Community Forums

SargeW · 09-09-2007, 06:37 PM

My Norcold was giving the wife fits last week when we were having our heat wave on the west coast. Temps were 100+ everyday and the refer was having some trouble keeping its cool. Towards the end of the week I camped across the street from a RV repair that happened to be a Norcold service center. It also happend to be on the coast, so by then there were no issues with the refer.

I went over and talked to the tech for a while, and one of the main issues he indicated is that with rigs with the refer in a slide out, there has been nagging issues with cooling in hot weather. Appearently Norcold is working on a fix for this issue, but basically blames it on the MH manufacturer. Norcold contends that for efficient cooling there must be a roof vent to carry away excess heat in the refer compartment.

The tech suggested adding an additional fan at the top of the refer cabnet to push the hot air out of the refer area and not let it build up. The vents used by Winnie are attractive to look at, but most likely not the most efficient operating design. My vents have three rows of vents, that are paralel to the ground, and are "dome" shaped with the top being solid. This means that the heat must build to a certian level before being expelled out of the upper vent.

Norcold did put a fan on top of the coils in the back of the refer cabnet that point upwards. When running it would assist the air flow from the bottom vent to pass through the coils and eventually escape through the top vent.

As a means of assisting the hot air to exit the cabnet, I mounted two 3" computer CPU fans near the top of the refer cabnet pointed outwards at a 45 degree angle. They greatly assist the air flow out of the cabnet area.

BUT, will this be a problem? The fans right now are wired hot, so they are running all the time. They are very low power draw, 0.16 of an Amp, or 160mA max. But is too much air flow a detrement to the cooling of the refer?? The fans say that they move 33 CFM of air. I looked for a fan with a therimister on it, but couldn't find one. Should I look for a thermal switch to put in line with the fans? And if so, what temp should they be kicking on at??

OK guys, what do you think??

SargeW · 09-09-2007, 06:37 PM

My Norcold was giving the wife fits last week when we were having our heat wave on the west coast. Temps were 100+ everyday and the refer was having some trouble keeping its cool. Towards the end of the week I camped across the street from a RV repair that happened to be a Norcold service center. It also happend to be on the coast, so by then there were no issues with the refer.

I went over and talked to the tech for a while, and one of the main issues he indicated is that with rigs with the refer in a slide out, there has been nagging issues with cooling in hot weather. Appearently Norcold is working on a fix for this issue, but basically blames it on the MH manufacturer. Norcold contends that for efficient cooling there must be a roof vent to carry away excess heat in the refer compartment.

The tech suggested adding an additional fan at the top of the refer cabnet to push the hot air out of the refer area and not let it build up. The vents used by Winnie are attractive to look at, but most likely not the most efficient operating design. My vents have three rows of vents, that are paralel to the ground, and are "dome" shaped with the top being solid. This means that the heat must build to a certian level before being expelled out of the upper vent.

Norcold did put a fan on top of the coils in the back of the refer cabnet that point upwards. When running it would assist the air flow from the bottom vent to pass through the coils and eventually escape through the top vent.

As a means of assisting the hot air to exit the cabnet, I mounted two 3" computer CPU fans near the top of the refer cabnet pointed outwards at a 45 degree angle. They greatly assist the air flow out of the cabnet area.

BUT, will this be a problem? The fans right now are wired hot, so they are running all the time. They are very low power draw, 0.16 of an Amp, or 160mA max. But is too much air flow a detrement to the cooling of the refer?? The fans say that they move 33 CFM of air. I looked for a fan with a therimister on it, but couldn't find one. Should I look for a thermal switch to put in line with the fans? And if so, what temp should they be kicking on at??

OK guys, what do you think??

RV Wizard · 09-10-2007, 01:14 AM

This is what is needed and I have tried to get manufactureres to understand this but most won't authorize this addition under warranty. I would wire all the fans into the thermostat that is already in place so when the heat is present they will do their job but in cold weather they are not running and subcooling the condenser which will effect performance. Thanks for posting the modification.

SargeW · 09-10-2007, 05:57 AM

Thanks Mike. Do you have any idea where the thermostat is on a Norcold double door Refer? That would be the ideal situation for me, but I'm not sure where it is at. Hope it doesen't require pulling the refer out......

Argosy · 09-10-2007, 03:52 PM

I used a snap disc. It is a simple single temperature thermostat used in HVAC. The one I used closes at 110 degrees, opens at 90 degrees (3F01-110).

SargeW · 09-10-2007, 03:58 PM

Thanks for the suggestion, but the fans are running on 12 volts. It looks like the swithch is powered on 120 AC. Is that a correct assumption?

Argosy · 09-10-2007, 04:37 PM

You can use a 120v switch for 12v as long as you stay within the current spec, using a 12v switch with 120v will cause problems. My setup has run on 12v for 3 years with no problems.

SargeW · 09-10-2007, 05:43 PM

Well that sounds like the ideal answer then! Does it wire into the leads of the fans between the power leads and the fan, like one lead on each leg, or is it wired into just the "hot" side of the fan, and cuts in and out as necessary?

Argosy · 09-10-2007, 06:19 PM

I ran my power from the main 12v feed of the refrigerator, just loosened the screw and put an 18ga wire in with it. Ran this to one terminal of the snap disc, the hot wire for the two fans comes off the other side. The snap disk is in series with the 2 fans which are in parallel with each other. Mount the snap disk near the top of the refrigerator where it is hotter but out of the air stream of the fans.
I also added another small computer fan inside the refrigerator to circulate air. It is wired to come on any time the main switch is on. The side of the mh the frig is on is in direct sun when parked at home, in 90+ temps it maintains 38 degrees with no problem.

SargeW · 09-11-2007, 12:00 PM

Great info, thanks. Do you get the snap disc on line, or from any local hvac dealer?

Argosy · 09-11-2007, 12:58 PM

I would try locally first. They are about $12-13, weigh about an ounce. Shipping will probably cost almost as much as the snap disk from the small parts I have ordered lately.

"007" · 09-12-2007, 06:11 AM

Heres a LINK to a fix that was done for a DOMEDIC refer but will work for the Norcold. He installed two fans in top vent opening but rain distroyed them and he installed in lower vent opening. The fan and thermister you can see on fan was bought at Radio S for about $15.

If you have the upper vent as in a slide you can install there as long as the weather does not bother fans. As Argosy said power can come from 12v block on refer deck.

SargeW · 09-13-2007, 04:33 AM

Actually I got lucky, my neighbor is an HVAC service man. He had one in his truck and gave it to me. I wired it in, it took about 2 minutes and so far it is working great. Thanks for all your help!

Sarge