start a thread of your own where you can list out how you use the van and what the systems are currently. Lots of help available here.

[roadbot]

Our experience with small compressor refrigs in hotels is annoying cycle on/off sleep disturbing noise, to extent we normally unplug the hotel units. Yet none of the posts I have seen on absorption to compressor refrig conversion mention operating noise levels. Anyone have input on the noise factor? Thanks

Also, most relevant posts on this conversion topic suggest one has to convert AGM to lithium to support compressor style refrigs. For a 210P with solar and UHG, wouldn't just increasing two AGM to four serve the compressor under most situations?

[booster]

Originally Posted by roadbot

Our experience with small compressor refries in hotels is annoying cycle on/off sleep disturbing noise, to extent we normally unplug the hotel units. Yet none of the posts I have seen on absorption to compressor refrig conversion mention operating noise levels. Anyone have input on the noise factor? Thanks

Also, most relevant posts on this conversion topic suggest one has to convert AGM to lithium to support compressor style refrigs. For a 210P with solar and UHG, wouldn't just increasing two AGM to four serve the compressor under most situations?

You don't need lithium to run a compressor frig. We ran our on two wet cells, 3 wet cells, 4AGMs, and now lithium and they all worked just fine as long as you had enough amp hours to cover your timeframe.

[avanti]

Originally Posted by roadbot

Our experience with small compressor refries in hotels is annoying cycle on/off sleep disturbing noise, to extent we normally unplug the hotel units. Yet none of the posts I have seen on absorption to compressor refrig conversion mention operating noise levels. Anyone have input on the noise factor? Thanks

Also, most relevant posts on this conversion topic suggest one has to convert AGM to lithium to support compressor style refrigs. For a 210P with solar and UHG, wouldn't just increasing two AGM to four serve the compressor under most situations?

Most of the RV compressor fridges use small, efficient fully-sealed compressors made by Danfoss. These DC units have sealed, brushless motors driven by fancy electronics and can operate at variable speeds. They are extremely quiet.

Yes, you can certainly run such a fridge with four AGM batteries. In our previous rig, I had four 110Ah (12V) batteries, and they were more than enough to run the fridge and all our other loads.

Honestly, nobody REALLY needs lithium unless they aspire to running the A/C without shore power.

[hbn7hj]

Originally Posted by roadbot

Our experience with small compressor refrigs in hotels is annoying cycle on/off sleep disturbing noise, to extent we normally unplug the hotel units. Yet none of the posts I have seen on absorption to compressor refrig conversion mention operating noise levels. Anyone have input on the noise factor? Thanks

Also, most relevant posts on this conversion topic suggest one has to convert AGM to lithium to support compressor style refrigs. For a 210P with solar and UHG, wouldn't just increasing two AGM to four serve the compressor under most situations?

A person changing from a propane fridge to a compressor fridge will notice the noise but you can get used to it.

[GeorgeRa]

I have a fridge with a Danfoss compressor, the loudest component was electromechanical thermostat. I replaced it with electronic thermostat which is deadly quiet. I also replaced its fan with a very quiet cooling one and its noise is almost not detectible.

[Blueboy1]

Keypoint of a good installation is the attention one has to give to proper insulation and the secondary benefit of such attention is the muting of the compressor motor. We have a Novakool 12VDC only since 2018 and sometimes I do have to listen very carefully to make sure that it is running . I do agree that you can hear the click of the thermostat on startup but it is marginal. Running well with 250watts panel and 215A wet cell Trojan battery. Average power drain on the night period is 150 watts. Again, insulation reduces the cycling.

[booster]

Originally Posted by Blueboy1

Keypoint of a good installation is the attention one has to give to proper insulation and the secondary benefit of such attention is the muting of the compressor motor. We have a Novakool 12VDC only since 2018 and sometimes I do have to listen very carefully to make sure that it is running . I do agree that you can hear the click of the thermostat on startup but it is marginal. Running well with 250watts panel and 215A wet cell Trojan battery. Average power drain on the night period is 150 watts. Again, insulation reduces the cycling.

All true and similar to many, especially adding extra insulation if there is space.


I assume you mean 150 watt hours of power use? Converts to about 12.5 amp hours for those that keep track that way. 24 hour use probably closer to 40ah or 480wh?

[Blueboy1]

Originally Posted by booster

All true and similar to many, especially adding extra insulation if there is space.


I assume you mean 150 watt hours of power use? Converts to about 12.5 amp hours for those that keep track that way. 24 hour use probably closer to 40ah or 480wh?

You are right, but the 150 watts (or VA if you prefer)is the total energy drain from the battery on a typical night period. I do not take in consideration the daylight period as there is actually no power drain from the battery , the solar panel taking care of all power requirement. I do appreciate your insight. Have a nice day

[GeorgeRa]

Originally Posted by Blueboy1

You are right, but the 150 watts (or VA if you prefer)is the total energy drain from the battery on a typical night period. I do not take in consideration the daylight period as there is actually no power drain from the battery , the solar panel taking care of all power requirement. I do appreciate your insight. Have a nice day

Watt is a unit of power and Watt-Hour is a unit of energy. Our home electricity bills are in $/Whr not in $/W which would be meaningless. In RV world w measure energy in Ahr assuming 12V system, it should be VAHr as you pointed earlier.

