65L Isotherm 2-way fridge questions

[abqbw]

I have new (Feb 2017) Hawk front dinette with a Isotherm 65L 2-way compressor refrigerator. Before this I had a Hawk shell model and used an ARB 50qt/47L fridge. The ARB seemed to be much more power efficient and seemed to cool better. I understand that by their very design front loaders are going to loose much more cold air air when you open them than the top loaders. But I am surprised by how much better the ARB performed than the Isotherm.

I am looking for tips on how I can use the isotherm 65L more efficiently and what I can realistically expect. This week it was very hot (high 90s) where I live and I turned the fridge on with a gallon block of ice in it to help it cool down. I ran it all day with just the ice block in it and it never got down to the mid 30 deg F I like to maintain. FWCs manual says the fridge should work at temps up to 113F. Once it was cool enough I loaded it very full with pre-chilled food and it continued to struggle to keep the temps below 40F. It was very hot outside (upper 90s) and about 95F in the camper. I opened and closed the door several times over a couple of hours loading it. My voltage never dropped below 12.5 V (per the zamp solar controller).

My questions:

1. Would it help if I installed an auxiliary fan in the vent space blowing on the compressor coils?

2. Does it hurt performance to "overstuff" the fridge ? I have read the fridge works better when full, but maybe I overdid it and killed all circulation hampering cooling performance...

3. Is this fridge just not capable of keeping the temp in the low 30s when it is in the upper 90s (in a dry desert climate). I try to park with the fridge and vents on the shady side of the camper but often it ends up on the sunny side.

4. When shore power is available will the fridge run better/worse/same on AC power as on 12V? My understanding is that the fridge just converts power to 12v anyway.

5. Is the temp dial a true thermostat? Will turning the temp dial colder than the 4.5 setting I use in cooler weather to maintain low 30s temps make a difference when it is hotter outside?

6. Would it be feasible to install some sort of pull up barrier vertically in the fridge to keep the cold air from spilling out every time the door is opened. Has anyone tried this?

7. Has anyone removed a built in front opening fridge and installed a top opening fridge in its space?
Any fridge tips would be greatly appreciated. I know fridges have been discussed at length on WTW but the search function did not lead me to answers..

Any fridge tips would be greatly appreciated !

Thank you!
Brandon

 

[Timothy McGowen]

I have the 130L version in my 2016 front dinette Hawk.

Loading with pre-cooled food/beverage definitely helps and I believe you probably can overstuff the fridge restricting airflow. How much that is, I'm not sure.

I usually plug mine in the night before (for 12v recharge not on 110v) loaded with the pre-cooled beverages set to 6 or so to get a head start on cooling. I turn it to 4.5 to 5.5 after the first day. I have noticed that this works well.

That being said, I have noticed that after several days, three or four, that the fridge and contents seem to reach a balance that is cooler than the first few days. With temperatures in the 90's it obviously puts more demand on the system and understandably runs more. The temperature also seems to creep up a few degrees as well.

Let me also say that I prefer very cold beverages and that is my measuring stick. The food temperatures remain very safe. Even the ice cream sandwiches in the freezer do OK.

I run this on 12volt only with a 160w solar panel on the roof as factory installed, no auxiliary fan. The nice thing is that usually when the temperatures are so high the sun is also generating lots of power.

Although I have had limited time with temperatures in the 90's so far, while in the 70's and 80's I can usually get mid 30's in the fridge and 4 degrees in the freezer. A $5 thermometer from Walmart really helped me understand what was actually happening.

This is my only experience with an RV refrigerator so take what I say with a squeeze of lime and a grain of salt.

Although my "research" is not complete I can share that storing certain beverages on their side on the rack below the freezer is very advantageous. Also in the 130L model the freezer with hold 7 twelve ounce cans. If the beverage is properly cooled in the fridge portion then given an extra 5-7 minutes in the freezer it comes out just about right, just saying - my research is not complete.

 

[TacoTruck]

I'm missing my ARB fridge also. The FWC salesman to me I would be happy Isotherm fridge. After spending a weekend in 90 plus degree temperatures, fridge running constantly and 160 watt panel never able to fully charge the dual batteries. I can say I'm not happy but willing to accept it. The ARB on a dual battery system could go a day maybe a day and a half with no solar before drawing voltage down to below 12v. I think ARB's are much better insulated.

 

[abqbw]

I have the 130L version in my 2016 front dinette Hawk.

Loading with pre-cooled food/beverage definitely helps and I believe you probably can overstuff the fridge restricting airflow. How much that is, I'm not sure.

I usually plug mine in the night before (for 12v recharge not on 110v) loaded with the pre-cooled beverages set to 6 or so to get a head start on cooling. I turn it to 4.5 to 5.5 after the first day. I have noticed that this works well.

