On Wednesday, July 3, 2013 1:32:22 AM UTC-4, nestork wrote:
I like to think I know a fair bit about fridges, but I don't know what
you mean by "vent". Is this an air duct on the back wall of the fridge
with a baffle of some sort on it? Or are you referring to something on
the outside of the fridge.

Hi, nestork,

Yes, I do have to explain this. I've never seen a fridge design like this before, but I assumed that it was because I'm a throwback from a bygone era.. From my past, a normal fridge has an array of coils spread out over the back side.

This fridge is not like that. The back side is a solid wall. The coils are at the lower back corner of the fridge, and located inside of the rectangular volume of the fridge. In fact, it is hidden by a removal portion of the fridge's back wall. The coils are not spread out into a sheet, but stacked into a 3D cube. The fan is located between the coil stack and the compressor. It draws air across the coil stack and pushes it into the compressor. The compressor felt much warmer than the coils, so even the the air is warmed by its initial pass over the coils, it is still usable to cool the compressor. All 3 parts (coil stack, fan, compressor) are located *within* the rectangular volume of the fridge, at the lower back corner.

All the air that is driven by the fan to cool the coils and compressor is vented out the front of the fridge through openings at the bottom. How the air gets from the lower back part of the fridge to the front, I don't know. Some mechanical duct magic. And I don't know where the intake is either. I'll try to get at the back and take a picture.

No, if there was enough refrigerant leaking out of that fridge for
you to smell it, then the fridge wouldn't be working properly. Or,
it would be getting very much worse even as you read this.

Well it's a good sign that the deterioration hasn't been happening. I wasn't worried about refrigerant, however. More about machine oil or lubricant..

Three things:


1. In ANY fridge, the way to check the condition of the fridge is to
look at the frost formation on the evaporator coils. If this is a
frost free fridge; that is, one with a separate freezer compartment
with it's own door, then there will normally be a removable panel in
the freezer compartment, and the evaporator coil will be behind that
removable panel. If the fridge is in good health, then you should
see frost forming uniformly over the entire surface of the
evaporator coil. Frost forming only at one end of the evaporator
coil indicates a low refrigerant level (suggesting the possibility
of a leak), or a worn out compressor, or both. Sometimes, the
refrigerant charge will be so low that a "snowball" forms at the
inlet end of the evaporator coil, and the rest of the coil is frost
free. Seeing a uniform development of frost over the entire surface
area of the evaporator coil is proof that the fridge is in good
mechanical condition.

It's a strange hour of the night right now, but I'll check tomorrow. As I said, I was more suspecting oil/lubricant just due to the smell.

2. People spill food in fridges all the time. It doesn't smell
because the cold temperatures inside the fridge keep bacterial
growth to a minimum. So, what you could be smelling is some food
that was spilled in the freezer or fresh food section that seeped
into the cabinet of the fridge and to the outside of the insulation
where the warm temperatures would result in faster bacterial growth
and more smell.

Now this is something that I can respond to with confidence. It certainly isn't spilled food. I know some people whose fridge might be susceptible that, and my fridge is just the opposite.

3. A frost free fridge is nothing more than a manual defrost fridge
that has a system of defrosting itself every 10 to 20 hours. Frost
free fridges have an electric heater in them that is positioned in
close proximity to the evaporator coils. Once every 10 to 20 hours,
power from the fridge compressor will be diverted to that electric
heater to melt all the frost off the evaporator coils. The melt
water then travels down a tube running down the back of the fridge
to a receiving pan positioned above or around the compressor. The
heat from the warm compressor then helps re-evaporate that melt
water into the ambient air. It could be that someone spilled some
food in the freezer compartment. It's highly unlikely, but it could
be that food somehow got onto that defrost heater and is burning
every time the fridge defrosts itself. However, if that were the
case, you would notice the smell only when the heaters were
operating, which is for about 10 to 20 minutes every 10 to 20 hours.

I hinted that my fridge and freezer were very austere. In fact, the only things in the freezer are cold compress gel packs for sports injuries. The fridge section is quite austere and clean as well (but it does contain sealed food stuffs).

3 1/2: If this "vent" you refer to is a duct running along the back
wall of the fridge, it's purpose is to introduce cold air at the
BOTTOM of the fresh food compartment so that the circulation pattern
of that air through the fresh food compartment will keep the whole
fresh food compartment at a uniformly cold temperature. Since that
air comes from the area of the evaporator fan, it's possible that
what you're smelling is a fan motor slowly overheating and burning
the lacquer insulation on it's motor windings. If that's the case,
the evaporator fan motor is near or at the end of it's life and
would have to be replaced. If your fridge keeps cooling properly
for the next coupla weeks, then it wasn't the evaporator fan burning
itself up either.

I hope I have managed to clarify the the vented air is the air pulled by the fan over the coils and pushed over the compressor.