As our current unit is plainly struggling, I'm about to buy a new
frost-free combination fridge/frezer. But I'm confused about one
feature that is offered on some models and not others, namely
'Automatic defrost'. If the product is frost-free, then why would I
ever need to 'defrost' it? And I've seen posts which seem to imply
this feature is undesirable, and that manual defrosting is preferable.
The more I read, the more hazy the issue becomes!

Any crisp and clear advice on this would be greatly appreciated
please, as I need to place an order fast.

--
Terry Pinnell
Hobbyist, West Sussex, UK

On Mon, 09 Aug 2004 15:42:51 +0100, Terry Pinnell
wrote:

As our current unit is plainly struggling, I'm about to buy a new
frost-free combination fridge/frezer. But I'm confused about one
feature that is offered on some models and not others, namely
'Automatic defrost'. If the product is frost-free, then why would I
ever need to 'defrost' it? And I've seen posts which seem to imply
this feature is undesirable, and that manual defrosting is preferable.
The more I read, the more hazy the issue becomes!

Any crisp and clear advice on this would be greatly appreciated
please, as I need to place an order fast.

Frost free and automatic defrost are as far as I know the same thing.
I have one of these, and the freezer element is a flat vertical plate
at the back of the top cabinet. During the non-cooling phase the ice
melts to allow any excess to drip away through a pipe onto the
condenser bulb at the bottom, from which it evaporates into the room.

Mine has been working fine for many years.

The actual freezer bit at the bottom enjoys no such features, but it
only gathers frost when I have the thing too full and the door fails
to close properly. There is nothing for frost like a 1mm gap in the
door seal.

d

Pearce Consulting
http://www.pearce.uk.com

Terry Pinnell wrote:
As our current unit is plainly struggling, I'm about to buy a new
frost-free combination fridge/frezer. But I'm confused about one
feature that is offered on some models and not others, namely
'Automatic defrost'. If the product is frost-free, then why would I
ever need to 'defrost' it? And I've seen posts which seem to imply
this feature is undesirable, and that manual defrosting is preferable.
The more I read, the more hazy the issue becomes!

Any crisp and clear advice on this would be greatly appreciated
please, as I need to place an order fast.

Hi...

It's frost free because it auto defrosts

The upside is that you never have frost problems...

The downside is that energy consumption is slightly
increased (the fridge shuts down two or three times a
day and turns on a little electric heater to melt the
ice for a few minutes)

Ken

Ken Weitzel wrote:

Hi...

It's frost free because it auto defrosts

The upside is that you never have frost problems...

The downside is that energy consumption is slightly
increased (the fridge shuts down two or three times a
day and turns on a little electric heater to melt the
ice for a few minutes)

Don, Ken: Thanks both. Apprecaite the fast replies. But I don't see
how to square that with the fact that all the products I've researched
today seem to show these as two *independent* features. That's the
cause of my confusion.

For example, the HOTPOINT FFA70P at
http://www.comet.co.uk/comet/html/cache/30_823026.html
has Frost Free AND Automatic fridge defrost.

But the Bosch BOSCH KGU34124GB at
http://www.comet.co.uk/comet/html/cache/30_202096.html
has Frost Free but NOT Automatic fridge defrost.

--
Terry Pinnell
Hobbyist, West Sussex, UK

"Terry Pinnell" wrote in message
...
Ken Weitzel wrote:

Hi...

It's frost free because it auto defrosts

The upside is that you never have frost problems...

The downside is that energy consumption is slightly
increased (the fridge shuts down two or three times a
day and turns on a little electric heater to melt the
ice for a few minutes)

Don, Ken: Thanks both. Apprecaite the fast replies. But I don't see
how to square that with the fact that all the products I've researched
today seem to show these as two *independent* features. That's the
cause of my confusion.

For example, the HOTPOINT FFA70P at
http://www.comet.co.uk/comet/html/cache/30_823026.html
has Frost Free AND Automatic fridge defrost.

