Conversion to residential refrigerator. Venting?

[mlh2013]

Originally Posted by rrthor

Just wanted to report back on my new refrigerator install. I have installed and removed the unit three times now due to having to make small adjustments. It was a very tight fit trying to get all the clearance requirements for the fridge and the furnace.

I did close up the space to eliminate any venting to the outside. I used some fiberglass insulation and a Luan panel for the top vent. For the bottom vent I made an insulated panel that can be removed and installed with the refrigerator in place. I needed this in order to get to the brackets that bolt the rear of the fridge to the floor. It also allows access to the compressor compartment.

The clearance required for the top of the fridge is 2” and I am a little shy of that at 1 7/8”. I have 13/16” clearance on the sides and 4” on the back. Notice in the picture how close the top of the right-hand door is to the rail for my pocket door.

Again, thanks for all the responses. Next project is to fabricate a refrigerator door and drawer lock.

Looks great

[cocolaboy]

Originally Posted by rrthor

i am installing a residential refrigerator as a replacement for an absorption unit. I was hoping i might get some feedback on my plans for ventilating the cabinet. I am just about ready to install the new fridge. I have attached four pictures.

One picture shows the whole cabinet. The insulation you see around the perimeter of the opening is to keep cold or hot air from coming inside the coach.

There are two pictures, one showing the lower vent and the other is the ceiling vent. I am thinking natural convection will cause air to intake from the bottom and will exhaust out the vent in the ceiling.

The other picture is of the refrigerator. This picture shows an opening at the bottom backside of the refrigerator. This is the only opening on the refrigerator. The sides, top and bottom are all solid. I believe the evaporator coil is attached to the inside of the back panel of the fridge. I think this because when i was testing the unit in the garage the back panel would get warm. Also, you can see the plastic tray bolted to the back of the fridge at the top of the opening. This is the condensate tray.

I’d appreciate any thoughts on my plan, especially from folks who have made this conversion before. Thanks in advance.

just wondering about the water from the defrost cycle goes where hope not in the white bucket because if you move it will go on the floor on mine i put outside drain to make sure because water and rv floor are not friendly

[Johnynorthla]

Originally Posted by John Kaehms

As I was reading the comments on converting from an RV refrigerator to a residential refrigerator I did not see any discussion about the type of refrigerant used in the residential refrigerator.

Newer model residential refrigerators often use a highly flammable refrigerant such as cyclopentane. Units such as Magic Chef have a warning sticker on the back of their units that warns about proper space around the unit for venting. Pay attention to the owners manual regarding venting and space requirements.

I looked at this issue when we changed our Norcold 1200 series unit to one from JC Refrigeration. The JC cooling unit uses non flammable R134a refrigerant. Also, some, if not most, residential refrigerators are constructed of light weight materials that are not intended for the rigors of a rolling earthquake.

Stay safe out there,
JK

Cyclopentane is a blowing agent for the polyurethane foams that are used to insulate refrigerators and freezers. Unlike some other chemicals used to insulate refrigerators, cyclopentane does not contain hydro-fluorocarbons (HFCs). Using cyclopentane results in significant reductions in equivalent CO2 emissions.

[rrthor]

Originally Posted by cocolaboy

just wondering about the water from the defrost cycle goes where hope not in the white bucket because if you move it will go on the floor on mine i put outside drain to make sure because water and rv floor are not friendly

The white tray you see in the picture of the compressor has one of the refrigerant lines routed through it. It's hard to see but if you download the picture and zoom in you can see it a bit better. I believe the intent is to evaporate the condensate using a warm refrigerant line. That's only a guess. Maybe a refrigerant expert will chime in.

[Gary RVRoamer]

Residential fridges are designed to work without external ventilation. Nearly all of them draw air from the interior of the room, underneath the fridge, up the back and out into the room again over the top. Some may require side clearance for ventilation as well. Yes, it adds some heat to the interior of the RV, but its not a lot. Welcome in cool weather, but an extra burden on the a/c in mid-summer.


I recommend no external venting, but if you choose to go that way, you need to seal all around the fridge so that cold or hot outside air isn't flowing into the RV interior. Ditto for critters, e.g. bugs, mice, etc. If your fridge in one of the many that has its primary radiator underneath, you may need to add a fan or duct to get adequate air circulation under there.


I sealed off the lower and upper vents when I replaced my Norcold 1200 with a GE residential fridge. Never found the extra interior heat to be a problem.

[FIRE UP]

Originally Posted by Gary RVRoamer

Residential fridges are designed to work without external ventilation. Nearly all of them draw air from the interior of the room, underneath the fridge, up the back and out into the room again over the top. Some may require side clearance for ventilation as well. Yes, it adds some heat to the interior of the RV, but its not a lot. Welcome in cool weather, but an extra burden on the a/c in mid-summer.


I recommend no external venting, but if you choose to go that way, you need to seal all around the fridge so that cold or hot outside air isn't flowing into the RV interior. Ditto for critters, e.g. bugs, mice, etc. If your fridge in one of the many that has its primary radiator underneath, you may need to add a fan or duct to get adequate air circulation under there.


I sealed off the lower and upper vents when I replaced my Norcold 1200 with a GE residential fridge. Never found the extra interior heat to be a problem.

Gary,
Gotta question or two about some of your statement(s). You state that you "recommend no external venting...." Well, I'm no really expert of any type when it comes refrigeration but, as I understand it, the process of cooling inside a fridge is actually the removal of HEAT, correct? And, that heat is now on the OUTSIDE of the inside, meaning it's maybe in between the outside skin and the inside compartment, maybe.

And, that heat needs to go somewhere, or it will just stay trapped in the coil/fins/radiator area, correct? If that area builds up too much heat while the system is removing it from the interior of the fridge, then the efficiency is reduced, correct?

