My Newmar 3436 Fridge - 120 Vs. Propane

[obiwancanoli]

Getting ready for an adventure soon, so will soon turn on the fridge to prepare it for use... next step is going shopping for supplies, and got to thinking about an ice cream thread I posted a while back... while I once posed a query regarding the not quite cold enough freezer (soft ice cream), this time, I'm wondering if the fridge cools/freezes better on one or the other...

My service tech recently recommended I run the fridge on propane, and not internal power via the inverter. But, if I'm where I can access full hookups, would that still apply if I can access shore power?

Which might be colder? Which might freeze and hold that temp so that my ice cream is no longer squishy...?

[wa8yxm]

Ok an RV fridge is not all that energy effiencent. Normal power draw (When cooling) on A/C is around 350-450 watts.. A residential fridge of the same size.> Well let me go look at my apartment unit's label. .It says 4.5 amps at 120 volts or what 540 volt-amps.. What the wattage is (V-A*PF) it did not say or I did not see (Will have to do a photo shoot). but that will be less than 540.

The RV fridge V-A=Watts (power factor 1.0 for a resistor) and 360 watts is 3 amps. The "Rule of thumb" is that will suck about 36 amps from your batteries.
A GC2 pair (Single pair of 220 amp hour Six volt batteries) will NOT last 3 hours.

On propane it draws only a few amps and those same batteries will last for closer to 3 DAYS. (Assuming no other load or re-charge)

[dougrainer]

obiwancanoli wrote:
Also, by the way, I learned that stuffing my freezer to the gills was the primary culprit, since it did not allow much air space for cold air to circulate. I had the thing packed full and tight... no wonder... another reason I recently picked up a Dometic Dual Zone 75DZ to accommodate the additional space needed for the frozen goods

USE rectangular ice cream boxes that you can push flat against the back wall of the freezer. This will allow the COLDEST part of the freezer to transfer that cold to the ice cream. Convection air in the freezer is not really a concern like in the bottom refer portion. Doug

[obiwancanoli]

Also, by the way, I learned that stuffing my freezer to the gills was the primary culprit, since it did not allow much air space for cold air to circulate. I had the thing packed full and tight... no wonder... another reason I recently picked up a Dometic Dual Zone 75DZ to accommodate the additional space needed for the frozen goods

[obiwancanoli]

Lwiddis wrote:
IMO propane makes a fridge cooler. Do you use a small battery fan inside the fridge?

Yes, and it's quiet as a church mouse;)

[dougrainer]

obiwancanoli wrote:
Getting ready for an adventure soon, so will soon turn on the fridge to prepare it for use... next step is going shopping for supplies, and got to thinking about an ice cream thread I posted a while back... while I once posed a query regarding the not quite cold enough freezer (soft ice cream), this time, I'm wondering if the fridge cools/freezes better on one or the other...

My service tech recently recommended I run the fridge on propane, and not internal power via the inverter. But, if I'm where I can access full hookups, would that still apply if I can access shore power?

Which might be colder? Which might freeze and hold that temp so that my ice cream is no longer squishy...?

Like your other post I still state your so called Tech does NOT know what he is talking about. Your system is set up from the Newmar Factory with Inverter controlled 120 to the Refer, the Inverter EVEN IF TURNED ON, will go to standby when Shore power is connected or the Genset is running like I told you on your previous post. AS long as the Inverter has fully charged batteries OR you are driving down the road, the Inverter will operate the refer on 120 just as good as LP. Doug

[dougrainer]

Old-Biscuit wrote:
Electric elements and propane flame provide roughly the SAME heating provided both are operating correctly
Propane is a bit quicker at beginning but both work same provided cooling unit functions properly

If cooling unit has any internal obstructions then overall cooling will be affected regardless of heat source

If dry camping/boondocking then best source would be propane vs AC
If on FHU then AC would be better option due to site fee already includes AC
While in transit.....either but AC if running generator for A/C Cooling then AC for fridge

Bingo, The BTU output is identical for LP and 120. BIG OLD wives tale that LP is "better" Than 120. Now, there ARE problems as OLD BIS stated.
1. You are on 120 at a CG that is full and the weather is hot and everybody is running roof AC's. That usually means the 120 LINE voltage will drop and may drop drastically, which will cause the refer to NOT get cold correctly on 120. This is why it is extremely important to have a plug in digital 120 volt meter in the RV to monitor line voltage to the RV. If it drops below 115 volts SWITCH to LP until the line voltage is above 115 volts. Due to this, people think 120 is inferior to LP, but it is the CONDITIONS that are causing the problem.
2. LP pressure is CRITICAL for operation on LP. The LP flame is basically USELESS in the burner flue/chimney. There is a LOT of heat, but it does not do anything. That is why they install a metal Spiral just above the flame to dispurse the heat to the Metal CU tube.
3. To get BEST results on Ice Cream. Purchase the rectangular box type Ice cream and push it against the back wall or the wall where the CU freezer tubes are located. This will yield colder Ice Cream. The operating temp of the Freezer is 0 to 10 degrees. Most residential's will operate in the 0 to -5 degree range. Doug

[Old-Biscuit]

Electric elements and propane flame provide roughly the SAME heating provided both are operating correctly
Propane is a bit quicker at beginning but both work same provided cooling unit functions properly

If cooling unit has any internal obstructions then overall cooling will be affected regardless of heat source

If dry camping/boondocking then best source would be propane vs AC
If on FHU then AC would be better option due to site fee already includes AC
While in transit.....either but AC if running generator for A/C Cooling then AC for fridge

[Lwiddis]

IMO propane makes a fridge cooler. Do you use a small battery fan inside the fridge?

[theoldwizard1]

Sound like you have an "absorption" refrigerator. Heat is your friend and you will get more heat with propane.

Will that amount of heat make enough cold for hard ice cream ? Good question. It has been debated here numerous time. If solidly frozen food is a priority, I would buy a small freezer (3-5 cu ft) 120V freezer or a (small 1-2 cu ft) 12VDC compressor portable freezer. Either way, you out of pocket expense is about 1/2 to the cost so a medium size residential refrigerator.

Bonus with the residential refrigerator is COLD adult beverages !