But the Bosch BOSCH KGU34124GB at
http://www.comet.co.uk/comet/html/cache/30_202096.html
has Frost Free but NOT Automatic fridge defrost.

--
Terry Pinnell
Hobbyist, West Sussex, UK


I have seen two systems at work in modern fridges. One is the heated
defrost (auto defrost). The other is sucking the humid air out of a
freezer every time you close the door (frost free). Make sense?

On Mon, 9 Aug 2004 12:56:07 -0500, "Derelict" wrote:


"Terry Pinnell" wrote in message
.. .
Ken Weitzel wrote:

Hi...

It's frost free because it auto defrosts

The upside is that you never have frost problems...

The downside is that energy consumption is slightly
increased (the fridge shuts down two or three times a
day and turns on a little electric heater to melt the
ice for a few minutes)

Don, Ken: Thanks both. Apprecaite the fast replies. But I don't see
how to square that with the fact that all the products I've researched
today seem to show these as two *independent* features. That's the
cause of my confusion.

For example, the HOTPOINT FFA70P at
http://www.comet.co.uk/comet/html/cache/30_823026.html
has Frost Free AND Automatic fridge defrost.

But the Bosch BOSCH KGU34124GB at
http://www.comet.co.uk/comet/html/cache/30_202096.html
has Frost Free but NOT Automatic fridge defrost.

--
Terry Pinnell
Hobbyist, West Sussex, UK


I have seen two systems at work in modern fridges. One is the heated
defrost (auto defrost). The other is sucking the humid air out of a
freezer every time you close the door (frost free). Make sense?


How do they do that? The air sucked out must be replaced by -
presumably - dry air. Where would that come from?

d

Pearce Consulting
http://www.pearce.uk.com

Don Pearce wrote:

On Mon, 9 Aug 2004 12:56:07 -0500, "Derelict" wrote:


"Terry Pinnell" wrote in message
.. .
Ken Weitzel wrote:

Hi...

It's frost free because it auto defrosts

The upside is that you never have frost problems...

The downside is that energy consumption is slightly
increased (the fridge shuts down two or three times a
day and turns on a little electric heater to melt the
ice for a few minutes)

Don, Ken: Thanks both. Apprecaite the fast replies. But I don't see
how to square that with the fact that all the products I've researched
today seem to show these as two *independent* features. That's the
cause of my confusion.

For example, the HOTPOINT FFA70P at
http://www.comet.co.uk/comet/html/cache/30_823026.html
has Frost Free AND Automatic fridge defrost.

But the Bosch BOSCH KGU34124GB at
http://www.comet.co.uk/comet/html/cache/30_202096.html
has Frost Free but NOT Automatic fridge defrost.

--
Terry Pinnell
Hobbyist, West Sussex, UK


I have seen two systems at work in modern fridges. One is the heated
defrost (auto defrost). The other is sucking the humid air out of a
freezer every time you close the door (frost free). Make sense?


How do they do that? The air sucked out must be replaced by -
presumably - dry air. Where would that come from?

No, it creates a partial vacuum. The sound of these freezers is very
distictive -- you hear a sucking sound when you close the door.

On Mon, 09 Aug 2004 13:31:54 -0700, Julie wrote:

Don Pearce wrote:

On Mon, 9 Aug 2004 12:56:07 -0500, "Derelict" wrote:


"Terry Pinnell" wrote in message
.. .
Ken Weitzel wrote:

Hi...

It's frost free because it auto defrosts

The upside is that you never have frost problems...

The downside is that energy consumption is slightly
increased (the fridge shuts down two or three times a
day and turns on a little electric heater to melt the
ice for a few minutes)

Don, Ken: Thanks both. Apprecaite the fast replies. But I don't see
how to square that with the fact that all the products I've researched
today seem to show these as two *independent* features. That's the
cause of my confusion.

For example, the HOTPOINT FFA70P at
http://www.comet.co.uk/comet/html/cache/30_823026.html
has Frost Free AND Automatic fridge defrost.