That being said, I have noticed that after several days, three or four, that the fridge and contents seem to reach a balance that is cooler than the first few days. With temperatures in the 90's it obviously puts more demand on the system and understandably runs more. The temperature also seems to creep up a few degrees as well.

Let me also say that I prefer very cold beverages and that is my measuring stick. The food temperatures remain very safe. Even the ice cream sandwiches in the freezer do OK.

I run this on 12volt only with a 160w solar panel on the roof as factory installed, no auxiliary fan. The nice thing is that usually when the temperatures are so high the sun is also generating lots of power.

Although I have had limited time with temperatures in the 90's so far, while in the 70's and 80's I can usually get mid 30's in the fridge and 4 degrees in the freezer. A $5 thermometer from Walmart really helped me understand what was actually happening.

This is my only experience with an RV refrigerator so take what I say with a squeeze of lime and a grain of salt.

Although my "research" is not complete I can share that storing certain beverages on their side on the rack below the freezer is very advantageous. Also in the 130L model the freezer with hold 7 twelve ounce cans. If the beverage is properly cooled in the fridge portion then given an extra 5-7 minutes in the freezer it comes out just about right, just saying - my research is not complete.

Thanks for the good info! My freezer does stay freezing. My ice cream bars stayed frozen pretty hard.

 

[abqbw]

I'm missing my ARB fridge also. The FWC salesman to me I would be happy Isotherm fridge. After spending a weekend in 90 plus degree temperatures, fridge running constantly and 160 watt panel never able to fully charge the dual batteries. I can say I'm not happy but willing to accept it. The ARB on a dual battery system could go a day maybe a day and a half with no solar before drawing voltage down to below 12v. I think ARB's are much better insulated.

I haven't had issues getting the batteries charged (2 ea 75ah AGMs) with the 160 W solar. But so far I think I have driven my truck every day. I'll keep an eye on it when it is solar only for a couple of days...

 

[nikonron]

I still say Four Wheel campers should offer ARB or similar as an option for fridges. Love my ARB and could run 3 days without charging but I now have it on a 150 watt solar panel and a single AGM battery. Ron

 

[badtoytrd]

I switched to my ARB in a Fleet and couldn't be happier. Just sips on the amps

 

[SeatoSea]

I agree with y'all. My isotherm door never shuts tightly, I've added a bunny lock to hold it closed tight. Pre cool everything. But my spouse served vodka tonic one night with ice, so I know I can make a cocktail once in awhile!

 

[abqbw]

After many days monitoring fridge temps I have concluded the isotherm fridge will not maintain below 40f in 95-100 temps.

I did find that two one gallon blocks of ice will last for several days and I can put things like lunch meat and mayo near the ice.

I also discovered that the performance of the fridge is greatly improved if you have it moderately full of pre-cooled items even if you don't ever open the door. I used a wireless thermometer to track temps. I thought having items in the fridge would only be helpful if the door was opened and the cold air spilled out. Charting temps empty and full without opening doors proved me wrong.

BTW- my fridge is the 85L, not the 65L as I originally posted.

Thanks for everyone's comments!

Brandon Wynn
Albuquerque

 

[abqbw]

After much testing my conclusion is that the isotherm fridge will not keep food safe (below 40F) in ambient temperatures above about 95-97 deg. Even when optimizing usage-(pre-cooled food), parking truck with outside vents out of direct sunlight, never opening fridge door. I monitored and recorded the temperature inside the fridge, inside the fridge vent space, and inside the camper for a couple of weeks using wireless thermometers. The fridge doesn't operate anywhere close to specs that are in the isotherm manual.

I am highly disappointed in both Four Wheel Campers' and Isotherm's inability or unwillingness to be honest or even slightly helpful in answering the very simple question of what ambient temperature will the fridge provide safe food cooling. One would think that the between the fridge manufacturer or FWC that installs them by the hundreds someone might know what to expect for performance.

I highly regret relying on published specifications in choosing a fridge for my brand new $26k plus camper. Absolutely unacceptable. Prior to my new Hawk front dinette with the isotherm 2-way 85L I had a Hawk shell model and used an ARB 50L top loader. The ARB blows the doors off the isotherm in terms of performance.

I am more disappointed in FWC and Isotherm than the fridge's performance. Both companies have been completely useless when it comes to technical support. I considered installing an auxiliary fan in the fridge vent space. There is a pair of loose wires in the vent space. I called FWC tech support and after 3 days of trying to just get ahold of them and finally succeeding and sending them pics of the wires they had no idea about what the wires are for. They built the damn camper 4 months ago and installed the wires but don't know anything about them? After one month the haven't answered.

Had I known the issues I was going to have I would have never wasted so much money on a built in fridge. If you plan on using a camper in the summer in the southwest I recommend that you look elsewhere for refrigeration options than what FWC can provide.

