Journey with Confidence RV GPS App RV Trip Planner RV LIFE Campground Reviews RV Maintenance Take a Speed Test Free 7 Day Trial ×
Jayco RV Owners Forum
 


Reply
 
Thread Tools Search this Thread Display Modes
 
Old 07-18-2020, 02:43 PM   #21
Senior Member
 
Rock's Avatar
 
Join Date: Sep 2015
Location: Mexico Beach
Posts: 2,196
I added one to the topside plastic access panel. Zip tied inside panel to give more flow. Also added the three fan unit with leds inside the fridge. That is held to the inside fins with clips. Ran power wire thru fridge drain hose and out of end of hose behind fridge for power. The inside fridge fan really made a difference. When fridge is full you have to many hot spots.
Attached Thumbnails
06377DA6-14AC-4809-8ECA-947BF9C2F808.jpg  
__________________
2024 Greyhawk 30Z
2023 Jeep Gladiator High Altitude Toad
2019 Ram 3500. Traded
2016 Pinnacle FBTS Traded
Rock is offline   Reply With Quote
Old 07-31-2020, 10:32 PM   #22
Senior Member
 
Join Date: Jan 2020
Location: Wyoming
Posts: 417
A theory question: Is it possible to get the pipes on these gas absorption refrigerators too cool to the point where the interior refrigerator/freezer won't cool properly?

I installed cooling fans for my Norcold N305. The kit comes with a thermostatic switch but I'm not currently using it. The cooling is so poor on my N305 that I figured running the 140mm fans full bore to provide as much air circulation and compartment cooling as possible would work best.
Click image for larger version

Name:	20200710_154719.jpg
Views:	4
Size:	89.7 KB
ID:	61948

Performance was still pretty terrible as outside temps climbed into the high 90s. I even switched to 120v electric with the (incorrect?) theory that the electric mechanism would produce less heat than the gas mechanism and therefore allow the refrigerator to cool more efficiently.

Then I started reading about people who switch from electric to gas to get more efficient cooling. Seems counterintuitive, but these are, after all, gas absorption systems that rely on heat for their function.

I also read the gas absorption FAQs on Norcold's website where it seems to indicate thermostatic control of vent fans is important. (Perhaps to prevent overcooling of the pipes?)
Click image for larger version

Name:	Refrigerator Fan Temps.jpg
Views:	6
Size:	69.0 KB
ID:	61949

How do these things work? Is cooling good but only to a point? Does overcooling (with vent fans) interfere with the gas absorption cycle?
Bob K is offline   Reply With Quote
Old 08-01-2020, 10:21 AM   #23
Senior Member
 
Join Date: Jun 2016
Location: Denver
Posts: 4,248
Interesting. On at 95*F off at 80...
__________________
2016 Greyhawk 31FK
pconroy is offline   Reply With Quote
Old 08-01-2020, 11:14 AM   #24
Senior Member
 
JimD's Avatar
 
Join Date: Apr 2017
Location: Inland Empire, California
Posts: 2,005
Quote:
Originally Posted by Bob K View Post
A theory question: Is it possible to get the pipes on these gas absorption refrigerators too cool to the point where the interior refrigerator/freezer won't cool properly?

Then I started reading about people who switch from electric to gas to get more efficient cooling. Seems counterintuitive, but these are, after all, gas absorption systems that rely on heat for their function.
The reason for thermostat control is to shut down the fans when not needed. If the fridge has reached the set temp and has shut down cooling, the fans are not needed. Also, if the weather is cold enough the heat buildup in back may not warrant the extra air movement.

My unit has 2 fans at the top set to turn on at 130 degrees. My last trip out in 105 degree weather had them running most of the time. I don't remember hearing them previously when it wasn't so hot out.

I don't think you can over cool these things as long as you are not trying to cool the boiler area. The spec for lowest temp that it can operate in is 32 degrees at which point they recommend a low temp kit of some sort.

Here is an article on how these things work.
https://www.rvrepairclub.com/article...ration-works/#

Looks like the liquid is heated by the boiler and then cools and runs down the tubing in back where it cools down. I would guess it works better when the liquid cools down more (up to a point) which is why these things don't work as well when it is hot outside.

As far as gas versus electric, I think (no real facts) that gas works better. Last time I was at a campground in heat their voltage coming in was only 105 volts whcih is the low spec for my unit. I switched over to gas.
__________________


Jim

Retired electronic technician (45 years in the field)
2017 Greyhawk 29W (solar & many other mods)
wife (maybe I should have given her top billing)
JimD is offline   Reply With Quote
Old 08-01-2020, 12:07 PM   #25
Senior Member
 
Join Date: Jan 2020
Location: Wyoming
Posts: 417
Quote:
Originally Posted by JimD View Post
I don't think you can over cool these things as long as you are not trying to cool the boiler area. The spec for lowest temp that it can operate in is 32 degrees at which point they recommend a low temp kit of some sort.

Here is an article on how these things work.
https://www.rvrepairclub.com/article...ration-works/#
I'm leaning toward the same conclusion after watching some "YouTubes".



Quote:
Looks like the liquid is heated by the boiler and then cools and runs down the tubing in back where it cools down. I would guess it works better when the liquid cools down more (up to a point) which is why these things don't work as well when it is hot outside.
And since the boiling point of pure ammonia is -28F at STP (not the case in a sealed fridge mixed with other chemicals, but a good generality to reference), that's a lot lower than any normal ambient TT temp.

Quote:
As far as gas versus electric, I think (no real facts) that gas works better. Last time I was at a campground in heat their voltage coming in was only 105 volts whcih is the low spec for my unit. I switched over to gas.
I'm going to keep this as a test in the future.
Bob K is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


» Featured Campgrounds

Reviews provided by

Powered by vBadvanced CMPS v3.2.3
Disclaimer:

This website is not affiliated with or endorsed by Jayco, Inc. or any of its affiliates. This is an independent, unofficial site.


All times are GMT -6. The time now is 01:57 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Copyright 2002-2016 Social Knowledge, LLC All Rights Reserved.