But the Bosch BOSCH KGU34124GB at
http://www.comet.co.uk/comet/html/cache/30_202096.html
has Frost Free but NOT Automatic fridge defrost.

--
Terry Pinnell
Hobbyist, West Sussex, UK


I have seen two systems at work in modern fridges. One is the heated
defrost (auto defrost). The other is sucking the humid air out of a
freezer every time you close the door (frost free). Make sense?


How do they do that? The air sucked out must be replaced by -
presumably - dry air. Where would that come from?

No, it creates a partial vacuum. The sound of these freezers is very
distictive -- you hear a sucking sound when you close the door.

Are you sure? To be of any use, a partial vacuum would have to be at
least, what? 4psi below atmospheric? Now my fridge door is about 20
inches by 30. That is 600 square inches. Multiply that by 4psi, and it
would take a pull of 2,400 pounds to open the door.

No.

d

Pearce Consulting
http://www.pearce.uk.com

Don Pearce wrote:

On Mon, 09 Aug 2004 13:31:54 -0700, Julie wrote:


Don Pearce wrote:

On Mon, 9 Aug 2004 12:56:07 -0500, "Derelict" wrote:


"Terry Pinnell" wrote in message
m...

Ken Weitzel wrote:


Hi...

It's frost free because it auto defrosts

The upside is that you never have frost problems...

The downside is that energy consumption is slightly
increased (the fridge shuts down two or three times a
day and turns on a little electric heater to melt the
ice for a few minutes)


Don, Ken: Thanks both. Apprecaite the fast replies. But I don't see
how to square that with the fact that all the products I've researched
today seem to show these as two *independent* features. That's the
cause of my confusion.

For example, the HOTPOINT FFA70P at
http://www.comet.co.uk/comet/html/cache/30_823026.html
has Frost Free AND Automatic fridge defrost.

But the Bosch BOSCH KGU34124GB at
http://www.comet.co.uk/comet/html/cache/30_202096.html
has Frost Free but NOT Automatic fridge defrost.

--
Terry Pinnell
Hobbyist, West Sussex, UK


I have seen two systems at work in modern fridges. One is the heated
defrost (auto defrost). The other is sucking the humid air out of a
freezer every time you close the door (frost free). Make sense?


How do they do that? The air sucked out must be replaced by -
presumably - dry air. Where would that come from?

No, it creates a partial vacuum. The sound of these freezers is very
distictive -- you hear a sucking sound when you close the door.


Are you sure? To be of any use, a partial vacuum would have to be at
least, what? 4psi below atmospheric? Now my fridge door is about 20
inches by 30. That is 600 square inches. Multiply that by 4psi, and it
would take a pull of 2,400 pounds to open the door.

No.

d


Hi Don...

And that would most likely require seals made by NASA - else
the vacuum would leak down quite rapidly anyway...

I have a stand alone chest freezer in the basement... if
you open it to get something, close it, change your mind
and try to open it again - you can't. For a very few
minutes.

In my humble opinion, just a sales gimmick...

Take care.

Ken

Hi Ken,

...(the fridge shuts down two or three times a day and turns on a
little electric heater to melt the
ice for a few minutes)

And that is often done with a lowly electro-mechanical timer. Probably
because it is still a few cents cheaper than electronics. After all, a
CD4060 costs north of 10 cents which would put a dent in the profit
margin on a $1000 fridge/freezer :-)

Regards, Joerg

http://www.analogconsultants.com

Terry Pinnell wrote:


Any crisp and clear advice on this would be greatly appreciated
please, as I need to place an order fast.

Still hoping to get that!

--
Terry Pinnell
Hobbyist, West Sussex, UK

Ken Weitzel wrote:



Don Pearce wrote:

On Mon, 09 Aug 2004 13:31:54 -0700, Julie wrote:


Don Pearce wrote:

On Mon, 9 Aug 2004 12:56:07 -0500, "Derelict" wrote:


"Terry Pinnell" wrote in message
...

Ken Weitzel wrote:


Hi...