[booster]

Originally Posted by Blueboy1

You are right, but the 150 watts (or VA if you prefer)is the total energy drain from the battery on a typical night period. I do not take in consideration the daylight period as there is actually no power drain from the battery , the solar panel taking care of all power requirement. I do appreciate your insight. Have a nice day

As George said, neither watts or VA are units of energy because they are instantaneously read power units. You have to have a time period with them for energy so watt hours.

You have the same in the post in relation to the battery capacity when you say a 215 amp battery as amps aren't energy capacity and needs the time period like with the watts, and also lacks the voltage. With time added it gets to be 215 amp hours which traditionally has been the rating used for battery capacity with the caveat that they don't include the voltage so isn't really total energy without it. We do see quite a bit more times that batteries are rated in watt hours, especially with lithium in the higher voltage systems. The amp hour rating probably should go away these days as systems have so many different voltages it is pretty irrelevant a lot of the time. Throw in electric vehicles and it gets even worse.

Much of this confusion started with RV manufacturers using amps instead of amp hours to try to make the battery systems in their van appear larger than they really were. Take a battery with 100 amp hours of capacity and call it a 600 amp battery because that is what the cold cranking amps are for it. The non technical public thinks it is the same as a real 600 amp hour bank and gets to be really unhappy when the don't get enough capacity in their new RV.

[sparkyfourhire]

Originally Posted by Infohound

We boondock a lot. He says the lithium battery would give us about two days of service before needing recharging. He says we would need to run our generator 8 to 12 hours to fully recharge.

My questions to this situation is: What does "We boondock a lot" mean? Do you overnight without shore-power, but drive around during the day? Do you park under a bunch of trees and not move for days on end? I don't think the fridge power usage and the battery system upgrade are directly proportional, but rather dependent on how you use the system and recharge it. That includes what other electrical drains there are on the battery system between charges, such as fans, TVs, lights, cooking, water pump, etc.

Assuming everything else has been functioning for you just fine, then you just need to consider how much battery power a 12v fridge would use between your normally longest interval between charges, and how much charge you are getting each time (just solar vs short or long drives vs generator). Perhaps just a larger or second battery for your existing system might suffice for far less than a lithium upgrade.

[Doneworking]

I seem to be more lucky than most with the original three way 5 cf refrig in our 2007 210P Roadtrek. We are getting it ready now for a trip and I just plugged it in Friday morning and turned on the 110 volt setting. This morning, it is 32F in the refrig. Going down the road in this hot climate (100 and above for several days) I will switch it over to 12v and the temps will get up into the low 40s until we get to our first destination. Then, back on 110v or gas and back into the high 30s. Going down the road we put the 1-5 settings on 5 (max). Once camped, we usually put it on 3.

We keep a small indoor outdoor wireless thermometer in the refrig and the receiver is mounted with velcro on the dash. We monitor the temp to make sure all is well.

Perhaps our good luck is because we bought this unit new eighteen years ago, keep it an enclosed garage and maintain it ourselves. We are picky about leveling the RT properly and I am sure that is a benefit to the efficiency of the refrig.

I know lots of people that really take care of their rigs and have lots of trouble with these old refrigerators so I can just assume we are unusually lucky.

[MsNomer]

This “and the temps will get up into the low 40s until we get to our first destination” and all the switching would be a deal killer for me.

[GeorgeRa]

Originally Posted by Doneworking

I seem to be more lucky than most with the original three way 5 cf refrig in our 2007 210P Roadtrek. We are getting it ready now for a trip and I just plugged it in Friday morning and turned on the 110 volt setting. This morning, it is 32F in the refrig. Going down the road in this hot climate (100 and above for several days) I will switch it over to 12v and the temps will get up into the low 40s until we get to our first destination. Then, back on 110v or gas and back into the high 30s. Going down the road we put the 1-5 settings on 5 (max). Once camped, we usually put it on 3.

We keep a small indoor outdoor wireless thermometer in the refrig and the receiver is mounted with velcro on the dash. We monitor the temp to make sure all is well.

Perhaps our good luck is because we bought this unit new eighteen years ago, keep it an enclosed garage and maintain it ourselves. We are picky about leveling the RT properly and I am sure that is a benefit to the efficiency of the refrig.

I know lots of people that really take care of their rigs and have lots of trouble with these old refrigerators so I can just assume we are unusually lucky.

I have experience with 5 absorption refrigerators in different RVs and had no issues. But, leveling was always a part of setting of campsites. On the Bigfoot trailer I built airbag leveling to simplify this task. Since choosing diesel as a primary fuel, I switched to compressor (Danfoss based Isotherm), it was great to skip leveling but Danfoss electronic module driving the compressor had to be replaced.

So, for me the comparison is diesel space/water heating vs levelling, if I start another build I would likely stay with LPG, I know this is not trendy but I in the recent replacement of over 11 years old AGMs I bought the same but new AGMs, not lithium.

[91Roadtrek]

I replaced the Dometic RM2333 in our 1999 Coach House with a Norcold DC105 (12 volt only compressor fridge). It only draws a few amps and we have 200ah of LiFePO4 batteries. There are not that many of them out there (may be discontinued), but I bought from here and the cost, with shipping, was around $1,050.

Here's a link to what I got: https://marinepartssource.com/3-3-cu...-norcold-dc105