 

[Andy Douglass]

So do you have an open ticket with FWC or Isotherm to address the problem?

 

[CamperCamper]

I don't want to sound condescending, but have you checked the seals around the door? Something might be causing the fridge to be unable to achieve the lower temperatures you are looking for. Another possibility might be a temperature switch that is faulty or installed improperly. Perhaps something is stopping the dial from spinning to its' lowest position. Have you listened to the motor? Does it shut off or does it run continuously? It is possible that you have received a defective fridge. It happens!

I have a new 85L Isotherm in a Hawk flat bed. My first trip out (above 90 every day), I set the temperature to the lowest rating, I filled the fridge and freezer and at the last minute decided I wanted to bring some ice cubes along. The freezer was full so I placed them in a zip lock, inside a tupperware container and placed them at the bottom of the fridge. Then I forgot about them and did not use them the first night as planned. When I discovered them 3 days later, they were still frozen (not even sweating). I had many things to discover on that trip so had not even given the fridge a bit of thought. I took them out and finally adjusted the fridge to the proper setting.

I owned a 2014 Hawk slide-in before the flat bed and have spent weeks on end out on isolated beaches in Mexico in absolute hot, direct sunlight. I always had cold beer but the fridge did run an awful lot-took a breather after the sun went down every day. That fridge was the 85L Dometic too! If I wasn't careful, produce would get ruined by too much cold! FWC changed to the Isotherms because they are a better fridge.

As to your complaints against the folks at FWC, I think that is an isolated problem. I would try again if I were you. I have found them to go very far out of their way to solve customer complaints and problems when presented calmly and politely (not insinuating you were not either). Try speaking with the person who answers the phone and tell her of your problems. she will get you to the right person. From my own experience, my life would be a lot simpler if half of the companies I deal with provided half as much customer service as I have experienced from FWC!

Best of luck and please do follow up and let us know how it turns out. This too shall pass and you will be a happy camper again.

 

[abqbw]

To answer a few questions.

The seal is good. I have even rigged up a bungie to make sure fridge door doesn't rattle open and closed while driving.

The thermostat seems good as when it is below 90 ambient fridge reaches a consistent set temp. The fridge simply can't maintain below 40 deg when ambient hits about 97 deg. And that is tested using a wireless thermometer and not opening the fridge door for days.

The compressor is running. All day because it is not making set temp.

I wouldn't say I have an open ticket with FWC. I'd say it is an abandoned ticket. At their request I emailed pictures of the wires in vent space. They were to get back to me and haven't after a few weeks. About all the info FWC could provide is that they put all the fridges on the bench in their warehouse and if they make temp they are considered good. They could not speak to what ambient temps that the fridge is able to provide safe food cooling in the real world. Isotherm could not provide this information either. What I do know from my testing is that performance is significantly below specifications.

I have generally received good and helpful service from FWC in the past. Based on my latest experience, apparently they have out-grown their ability to provide reliable technical assistance.

 

[PaulT]

I have the Dometic 110L compressor in my 2014 Hawk. It has taken me 3 yrs to arrive at a truce with the fridge. I started out with the thermostat near max and it ran most of the time resulting in batteries quite depleted in the morning. Found point down near 6 where fridge stayed cool enough but could rise to 45.
Added portable 100 watt that could be kept in sun because 100 watts was insufficient. Helped but fussy to keep in sun & vulnerable if we left camper during day. Added 160 watt panel to roof rack. Now have mostly happy batteries.

Just completed week & half in Olympic NP. Played with fridge control & monitored with wireless thermometer. Found spot near 4 where fridge turned on at 41F & off at 37F reliably. Surprised that it was a "warmer" setting. Fridge ran significantly less than before. If sunny, extending awning enough to shade fridge vents, helps a lot.

In reports from Stalking Light and others, the fan makes a significant improvement in removing hot ambient air from cabinet around fridge.

There are two blue wires with connectors mounted in fridge compartment for optional fridge fan that terminate near switch panel and have connectors for panel switch that was not supplied but can be purchased from FWC. Must mount fan in top vent which is non trivial task because awning blocks removing top vent screws.

All in all, this "learning experience" is making headway to making me a happier camper. Just didn't worry about fridge temp or battery state much on this trip.
Next task is completing back up camera mounting.
Paul

 

[abqbw]

I have the Dometic 110L compressor in my 2014 Hawk. It has taken me 3 yrs to arrive at a truce with the fridge. I started out with the thermostat near max and it ran most of the time resulting in batteries quite depleted in the morning. Found point down near 6 where fridge stayed cool enough but could rise to 45.
Added portable 100 watt that could be kept in sun because 100 watts was insufficient. Helped but fussy to keep in sun & vulnerable if we left camper during day. Added 160 watt panel to roof rack. Now have mostly happy batteries.

