Proper use of TM refrigerator fan with compressor refrigerator

funpilot · 05-19-2015, 03:14 PM

A few of us have installed a compressor refrigerator that does not use propane. Any advice when/how we should use the fan we have for the old refrigerator for the compressor model?

**ShrimpBurrito** · 05-19-2015, 05:57 PM

It would seem the use of the fan would be unchanged, at least presuming the coils to your fridge are on the back of the unit. The purpose of the fan is to remove heat from behind the fridge. If the coils are on the bottom of your unit, then perhaps you'd want to remove the slinky that is usually installed atop the fan behind the fridge, so that the hot air will be immediately adjacent to the fan intake.

In any event, the idea is to get heat out of that area. At the very least, so should improve efficiency.

Dave

**rickst29** · 05-19-2015, 10:36 PM

Depends which Dometic. My CR-1110, the biggest one which can fit, has the radiator coils and a small built-in fan mounted at the rear top of the unit. For in-camp use (shells up), I installed a larger, more quiet 'exhaust' fan (140mm) on one side of the upper vent. (The side closer to TM hitch.) I blocked the remaining area of fins with heatproof "flex duct tape", UL-181B. Don't' use normal "Duct Tape", it won't hold.

This fan runs as exhaust, reversing the mode of the original TM fan at the bottom: When the upper fan is connected and running, the lower fan needs to be turned OFF -so that the gaps between its fins become an intake path. But with shells down, driving down the road, the upper vent is completely blocked - so I still use the TM fan (reversed to become an 'intake' fan). I cut off the slinky "clothes dryer vent" quite low, because the back of the fridge doesn't leave enough room for the slinky to fit uncompressed. But you need a little bit of "slinky", or a short segment of 4" aluminimum duct, to keep water from being sucked into the compartment from wet road conditions.

funpilot · 05-20-2015, 06:03 AM

Quote:

Originally Posted by rickst29

Depends which Dometic. My 1110, the biggest one which can fit, has the radiator coils and a small built-in fan mounted at the rear top of the unit. So: For camping, I installed a pair of larger, quiet 'exhaust' fans on the two halves of the upper vent (and I blocked the remaining area of fins with tape. In camp, that cooling scheme works great, and can't be heard. The TM fan turned off, becomes a mere input vent for the upper fans.

But with shells down, the upper vent is completely blocked - so I use the TM fan (still installed as an 'exhaust' fan, reversing the direction of air flow) while driving down the road. I cut off the slinky "clothes dryer vent" quite low, because the back of the fridge doesn't leave enough room for the slinky to fit uncompressed. (Most of the larger size comes from greater depth, in comparison to the 3-way).

I have the same refrigerator. Since I did not install it, I do not know what they did. Is there any easy way for me to install the pair of fans you did without removing the refrigerator?

**rickst29** · 05-21-2015, 08:07 PM

There are a few sources of 12v power and ground at the height you need; an excellent choice is a splice into the 12v "+" and "neutral" connections which go into the Winegard 12V "car socket" plate. (Of course, be sure to pull the corresponding fuse at the DC fuse panel before making wiring changes.) A small "clamp down" connector can be used to make those splices.

The other end of that wire pair should be a connect/disconnect device for the pair of wires. I used computer hard drive connectors (AMP MATE-N-LOK 1-480424-0 Power Connector) with sufficient wire length to reach the fan leads (from the male end) and into the clamp connectors (from the female end). The traditional wiring of those computer connectors is +12V "Yellow", Ground "Black". But TM wiring is +12V Black, Ground White- so a tiny bit of white electric tape might be used to "re-characterize" the black wires from the hard drive connectors.

The power consumption is so small that a thermostat/PID "switch" isn't necessary - just push the ends together at camp, pull them apart for travel and home.

davlin · 07-21-2015, 07:25 AM

Quote:

Originally Posted by rickst29

Depends which Dometic. My CR-1110, the biggest one which can fit, has the radiator coils and a small built-in fan mounted at the rear top of the unit. For in-camp use (shells up), I installed a larger, more quiet 'exhaust' fan (140mm) on one side of the upper vent. (The side closer to TM hitch.) I blocked the remaining area of fins with heatproof "flex duct tape", UL-181B. Don't' use normal "Duct Tape", it won't hold.

This fan runs as exhaust, reversing the mode of the original TM fan at the bottom: When the upper fan is connected and running, the lower fan needs to be turned OFF -so that the gaps between its fins become an intake path. But with shells down, driving down the road, the upper vent is completely blocked - so I still use the TM fan (reversed to become an 'intake' fan). I cut off the slinky "clothes dryer vent" quite low, because the back of the fridge doesn't leave enough room for the slinky to fit uncompressed. But you need a little bit of "slinky", or a short segment of 4" aluminimum duct, to keep water from being sucked into the compartment from wet road conditions.

Rickst29,

Any chance I could get you to post pic's of the back of your CR-1110 install? The view through both the top and bottom vent covers would be useful.

Dave

**rickst29** · 08-24-2015, 02:47 PM

See this Thread (picture and long-winded explanation): http://www.trailmanorowners.com/foru...ad.php?t=16554

I'm using just one fan as describe there. (Leaving a small space for the Dometic fan to blow outwards if my "add-on" fan ever stops running while the Fridge is "on". With that fan and upper vent "blocking" with fancy duct tape (UL-181-B, I don't need the TM-OEM lower fan at all. (Not even in towing). Until today, I had it sitting there with reversed leads for towing - but I just pulled it out completely, leaving nothing but the screen behind.