Refrigerator Performance - Keeping Cold in the Heat

[nknowland]

The temp is 90 degrees here in Georgia and my refrigerator is only cooling to 40 degrees at the highest setting. (And I am using an insulated cover). Is this normal? Or the start of refrig problems? How do you know when the refrig is starting to fail?

[DeepFrz]

Tell us more about your refrigerator.

[nknowland]

It's an Aldor Barbor (spelling?) -- 12 volt.

[s/v Beth]

There are a lot of factors that come into play. First what is the refrigeration unit? If it is a Danfoss compressor, then what model? Did it use to keep things cooler? If so, you probably just need new refrigerant. But here is the clincher- if it is an old one, (R-12) refrigerant, you probably need to upgrade your compressor and go with a 134a refrigeration. There are no shortcuts- although a lot of people will tell you otherwise. I just did this with my Valiant. I had a HVAC guy guide me along, and it cost me about 800 dollars.

[Minggat]

Originally Posted by s/v Beth

There are a lot of factors that come into play.

There are no shortcuts- although a lot of people will tell you otherwise.

Yes, lot's of factors. But what constitutes a shortcut, I dunno.

Start at the cheap spot.

Is there frost build up? If so, defrost.

Downstream of that, I would be looking at the quality and dessign of the box. Saying you have good sealed lids doesn't say it all. Start with, is there a drain hole at the bottom of the box? If so, it's a contributor. Plug it.

Then I would look at the unit itself. If it's hot (90) the unit has more work to do to overcome a list full of negatives.

[nknowland]

no frost build-up ... just defrosted. the freezer is keeping meat frozen, but in the winter months, the setting of 5 was sufficient. Now the setting is 7; but like I said, the temp outside is HOT. there is no drain hole in the box, and the lid seal looks good. How do you add new refrigerant?

[Caribsailors]

With Minggat...is there frost. If you have frost on the evap in a 90 degree ambient, I'd say your doing alright, not the best, but consider the liquid temp of the refrigerant and then the NRE (net refrigerating effect).

Check to ensure your condenser is clean and you have good air flow for it. It is the lungs of your system.

Lastly you box is critical. My old girl has an ice box with 28 year old deteriorating foam insulation, I have supplemented the voids with poly-foam and can now get 40F in 95f ambient. If you have leaky box you will do more dehumidifying before you get any sensable cooling.

My question is how is it at 85F and lower humidity.

Cheers

[DeepFrz]

First, if its air cooled, you need to ensure that the fans can move the air efficiently. It should be vented both on the air inlet and exhaust. Or, is it water cooled?

There are many many threads on refrigeration here on the forum, perhaps you should read some of them to get an idea of where you need to start.

Perhaps you need to call a refrigeration specialist in to add refrigerant, but that is probably a later step.

[nknowland]

it's air cooled. and the fans are not obstucted. How do you check the liquid temp of the refrigerant? the refigerant was charged in jan 2008. I've searched the other threads, but they tend to be very generic.

[gettinthere]

If the freezer is freezing meat, it sounds like it's working pretty well. Can you freeze ice cream? That's the ultimate test.
Perhaps open more between the freezer & frig (assuming it's a spill over system) to allow more cold into the frig.

Is this the first hot weather you've experienced with this system? Is there condensation on any of the external walls? Sign of wet insulation that needs upgrading.

How bad is 40 degrees anyway for a 12 volt system?

[Ex-Calif]

Originally Posted by nknowland

no frost build-up ... just defrosted. the freezer is keeping meat frozen, but in the winter months, the setting of 5 was sufficient. Now the setting is 7; but like I said, the temp outside is HOT. there is no drain hole in the box, and the lid seal looks good. How do you add new refrigerant?

If it is a common system and the freezer is frozen and the fridge is warm I would look for door leaks or insulation breakdown - albeit the freezer space is probably a lot smaller than the fridge.

In your warm humid environment I would be looking for any condensation on or around the box.

Baring that you probably need to pressure test the refrigerant system and possibly resort to some of the solutions above.

[MarkJ]

Lots of boats have hugh fridges!

We put a sealed foam beer cooling box (esky in Aussie language) and that reduces the size of the fridge by about 30%

I can add more foam pieces or take the lot out when I need to dismember a body...

It makes a vast improvement on efficiency!

[Ex-Calif]

Originally Posted by MarkJ

I can add more foam pieces or take the lot out when I need to dismember a body...

We haven't heard from Nic in a while. Anything you want to talk about?

[DeepFrz]

Funny, I had just assumed for some reason that refrigerator and freezer were separate units and you all thought that they were a shared unit. Kind of difficult giving advice when we have no idea what we are advicing about...

[s/v Beth]

I agree with DF. I am giving advice on someone's refrig which I have no idea of. That it was charged two years ago and is freezing meat sound to me its still good. I would check insulation and make sure the freezer part has flow into the frig part. (Assuming that is what he has)