Dear Dave,
My freezer freezes pretty well all year long. However, my absorption refrigerator has trouble staying below 38 degrees in the hot summer in Arizona. I have installed a computer fan in the outside access, forcing the air upward. Also, I raised the vent cover about 3/4 inch to allow the air to escape better. I have started to investigate putting in an additional domestic refrigerator but have been told that it will not operate very well running through the inverter system in an RV. Dave, any help or advice that you can give me would be appreciated. Thank you. —Gary, 1998 Fleetwood American Dream
Dear Gary,
If the outside temperature is over 100 degrees, like it can be in Arizona, 38 degrees might be the best you can get! There are several RVers out there that would love to have 38 degrees, considering it is only 6 degrees above freezing. I know most of us like to keep beverages in the refrigerator at 34-36, but it’s best to try to keep it below 40. There are a few things you can try, assuming you might be getting some spikes over 40.
First, the computer fan mounted to the base of the outside vent will not do much good, as you have found, as there is too much obstruction with the burner vessel and tubes of the cooling unit. I would try using the 5” fans mounted to the top part of the evaporator tubes that will help pull the majority of the heat out, as the process starts in the freezer. This does require removing the refrigerator and installing the dual fans on the evaporator coil. However, Valterra makes an aftermarket fan that is installed in the roof vent opening and it has gotten very good reviews on Amazon and etrailer.com. You can find it here.
You can also shade the side of the rig the refrigerator is on with an window awning or even a small tarp or pop-up tent. This will cool the sidewall and cavity down, sometimes as much as 20 degrees! And the cooler you can keep the ambient inside temperature the better, pull down the shades and black out curtain and limit the amount of times opening the door.
Residential option?
If you are plugged in all the time, a residential 120-volt refrigerator is a good option. If it runs through the inverter, most have a pass-through feature that allows the 120 volt to pass directly through the inverter to the refrigerator. The only time the inverter is working is if you are boondocking and using house battery power to invert to 120-volt power. In that case, the residential refrigerator will drain your batteries almost overnight, as not only does the refrigerator draw power, so does the inverter.
12-volt compressor-driven fridge might be better
It would be better to replace it with a 12-volt compressor-driven model like Everchill, Dometic, or Norcold. Mike Sokol did a test and found the residential refrigerator going through an inverter only got 10-12 hours with a 100 AH lithium battery while the Dometic 12-volt model lasted 39 hours!
Again, if you are connected to 120-volt power most of the time, a residential refrigerator is fine and typically a little cheaper. The best option depends on how you are hooked up.
You might also enjoy this from Dave
How can I add an inverter to power my refrigerator on 120-volt while on the road?
Read the letter and Dave’s answer.
Dave Solberg is a leading expert in the RV industry and the author of the “RV Handbook.”
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I replaced my broken Dometic absorption fridge with a Norcold N2175 which was an exact fit… I’ve run it a week with zero sunshine off my 5200 WH of battery (2 x 206AH 12V Lithium), and still had 40% battery capacity left. Totally happy.
I installed a Camco fan and solar panel in the chimney of our camper. really worked well. Fan came on with the sunlight and ran until dark( the solar part) had no switches or thermostat. I think it was well worth the money. Easy installation!
Our Norcold easily cools to 37 degrees with a small fridge fan pointed at the fins. The temp setting is set just 2 clicks lower than max.
When our 10 year old RVfridge died (it was 106 in Houston that day) we were desperate to find a replacement. No RV fridges anywhere we called in or near Houston. So wifey found a perfectly fitting 120v fridge at Lowe’s. $450 instead of $1000-1500 or more. Our mobile tech hauled the old one away and installed the new one. We have a travel trailer. This fridge has been wonderful. The beer is ice cold and the ice cubes don’t stick to each other. It’s a lot bigger inside too, so we can put more stuff in it. When we’re on the move I run it off our inverter which runs off two 100ah lithium batteries. The solar on the roof easily keeps the batteries charged. I’m actually glad this happened now.
Really need to check that the flue is completely clear especially just above the flame level. Carbon buildup in the flue can cause a big drop in performance. Easy fix is a long pipe cleaner wire run down from the top til it hits the bottom and wiggle it side to side and up and down. You might even see a small poof of carbon powder fall out the bottom which is a good sign.
I did this trick on a neighbor’s fridge and it saved their family fish fry that evening. The temperature was dropping in only 30 minutes.
I suggest you find out whether a residential frig will fit thru the door. If not, they will have to remove the slide to get it in. Also, assuming the frig sits in a slide, consider the effect of the fully loaded weight of the new frig on the slide itself.
I know MANY Monaco owners who have dumped the NotSoCold absorption fridge then installed a variety of residential fridges in their coaches. Not ONE had to remove a slide to install it. Most times it will either go in through the entry door or through an easily removable salon window. Yes, a fully loaded 18 cu/ft fridge will weigh slightly more than a heavy 12 cu/ft absoption fridge because you have 50% more capacity. However, you don’t have to FILL it up full.
I won’t own a coach unless it has a residential fridge. Been over and done with the piece of junk absorption fridges that have destroyed MANY RV in the last 10 years or more. Go through a few RV Salvage yards in this country and see for yourself how many are there because of the absorption fridge.
I agree, been there done that. Replaced a 12 cu ft Not-so-cold with an 18 cu ft residential in an Allegro Bus we used to own. Night and day difference, huge improvement. Went through a dining area window which is a breeze to R&R. The residential was considerably lighter so even loaded the difference was nil.
I installed 2 4” muffin fans in the exhaust stack about 4” below the roof vent cover to draw exhaust heat up the vent pipe. This helped keeping refrigerator temperature well within normal operating temps. These were 120V fans, so the only time they needed to run was when we were stationary, when you’re driving normal thermosiphoning will draw the heat out.