It's frost free because it auto defrosts

The upside is that you never have frost problems...

The downside is that energy consumption is slightly
increased (the fridge shuts down two or three times a
day and turns on a little electric heater to melt the
ice for a few minutes)


Don, Ken: Thanks both. Apprecaite the fast replies. But I don't see
how to square that with the fact that all the products I've
researched
today seem to show these as two *independent* features. That's the
cause of my confusion.

For example, the HOTPOINT FFA70P at
http://www.comet.co.uk/comet/html/cache/30_823026.html
has Frost Free AND Automatic fridge defrost.

But the Bosch BOSCH KGU34124GB at
http://www.comet.co.uk/comet/html/cache/30_202096.html
has Frost Free but NOT Automatic fridge defrost.

--
Terry Pinnell
Hobbyist, West Sussex, UK


I have seen two systems at work in modern fridges. One is the heated
defrost (auto defrost). The other is sucking the humid air out of a
freezer every time you close the door (frost free). Make sense?


How do they do that? The air sucked out must be replaced by -
presumably - dry air. Where would that come from?


No, it creates a partial vacuum. The sound of these freezers is very
distictive -- you hear a sucking sound when you close the door.



Are you sure? To be of any use, a partial vacuum would have to be at
least, what? 4psi below atmospheric? Now my fridge door is about 20
inches by 30. That is 600 square inches. Multiply that by 4psi, and it
would take a pull of 2,400 pounds to open the door.

No.

d


Hi Don...

And that would most likely require seals made by NASA - else
the vacuum would leak down quite rapidly anyway...

I have a stand alone chest freezer in the basement... if
you open it to get something, close it, change your mind
and try to open it again - you can't. For a very few
minutes.

In my humble opinion, just a sales gimmick...


My freezer (which is not frost free) does that as well. I think it's
just the warm air which entered the freezer cooling down and contracting.


--
-----------------------------------------------------------------------
To reply to me directly:

Replace privacy.net with: totalise DOT co DOT uk and replace me with
gareth.harris

I read in sci.electronics.design that Joerg notthisjoergsch@removethisp
acbell.net wrote (in )
about 'Frost free / Auto defrost?', on Mon, 9 Aug 2004:
Hi Ken,

...(the fridge shuts down two or three times a day and turns on a
little electric heater to melt the
ice for a few minutes)

And that is often done with a lowly electro-mechanical timer. Probably
because it is still a few cents cheaper than electronics. After all, a
CD4060 costs north of 10 cents which would put a dent in the profit
margin on a $1000 fridge/freezer :-)

In mine, the heater is just wired across the thermostat contacts: COOL
XOR HEAT at zero cost.
--
Regards, John Woodgate, OOO - Own Opinions Only.
The good news is that nothing is compulsory.
The bad news is that everything is prohibited.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk

Don Pearce wrote:

On Mon, 09 Aug 2004 13:31:54 -0700, Julie wrote:

Don Pearce wrote:

On Mon, 9 Aug 2004 12:56:07 -0500, "Derelict" wrote:


"Terry Pinnell" wrote in message
.. .
Ken Weitzel wrote:

Hi...

It's frost free because it auto defrosts

The upside is that you never have frost problems...

The downside is that energy consumption is slightly
increased (the fridge shuts down two or three times a
day and turns on a little electric heater to melt the
ice for a few minutes)

Don, Ken: Thanks both. Apprecaite the fast replies. But I don't see
how to square that with the fact that all the products I've researched
today seem to show these as two *independent* features. That's the
cause of my confusion.

For example, the HOTPOINT FFA70P at
http://www.comet.co.uk/comet/html/cache/30_823026.html
has Frost Free AND Automatic fridge defrost.

But the Bosch BOSCH KGU34124GB at
http://www.comet.co.uk/comet/html/cache/30_202096.html
has Frost Free but NOT Automatic fridge defrost.

--
Terry Pinnell
Hobbyist, West Sussex, UK


I have seen two systems at work in modern fridges. One is the heated
defrost (auto defrost). The other is sucking the humid air out of a
freezer every time you close the door (frost free). Make sense?


