Re: Refrigerator monitor ideas?

["Robert Green" <ROBERT_GREEN1963@xxxxxxxxx>]

"Robert L Bass" <no-sales-spam@bassburglaralarms> wrote in message
news:89-dnWxAS6TJD17YnZ2dnUVZ_uCinZ2d@xxxxxxxxxxxxxx
> Robert,
>
> A temperature monitor in the freezer itself will warn of problems from
multiple causes.

By time a temperature monitor alerts me, the coil is usually a solid block
of ice.  That means the solution is not just unplugging the unit for a few
hours, it's pulling the floor of the freezer compartment and pouring hot
water over the coils until the ice melts.  I've even made a hot water
"enema" out of a soda bottle and some surgical tubing to insert into the
frozen drain hole to clear it.  It's very messy, though.  To catch the
beginning of an "ice up" via temp. monitor I would have to be able to
calculate the average daily temperature (when running correctly) and then
look for upward trends.   That gets complicated very quickly and has two
problems.  One is that it will likely take a PC to process the data.  The
other is that any change of the freezer control dial will affect the
system's balance.  I'd also have to account for the brief upward temperature
bursts each time the door is opened.

The most critical place to look is the connector from the bottom of the
freezer pan that goes to the drain hose at the back.  It has a little
plastic tab in the center of the hole designed to keep large items from
going into the drain tube.  That's where all the dog hair matted together
and formed a blockage.  A sensor there might be able to tell me when a clog
had formed.  When the clog does form, water no longer reaches the rear hose
nor the evaporator pan on the floor.  That's a condition that's probably
easier to check.

Since reefer condensate lines are gravity-operated, there's not much hope of
using a filter on the existing small diameter hose unless I can find a
filter that's got two small openings and a huge filter compartment.
Cosmetics are not a great issue in this particular icebox.  With a large
filter area, there's a lot less chance of a clog forming

> Additionally, consider placing a couple of  slow-release algaecide tablets
in the pan.
> Algae is a common cause of clogged drains under fridges, freezers and A/C
air
> handlers.

The freeze-up is occurring very high up in the system, right where the
freezer drain empties into the connector at the top of the refrigeration
compartment.  That connector goes from the drain at the bottom of the
freezer pan to the drain hose that runs down the back of the unit.

I'm assuming when dog hair builds up at the tab in the connector (as it's
designed to do) it eventually causes the condensate water to back up into
the freezer drain plug where it freezes.  When that happens, each defrost
cycle adds more and more ice to the frozen coils.  I want to detect when the
ice dam at the drain *first* appears when treatment involves just removing
the freezer pan-to-drain tube connector and cleaning it.   The solution
might just be to increase inspection rates, but I'd rather have some sort of
warning system.

> Our service drops a couple of tablets in the pan under each air handler
several times
> a year and that seems to keep the pipes clear.

This problem, as I said, is far upstream of the pan on the floor.  It used
to occur every few years and yearly inspection took care of it.  Now that my
wife's in the dog rescue business (and business is booming now that all the
Christmas puppies are being taken to the pound!) there's lots and lots of
dog hair around that didn't used to be.  Couple that with the location in
the basement and our house's proximity to a major thoroughfare and you can
see why I am pretty confident algaecide won't be helpful although improved
air cleaning near the box might.  The big problem with the floor evaporator
pan is all the calcium that builds up over time, but a little vinegar clears
that right up.

--
Bobby G.