Norcold not so cold after all

[Studiovette]

I brought my rig home tonight to prepare for a long trip fri morn.
Switched the fridge from off to auto and heard the click click click. Propane was off, and I then plugged into power at my house and switched fridge to off for a min to reset it. Next time I should probably plug in first.
After about an hour my freezer is nice and cold. Down to about 35 per the thermometer I have in there. The fridge however was at 70! So I'm assuming these Norcold fridges cool from the top down. Is that right? Why does the fridge take so long? Is this normal? I felt the aluminum blades in the back thinking they would at least be cold to the touch and nothing. Let's see what the temp is in the AM.

[DanNJanice]

Originally Posted by Studiovette

I brought my rig home tonight to prepare for a long trip fri morn.
Switched the fridge from off to auto and heard the click click click. Propane was off, and I then plugged into power at my house and switched fridge to off for a min to reset it. Next time I should probably plug in first.
After about an hour my freezer is nice and cold. Down to about 35 per the thermometer I have in there. The fridge however was at 70! So I'm assuming these Norcold fridges cool from the top down. Is that right? Why does the fridge take so long? Is this normal? I felt the aluminum blades in the back thinking they would at least be cold to the touch and nothing. Let's see what the temp is in the AM.

If you examine your fridge in the house you will notice it has a fan, to help it cool (among other things). Gas/Propane fridges used in RVs normally do not have that. One hour is not nearly long enough to get the whole thing cool. Go to bed and check it in the morning.

[apgambino]

That's par for the course. I have the 2118 polarmax in my 355w and I find it will take a long time to cool, from the top down, on AC. Propane is a bit faster. To assist it, I have about 6 big ice packs I keep in the garage freezer that I place inside it to kick start it, especially if it is hot out. Once it's up and going I jeep them in the freezer throughout the trip to help it maintain temp, especially on short trips.

2017 Siesmic Wave 355w towed by 2015 Ram 3500

[2nOZ]

We plug ours in the night before our trip or early in the morning if we are planning to leave in the evening. It does take a while to cool down on electric but a bit faster on propane. The hot days make it slow.

[ttavasc]

Originally Posted by Studiovette

I brought my rig home tonight to prepare for a long trip fri morn.
Switched the fridge from off to auto and heard the click click click. Propane was off, and I then plugged into power at my house and switched fridge to off for a min to reset it. Next time I should probably plug in first.
After about an hour my freezer is nice and cold. Down to about 35 per the thermometer I have in there. The fridge however was at 70! So I'm assuming these Norcold fridges cool from the top down. Is that right? Why does the fridge take so long? Is this normal? I felt the aluminum blades in the back thinking they would at least be cold to the touch and nothing. Let's see what the temp is in the AM.

Under normal operation you should feel some heat coming off the condenser fins in the back. Excessive heat build-up can cause degraded performance so you want to make sure there is good air flow from the bottom where the boiler unit is up through the condenser coil/fins at the top and either out the side or top exhaust vent. You can improve performance by installing a vent fan with a thermistor on it to help the air flow across the condenser fins. I did that and there was a noticeable improvement in cool-down time and overall performance.

If you are interested here is a decent explanation of how the absorption fridges work:

The RV Doctor: RV Absorption Refrigeration Basics

[Studiovette]

Originally Posted by ttavasc

Under normal operation you should feel some heat coming off the condenser fins in the back. Excessive heat build-up can cause degraded performance so you want to make sure there is good air flow from the bottom where the boiler unit is up through the condenser coil/fins at the top and either out the side or top exhaust vent. You can improve performance by installing a vent fan with a thermistor on it to help the air flow across the condenser fins. I did that and there was a noticeable improvement in cool-down time and overall performance.

If you are interested here is a decent explanation of how the absorption fridges work:

The RV Doctor: RV Absorption Refrigeration Basics

Thanks will read this. I would definitely like more info on the fan mod.

[Studiovette]

Now that's cold! [emoji1]

Sent from my LGLS991 using Tapatalk

[norty1]

The absorption technology we use in rv's, prior to residential fridge's lately is just one step up from the ice box that was used when I was a child. You put a block of ice in the top and the cold air would fall down and cool the bottom. The closer to the ice, the colder the fridge was.

The absorption theory listed in the RV Doctor article describes how they just replace the ice with a unit that circulated ammonia to keep the top cold. It uses the same theory on gas or electric because that is just the heat source for keeping the Ammonia process working The cold in the bottom is still accomplished by cold air at the top falling down to the bottom.

It takes time and every time the door is opened, it starts over. A small fan inside can help keep the bottom area cooler faster.

[ttavasc]

Originally Posted by Studiovette

Thanks will read this. I would definitely like more info on the fan mod.

This is the vent fan that I installed:

FridgeCool Exhaust Fan, 12-Volt, Carded - Valterra.com | Valterra.com

I had to shorten the barrel housing the fan is mounted in to fit it in - not much room around the back in my small unit. As I recall the thermistor is set to start the fan at 100 degrees and shut it off when it is back down to 80. I mounted mine in in the exhaust vent area just above the condenser.

[Studiovette]

Thanks. So this requires pulling the fridge out etc.. I think I saw where some people just use a battery operated fan inside the fridge obv it's prob not the same result but not sure I'm capable of doing this type of install. My bro however is a certified HVAC and refrigeration mech so maybe I'll have him help!!

Sent from my LGLS991 using Tapatalk

[ttavasc]

No need to pull the fridge out - you can install it just by removing one of the external vent covers on the side of the trailer. Here are a couple pictures of my install. I just threaded the wires into the cupboard beside the fridge and attached a 12v lighter-style adapter to plug into the outlet on the wall above the counter as my unit was still under warranty and I didn't want to mess with the hard wiring. At some point I'll hardwire it in....

The fans that go inside the fridge are intended to more evenly and effectively distribute the air as it's cooled. Given how small our fridge is I have not felt the need to use one of those.

[bdreinv]

We have the 12 cu.ft. Norcold and are in Phoenix, AZ.Usually turn ac on in the evening turn frig on. Fill it full of cold beer pop ect.And then put 10 lb. bag of ice in freezer.Works good.Have read where some folks line the door shelves with bubble wrap.

[Studiovette]

Originally Posted by ttavasc

No need to pull the fridge out - you can install it just by removing one of the external vent covers on the side of the trailer. Here are a couple pictures of my install. I just threaded the wires into the cupboard beside the fridge and attached a 12v lighter-style adapter to plug into the outlet on the wall above the counter as my unit was still under warranty and I didn't want to mess with the hard wiring. At some point I'll hardwire it in....

The fans that go inside the fridge are intended to more evenly and effectively distribute the air as it's cooled. Given how small our fridge is I have not felt the need to use one of those.

Awesome. Might have to try this.

[CoCanCarv]

I have a small Norcold and use four frozen used juice bottles. I can cool the fridge in a 1/4 of the time. I will buy a small fan next.

Originally Posted by apgambino

That's par for the course. I have the 2118 polarmax in my 355w and I find it will take a long time to cool, from the top down, on AC. Propane is a bit faster. To assist it, I have about 6 big ice packs I keep in the garage freezer that I place inside it to kick start it, especially if it is hot out. Once it's up and going I jeep them in the freezer throughout the trip to help it maintain temp, especially on short trips.

2017 Siesmic Wave 355w towed by 2015 Ram 3500

[poohbear]

They actually cool off faster with stuff needing to cool loaded up as the heat transfer speeds the absorption process.
The condenser fan can be installed by removing the roof vent cap & mounting inside the vent feeding the wires down .