How do they do that? The air sucked out must be replaced by -
presumably - dry air. Where would that come from?

No, it creates a partial vacuum. The sound of these freezers is very
distictive -- you hear a sucking sound when you close the door.

Are you sure? To be of any use, a partial vacuum would have to be at
least, what? 4psi below atmospheric? Now my fridge door is about 20
inches by 30. That is 600 square inches. Multiply that by 4psi, and it
would take a pull of 2,400 pounds to open the door.

I was speaking empirically, and not technically, my bad. It looks like I'm
wrong on my assumptions -- I retract my statements.

In article ,
Terry Pinnell wrote:
As our current unit is plainly struggling, I'm about to buy a new
frost-free combination fridge/frezer. But I'm confused about one
feature that is offered on some models and not others, namely
'Automatic defrost'. If the product is frost-free, then why would
I ever need to 'defrost' it? And I've seen posts which seem to
imply this feature is undesirable, and that manual defrosting is
preferable. The more I read, the more hazy the issue becomes!

We have three fridge/freezers Terry (don't ask why,
because I don't know).

Two of them are Hotpoint "frost free", and really not
worth the extra money and running costs. Overload
them just slightly, (which hampers the internal air
circulation), and the fridge compartment freezes up
(literally, a solid block of ice), whilst at the same
time everything in the freezer section starts to melt.

Don't bother with frost free.

The third is a Bosch auto-defrost, which works very well.

However I should have bought the more expensive Bosch,
which has separate compressors and thermostats for the
fridge and freezer compartments. That type works better
over a wider range of ambient temperatures.

--
Tony Williams.

John Woodgate wrote:

I read in sci.electronics.design that Joerg notthisjoergsch@removethisp
acbell.net wrote (in )
about 'Frost free / Auto defrost?', on Mon, 9 Aug 2004:
Hi Ken,

...(the fridge shuts down two or three times a day and turns on a
little electric heater to melt the
ice for a few minutes)

And that is often done with a lowly electro-mechanical timer. Probably
because it is still a few cents cheaper than electronics. After all, a
CD4060 costs north of 10 cents which would put a dent in the profit
margin on a $1000 fridge/freezer :-)

In mine, the heater is just wired across the thermostat contacts: COOL
XOR HEAT at zero cost.

But unless I've missed something, I've still not had answers to my
original questions. To recap:

1. Are 'Frost Free' and 'Auto Fridge Defrost' independent features
(not 'the same thing' as Ken and Don both said)? The evidence of my
research, as per the examples I gave, appear to imply that they are.

2. Why is 'defrost' necessary, if the unit is frost free? Is it just
an admission that the Frost Free thing doesn't always work?

3. Is 'Auto Fridge Defrost' a worthwhile feature?

--
Terry Pinnell
Hobbyist, West Sussex, UK

Tony Williams wrote:

We have three fridge/freezers Terry (don't ask why,
because I don't know).

Two of them are Hotpoint "frost free", and really not
worth the extra money and running costs. Overload
them just slightly, (which hampers the internal air
circulation), and the fridge compartment freezes up
(literally, a solid block of ice), whilst at the same
time everything in the freezer section starts to melt.

Don't bother with frost free.

The third is a Bosch auto-defrost, which works very well.

However I should have bought the more expensive Bosch,
which has separate compressors and thermostats for the
fridge and freezer compartments. That type works better
over a wider range of ambient temperatures.

Thanks, Tony. On the basis of that, plus the fact that our current
ailing Hotpointo suffered identical problems to those you describe,
I've just ordered a Bosch.

--
Terry Pinnell
Hobbyist, West Sussex, UK

Terry Pinnell wrote:
But unless I've missed something, I've still not had answers to my
original questions. To recap:

1. Are 'Frost Free' and 'Auto Fridge Defrost' independent features
(not 'the same thing' as Ken and Don both said)? The evidence of my
research, as per the examples I gave, appear to imply that they are.

