Jan-15-2022 07:21 AM
Jan-07-2023 01:27 PM
Jan-06-2023 10:01 AM
Fisherguy wrote:I have what most would consider to be a healthy solar/battery system. But if I were to add a 12V fridge to the draw, I would come up short a lot.... And adding to what already have is not so easy. It would be quite expensive, and make my roof so full that I would not have room to do maintainence up there.
Jan-06-2023 09:58 AM
Jan-06-2023 06:15 AM
Jan-06-2023 03:15 AM
valhalla360 wrote:I have what most would consider to be a healthy solar/battery system. But if I were to add a 12V fridge to the draw, I would come up short a lot.... And adding to what already have is not so easy. It would be quite expensive, and make my roof so full that I would not have room to do maintainence up there.Grit dog wrote:
9 pages later, ^ here’s a good dose of common sense and truth.
Being more “efficient” in one way doesn’t necessarily mean less costly.
Sure both have different advantages and disadvantages but apples to apples, especially if considering replacing a perfectly good absorption fridge, it’s not even close.
Truth depends heavily on the assumptions.
Tearing out a relatively new perfectly functional appliance rarely makes sense, no matter how bad the existing technology is. Are you going to rip out the perfectly functional 5 speed transmission in your truck and retrofit one of the new 10 speed units because it's better...of course not. It's a silly comparison.
If you are boondocking a lot with a single 12v starting battery and no solar, yeah, absorption is by far the better option but that's not a typical use pattern.
Vast majority of RVs rarely operate away from shore power. For these rigs, 12v compressor fridges are better both in terms of efficiency but also in terms of better operation (faster cooldown, able to hold colder temps, larger interior volume, etc....). I'm betting this represents 80-90% of new RV buyers, so this is where the manufacturers are focused.
For those who do a lot of boondocking, most will be installing a larger battery bank and solar anyway. Up sizing it to accommodate the relatively modest requirements of the 12v fridge is easy and doesn't incur a major cost. The cost difference between installing a couple of 200w panels and a couple of 300w panels, is pretty minimal. A few seasons of reduced propane use will cover the cost.
Jan-05-2023 04:30 PM
valhalla360 wrote:Grit dog wrote:
9 pages later, ^ here’s a good dose of common sense and truth.
Being more “efficient” in one way doesn’t necessarily mean less costly.
Sure both have different advantages and disadvantages but apples to apples, especially if considering replacing a perfectly good absorption fridge, it’s not even close.
If you are boondocking a lot with a single 12v starting battery and no solar, yeah, absorption is by far the better option but that's not a typical use pattern.
For those who do a lot of boondocking, most will be installing a larger battery bank and solar anyway. Up sizing it to accommodate the relatively modest requirements of the 12v fridge is easy and doesn't incur a major cost. The cost difference between installing a couple of 200w panels and a couple of 300w panels, is pretty minimal. A few seasons of reduced propane use will cover the cost. Manufacturers are still on the learning curve but they are starting to outfit RVs with solar options. Not just for the fridge but for other convienences.
Jan-05-2023 09:05 AM
Jan-05-2023 12:04 AM
Grit dog wrote:
9 pages later, ^ here’s a good dose of common sense and truth.
Being more “efficient” in one way doesn’t necessarily mean less costly.
Sure both have different advantages and disadvantages but apples to apples, especially if considering replacing a perfectly good absorption fridge, it’s not even close.
Jan-04-2023 09:36 PM
ktmrfs wrote:StirCrazy wrote:
when it comes to power usage, a 12V is not near as energy efficient (battery power wise) as an adsorbition fridge. you will need much more battery capacity and solar or a generator if you switch to 12V compressor.
In terms of BTU or KWH needed to cool, compressor driven fridges are much more efficient than a absorption fridge. Generally you can get about 3x the input BTU used in cooling BTU from a compressor driven fridge. No it doesn't violate any laws of physics, it's the energy needed to move heat from one place to another.
By contrast an absoprtion fridge is much less efficient COP is on the order of 0.7 or less vs 3 or more for compressor fridges.
But in terms of how the energy is stored to use the fridge, propane in BTU/gallon or BTU/weight or BTU/volume FAR FAR FAR exceeds any battery for the same volume or weight.
Jan-02-2023 02:29 PM
Jan-02-2023 02:17 PM
Reisender wrote:
Yah I hear you. Hence our back up plan with our little propane generator. :).
Jan-02-2023 08:11 AM
Vintage465 wrote:Fisherguy wrote:Vintage465 wrote:
... The day will come when everything will be 12v compressor and we will all need to adjust and by that time the solar and batteries will surely be up to the task.
And on that note I'm looking for advice. I have a chance to buy a trailer with 600 watts of solar panels, 3 - 100 Ah Lithiums and a 12 volt Norcold fridge.
I'll be installing a small inverter to power the TV and sat dish but no coffee makers or toasters etc for us.
If we only boondock do you think this setup will work for us? Maybe if I add another 200 watt panel and another 100Ah of Lithium?
We only very rarely need to run the genny to charge batteries with our current rig in my signature.
Thx
I think you have a good start there, but I'm certainly not any kind of expert on 12v longevity from a power stand point. But based on what you have and are willing to add to it you should be able hold out. You may encounter some issues if you winter camp using that kind of energy.
Jan-02-2023 08:05 AM
Jan-02-2023 08:01 AM
Jan-02-2023 04:29 AM
ktmrfs wrote:StirCrazy wrote:
when it comes to power usage, a 12V is not near as energy efficient (battery power wise) as an adsorbition fridge. you will need much more battery capacity and solar or a generator if you switch to 12V compressor.
In terms of BTU or KWH needed to cool, compressor driven fridges are much more efficient than a absorption fridge. Generally you can get about 3x the input BTU used in cooling BTU from a compressor driven fridge. No it doesn't violate any laws of physics, it's the energy needed to move heat from one place to another.
By contrast an absoprtion fridge is much less efficient COP is on the order of 0.7 or less vs 3 or more for compressor fridges.
But in terms of how the energy is stored to use the fridge, propane in BTU/gallon or BTU/weight or BTU/volume FAR FAR FAR exceeds any battery for the same volume or weight.