Just completed week & half in Olympic NP. Played with fridge control & monitored with wireless thermometer. Found spot near 4 where fridge turned on at 41F & off at 37F reliably. Surprised that it was a "warmer" setting. Fridge ran significantly less than before. If sunny, extending awning enough to shade fridge vents, helps a lot.

In reports from Stalking Light and others, the fan makes a significant improvement in removing hot ambient air from cabinet around fridge.

There are two blue wires with connectors mounted in fridge compartment for optional fridge fan that terminate near switch panel and have connectors for panel switch that was not supplied but can be purchased from FWC. Must mount fan in top vent which is non trivial task because awning blocks removing top vent screws.

All in all, this "learning experience" is making headway to making me a happier camper. Just didn't worry about fridge temp or battery state much on this trip.
Next task is completing back up camera mounting.
Paul

Thanks for explaining the loose wires. Surprised that FWC couldn't explain them a couple of months after they manufactured the camper. I found the two blue in the vent space but could only find a blue and a black in the battery box. They were bundled a cable tied with a bunch of other wires. I didn't want to cut the bundle loose on a search and (in my case) destroy mission to find out if the other blue wire was bundled in there so I called FWC for insight. Not a clue and no follow up.

What fan did you use-if you installed one?

 

[Spitfire]

PaulT,

Interesting that the 110L Dometic runs better on a setting of 4. I have one too and I usually run it between 6 and 7 like you did. Is it exactly 4 or a little above or below?

 

[PaulT]

What fan did you use-if you installed one?

I have several fans pulled from computer or other electronics equipment over the years for trial. Not sure which one will be best & want to be able to exchange as needed. They are 12 volt fans that typically pull .15 to .5 amps. I can install with VHB tape permanently but want to be able to replace easily until I think I have the right one. With the fridge on passenger side, the Fiamma awning blocks access to the upper screws holding on the vent to the camper. Removing the awning requires drilling out the 5 pop rivets with one hand while holding the 40 lb awning up and balanced overhead with one hand. So, I have been biding my time until I get some help with disassembly. It hasn't been the highest priority yet but all the parts are on hand.

Interesting that the 110L Dometic runs better on a setting of 4. I have one too and I usually run it between 6 and 7 like you did. Is it exactly 4 or a little above or below?

It is just a little above 4. Start there and monitor temp for several cycles for the cut in/cut out temps and adjust up or down until you get the temp range you want. I don't think the controls on these fridges could remotely be called precise and there may be significant differences between different units. When you are happy with the range of temps, mark the dial with a fine Sharpie so you can get close the next time you camp unless you leave the fridge running all the time as some here do.

Paul

 

[Vic Harder]

Paul, Regarding placement of a second fan, I think your Isotherm fridge is build like my TruckFridge, with the compressor and cooling fins in the top right rear of the fridge (looking at it from the front where the beer goes).

If so, you might want to think about putting your second fan inside the camper like I did. That way the stock fridge and second fan create a huge draft over the condenser coils.

You can see the fan I added in the pic below. It is a big 12v fan that I wired into the stock fridge's harness so it comes on with the stock fan.

Vic

 

[PokyBro]

These are some questions to Vic, in relation to the above response, but anyone is welcome to provide insights.

I am installing an Isotherm 130, 12 volt D.C. Fridge, and I'm trying to get my venting right the first time. I have an upper and lower exterior vent the width of the fridge, from another camper with a Dometic 3-way fridge. I also found a smaller exterior vent I could use that is about 5" x 12", and would perhaps provide adequate air without overdoing it. I realize many campers utilize the full width venting top and bottom.

So, Vic....

I was curious how you feel your fridge venting has worked out for you over the summer. It sounds like adding the fan shown above was favorable. What is the sound level when your fridge is running? What size vent(s) did you use to bring in exterior air. Too me it doesn't make any sense to have a bottom vent, nothing down there.

Thanks,

Poky

 

[DanoT]

Paul, Regarding placement of a second fan, I think your Isotherm fridge is build like my TruckFridge, with the compressor and cooling fins in the top right rear of the fridge (looking at it from the front where the beer goes).

If so, you might want to think about putting your second fan inside the camper like I did. That way the stock fridge and second fan create a huge draft over the condenser coils.

You can see the fan I added in the pic below. It is a big 12v fan that I wired into the stock fridge's harness so it comes on with the stock fan.

Vic

Vic, your auxiliary fan is mounted on what is essentially an outside wall, so I suggest that if you plan to do any cold weather camping that you install a separate on/off switch for the aux fan as well as a cover for the fan.

I mostly do winter camping in ski area parking lots, so I have insulated the "outside walls" on either side of the back of my built in fridge.