2. Why is 'defrost' necessary, if the unit is frost free? Is it just
an admission that the Frost Free thing doesn't always work?

3. Is 'Auto Fridge Defrost' a worthwhile feature?

Yes.

Terry --
While I cannot answer your first two exact questions authoritatively, I
would be willing to wager almost any amount that no refrigerator will be
frost free without use of an auto defrost feature.

--
John Miller
Email address: domain, n4vu.com; username, jsm

He is not only dull himself, he is the cause of dullness in others.
-Samuel Johnson

John Woodgate writes:

I read in sci.electronics.design that Joerg notthisjoergsch@removethisp
acbell.net wrote (in )
about 'Frost free / Auto defrost?', on Mon, 9 Aug 2004:
Hi Ken,

...(the fridge shuts down two or three times a day and turns on a
little electric heater to melt the
ice for a few minutes)

And that is often done with a lowly electro-mechanical timer. Probably
because it is still a few cents cheaper than electronics. After all, a
CD4060 costs north of 10 cents which would put a dent in the profit
margin on a $1000 fridge/freezer :-)

It's not only the cost of a CD4060. Add in the power supply and other
low power components for it (a few cents) and the power relays needed to
switch the compressor circuit and heater circuit.

In mine, the heater is just wired across the thermostat contacts: COOL
XOR HEAT at zero cost.

So you heat your food when the compressor isn't running? That forms
an oscillator with a frequency dependant on ambient temperature and
the quality of the fridge's insulation. I guess what you mean is
that it defrosts until another thermostat says there isn't any more ice.

--- sam | Sci.Electronics.Repair FAQ Home Page: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Site Info: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header is ignored.
To contact me, please use the feedback form on the S.E.R FAQ Web sites.

Terry Pinnell wrote:
As our current unit is plainly struggling, I'm about to buy a new
frost-free combination fridge/frezer. But I'm confused about one
feature that is offered on some models and not others, namely
'Automatic defrost'. If the product is frost-free, then why would I
ever need to 'defrost' it? And I've seen posts which seem to imply
this feature is undesirable, and that manual defrosting is preferable.
The more I read, the more hazy the issue becomes!

Any crisp and clear advice on this would be greatly appreciated
please, as I need to place an order fast.


No refrigerator in the world will operate without frost if you block the
drain for the frost water with debris and/or scum formation:-) Those UK
refrigerators you cited would be considered miniature doll-house
accessories in the US- absolutely tiny. How cramped are the quarters in
that country anyway?

"Fred Bloggs" schreef in bericht
...


Terry Pinnell wrote:
As our current unit is plainly struggling, I'm about to buy a new
frost-free combination fridge/frezer. But I'm confused about one
feature that is offered on some models and not others, namely
'Automatic defrost'. If the product is frost-free, then why would I
ever need to 'defrost' it? And I've seen posts which seem to imply
this feature is undesirable, and that manual defrosting is preferable.
The more I read, the more hazy the issue becomes!

Any crisp and clear advice on this would be greatly appreciated
please, as I need to place an order fast.


No refrigerator in the world will operate without frost if you block the
drain for the frost water with debris and/or scum formation:-) Those UK
refrigerators you cited would be considered miniature doll-house
accessories in the US- absolutely tiny. How cramped are the quarters in
that country anyway?

I have a second refrigerator in my hobby workshop. I runs on a peltier
cooler, and can hold 6 cans of coke.

You don't see many double door refrigerators in Europe. The average
kitchen is too small and it's easier to go to the shop and get it fresh,
instead of piling it all up in your fridge. Or borrow what you need
from the neighbours

--
Thanks, Frank.
(remove 'x' and 'invalid' when replying by email)

See if this makes any sense:

Frost Free - means frost does not grow around the doors, due to small
heating elements embedded around the door frame.

Auto defrost - operates on a timer, or counter that shuts down the
compressor and turns on a heating element (350 - 500 W) that heats up the
evaporator to melt any accumulated frost. The time frame for the timer is
around a few days to a week, and the system uses a counter, it's operated by
the number of times the door is opened.