Sooooo, with all that being said, and IF that heat has to be dissipated to somewhere, then if your exterior of your fridge compartment is sealed, then where is that heat supposed to go? I installed a Magic Chef 10.1 cu.ft. fridge a couple of years ago and the business compartment where the compressor etc. lives is directly perfect to the outside compartment access.

When I first fired that new fridge up, yep, it got real cold inside, as expected. But, when I removed the outside compartment cover, that compressor was HOT! So, I Macgyvered an old computer fan to blow not only on that compressor but to hyper circulate that air in that immediate area. That now keeps that compressor down to a low "Warm" instead of HOT. But, my original roof vent is also still open as it always was.

Second,
You state that "..Nearly all of them draw air from the interior of the room, underneath the fridge, up the back and out into the room again over the top." Well, my new Magic Chef, has only one small opening at the rear bottom. If air is drawn into it, by how I would not know because there is no fan that I can see or hear, and then spit out someplace, it can only spit that heated air out the same exact place it potentially drew it in in the first place. And that little heavy business area is primarily sealed from the rest of the fridge, that I can see. So, I can't figure out how that new little fridge actually circulates air, to extract heat from the inside and expel it to the outside.
Scott

[Olyteddy]

..."Newer model residential refrigerators often use a highly flammable refrigerant such as cyclopentane."

Originally Posted by Johnynorthla

Cyclopentane is a blowing agent for the polyurethane foams that are used to insulate refrigerators and freezers.

That is correct. The first one only partially correct (the flammable refrigerant is isobutane aka R600a). Cyclopentane is also very flammable but is only used for expanding the foam insulation. It is supposedly not flammable when the foam cures.

[John Kaehms]

Originally Posted by Johnynorthla

Cyclopentane is a blowing agent for the polyurethane foams that are used to insulate refrigerators and freezers. Unlike some other chemicals used to insulate refrigerators, cyclopentane does not contain hydro-fluorocarbons (HFCs). Using cyclopentane results in significant reductions in equivalent CO2 emissions.

Hi Johnnynorthla,
Yes, your quote from Google is correct word for word. I would suggest that readers do their own search on cyclopentane and read about the flammability of the product when used in foam products and when used as a refrigerant. There is a lot more information on this product than just the quote you cited.
Stay safe,
JK

[BikesAndGuns]

Well, if you have stick & bricks unit, guess you'd better get to work McGyvering the ventilation for your home refrigerator as well!

[DRM901]

I recently went into a house with no heat on, in Michigan. Inside was in the low 40s. And the refrig wasn't working correctly. Both the refrig & freezer were the same temp: 35°. After checking the refrig out and finding nothing wrong, I guessed it was just too cold for it.

Got the room back up to normal living temps. It took about 12 hours, but I finally got the thing working correctly. It did take me cranking the refrig down to the coldest temp, I think to really get the compressor going for a while.

The moral of the story: Don't leave a residential refrig open to the outside of you ever travel in cold weather. Or you may have a similar experience.

Sent from my SM-G973U using iRV2 - RV Forum mobile app

[Bigd9]

Originally Posted by DRM901

I recently went into a house with no heat on, in Michigan. Inside was in the low 40s. And the refrig wasn't working correctly. Both the refrig & freezer were the same temp: 35°. After checking the refrig out and finding nothing wrong, I guessed it was just too cold for it.

Got the room back up to normal living temps. It took about 12 hours, but I finally got the thing working correctly. It did take me cranking the refrig down to the coldest temp, I think to really get the compressor going for a while.

The moral of the story: Don't leave a residential refrig open to the outside of you ever travel in cold weather. Or you may have a similar experience.

Sent from my SM-G973U using iRV2 - RV Forum mobile app

Like I indicated in post #9, a lot of refrigerators only have one thermostat, and its located in the refrigerator compartment, not the freezer compartment. When the refrigerator compartment "sees" 35/37 degrees it shuts off the compressor. HOWEVER, since there is only one thermostat, the freezer compartment also shuts down the cooling. Now if the room temperatures drop down to say 35 degrees, you can see how the refrigerator compartment will achieve its temperature fast and shut down, but the poor freezer will start to warm up since the coolant has stopped flowing.

The freezer compartment does have a adjustable louver to allow either more of less cooling, but its useless if the compressor is not running.

Now they do make "garage" ready refrigerators that handle the cold exterior temperatures, and they even make a kit you can add onto the refrigerator, but they basically warm the compressor oil, and some warm the thermostat tricking it into thinking the refrigerator is warm and keeping the compressor running.

BTW, the refrigerator in my coach is also sitting at 35 degrees, since the room in the motorhome is about the same.

[Dodge Guy]

Residential fridges require inside air for proper operation. Using cold or hot outside air will cause cooling issues.

[Johnynorthla]

We have a new 12V fridge, Will cold temps damage anything?

If your coach sits overnight in cold temps the night before a trip I guess you have to leave your heat on? This is what’s going to happen to us with our new 12V fridge. We are in NE PA until after thanksgiving, then we head south. Rigs parked in my driveway temps are 20’s over night, I guess I’ll be burning up our LP!

[Bigd9]

Originally Posted by Johnynorthla

We have a new 12V fridge, Will cold temps damage anything?

If your coach sits overnight in cold temps the night before a trip I guess you have to leave your heat on? This is what’s going to happen to us with our new 12V fridge. We are in NE PA until after thanksgiving, then we head south. Rigs parked in my driveway temps are 20’s over night, I guess I’ll be burning up our LP!

Things I would wonder about:
What does your owners manual and/or manufacturer specifications for your twelve (12) volt refrigerator indicate is the minimum operational temperatures? Does it have a compressor where oil temperatures are a concern? Does it still have a warranty? What are the details of what the warranty will and will not cover?