Refer Vent Blockage

[2000_Kiwi]

Ok, so I know there have been hundreds of vent fan installations posted here... But even if you don't plan on, or don't want to install a vent fan, you may want to check for airflow obstructions.

I know the southeastern summer is going to be a hot one and I wanted to make sure my refrigerator is running as efficiently as possible.

I went to install a vent fan, when I pulled off the roof vent cover I noticed the rubber roof was blocking much of the airflow.



So... I cut back the rubber roof a few inches... To my amazement I found that the wall insulation on both sides had fallen over on to the refrigerator fins. In the photo below I had already cleared the insulation from the right side.



In short, you may want to check for any obstructions that may limit the airflow behind your refrigerator.

Power was easy to locate...





Vent cover sealed with Eternabond tape.


Fan installation looking from the roof vent down behind the refrigerator.


Fan installation looking from the bottom vent up to the roof vent behind the refrigerator.


Unfortunately I don't have any before and after airflow or temperature specs but I know just removing the obstructions will be an improvement!

[2000_Kiwi]

Gjac wrote:

2000_Kiwi wrote:

machunt wrote:
how are the vent caps removed?

Mine had four screws securing the cover. I had to cut the screen to gain access to mount the fan.

The screen on mine was held on with screws also but were not visible under the caulking. Once you remove the caulking the screws are visible and can be removed without cutting the screen.

With my roof vent there were only screws for the cover. If I wanted to remove the screen without cutting it I would have had to remove the Dicor sealer and break the seal between the vent and rubber roof. I opted to cut and seal just the screen. I already had the eternabond tape so it made it easy. Time will tell how well it holds up.

Cut Screen


Screen sealed with eternabond tape.

[Gjac]

2000_Kiwi wrote:

machunt wrote:
how are the vent caps removed?

Mine had four screws securing the cover. I had to cut the screen to gain access to mount the fan.

The screen on mine was held on with screws also but were not visible under the caulking. Once you remove the caulking the screws are visible and can be removed without cutting the screen.

[Tango__AE7UI]

I installed 3 fans in the reefer stack; I had them on hand so I used them at the top of the stack.
Wired to an on/off switch inside the fifth.
Some fan noise is noticeable but with the radios on (ham and marine band monitoring) I really don't notice them.
Current draw is low and the 280 watts of solar keeps the batteries charged.

[2000_Kiwi]

When the fan does come on, I don't notice any draft or movement of air at the roof vent. I wonder if I should install a baffle around the fan so it operate more efficiently. My concern would be that adding the baffle would restrict airflow when the fan was not running...

[2000_Kiwi]

PA hide away wrote:
This is the exact situation that cost by brother in-law a new refrigerator.
The factory installed unit failed after 6 years of very little use. The unit exhibited all the signs of overheating failure including sudden loss of coolant through a stress cracked boiler. When we pulled out the refrigerator we discovered that insulation had come loose and completely covered the cooling coils. This trailer came directly from the manufacturer to the campground and never moved again. I believe that many of these premature refrigerator failures have this same cause, poor quality control at the factory.

I am glad I caught it before it stopped working!

[2000_Kiwi]

machunt wrote:
how are the vent caps removed?

Mine had four screws securing the cover. I had to cut the screen to gain access to mount the fan.

[machunt]

how are the vent caps removed?

[PA_hide_away]

This is the exact situation that cost by brother in-law a new refrigerator.
The factory installed unit failed after 6 years of very little use. The unit exhibited all the signs of overheating failure including sudden loss of coolant through a stress cracked boiler. When we pulled out the refrigerator we discovered that insulation had come loose and completely covered the cooling coils. This trailer came directly from the manufacturer to the campground and never moved again. I believe that many of these premature refrigerator failures have this same cause, poor quality control at the factory.

[nineoaks2004]

I have found birds nests in the vent before, any obstruction will surely affect the reefer

[ScottG]

It's kind of a wonder it worked as well as it did!
I bet a lot of RV's could use this kind of fix.

[Blue_Hill]

Wow. Thanks for posting this. I'll be checking this as soon as I get the trailer out of storage. My trailer came with a vent fan in the exhaust stack and it always seemed to me that the fan runs quite a bit. This can be a significant power draw when boondocking, but I thought it must have to be that way. I never thought of looking down the stack to check for blockages.

[ScottG]

Nice work.
Mine was in a similar condition especially the roof vent.
After fine tuning my installation it can be well into tripple digits and has no problem working on electric.