"Terry Pinnell" wrote in message
...
As our current unit is plainly struggling, I'm about to buy a new
frost-free combination fridge/frezer. But I'm confused about one
feature that is offered on some models and not others, namely
'Automatic defrost'. If the product is frost-free, then why would I
ever need to 'defrost' it? And I've seen posts which seem to imply
this feature is undesirable, and that manual defrosting is preferable.
The more I read, the more hazy the issue becomes!

Any crisp and clear advice on this would be greatly appreciated
please, as I need to place an order fast.

--
Terry Pinnell
Hobbyist, West Sussex, UK

Frank Bemelman wrote:
"Fred Bloggs" schreef in bericht
...


Terry Pinnell wrote:

As our current unit is plainly struggling, I'm about to buy a new
frost-free combination fridge/frezer. But I'm confused about one
feature that is offered on some models and not others, namely
'Automatic defrost'. If the product is frost-free, then why would I
ever need to 'defrost' it? And I've seen posts which seem to imply
this feature is undesirable, and that manual defrosting is preferable.
The more I read, the more hazy the issue becomes!

Any crisp and clear advice on this would be greatly appreciated
please, as I need to place an order fast.


No refrigerator in the world will operate without frost if you block the
drain for the frost water with debris and/or scum formation:-) Those UK
refrigerators you cited would be considered miniature doll-house
accessories in the US- absolutely tiny. How cramped are the quarters in
that country anyway?


I have a second refrigerator in my hobby workshop. I runs on a peltier
cooler, and can hold 6 cans of coke.

You don't see many double door refrigerators in Europe. The average
kitchen is too small and it's easier to go to the shop and get it fresh,
instead of piling it all up in your fridge. Or borrow what you need
from the neighbours


It is a bad habit to drink Coke at home. I do drink it at work because
the water is extracted from a well bored through a former toxic chemical
refuse dump and the "old timers" have advised against drinking it-)-
not to mention the recent e.coli contamination bulletin.

I read in sci.electronics.design that Sam Goldwasser
wrote (in )
about 'Frost free / Auto defrost?', on Tue, 10 Aug 2004:

So you heat your food when the compressor isn't running?
'Heat' is a big word. It's about a 5 W heater embedded in the cooling
coil plate.

That forms an
oscillator with a frequency dependant on ambient temperature and the
quality of the fridge's insulation. I guess what you mean is that it
defrosts until another thermostat says there isn't any more ice.

No, just the one thermostat. It opens at about 0 C, stopping the
compressor, and the heater then warms up the plate to about 5 C, when
the thermostat closes again and cuts off the heat. I won't go to law on
the precise temperatures.
--
Regards, John Woodgate, OOO - Own Opinions Only.
The good news is that nothing is compulsory.
The bad news is that everything is prohibited.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk

I read in sci.electronics.design that Fred Bloggs
wrote (in ) about 'Frost free / Auto
defrost?', on Tue, 10 Aug 2004:

How cramped are the quarters in
that country anyway?

The floor plan of my bungalow is 40 ft by 20 ft. Individual rooms in
quite modest US houses are bigger than that.
--
Regards, John Woodgate, OOO - Own Opinions Only.
The good news is that nothing is compulsory.
The bad news is that everything is prohibited.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk

John Woodgate writes:

How cramped are the quarters in
that country anyway?

The floor plan of my bungalow is 40 ft by 20 ft. Individual rooms in
quite modest US houses are bigger than that.

Maybe in McMansions. Not most of the more than modest homes
around where we live.

--- sam | Sci.Electronics.Repair FAQ Home Page: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
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"John Woodgate" wrote in message
...
I read in sci.electronics.design that Sam Goldwasser
wrote (in )
about 'Frost free / Auto defrost?', on Tue, 10 Aug 2004:

So you heat your food when the compressor isn't running?
'Heat' is a big word. It's about a 5 W heater embedded in the cooling
coil plate.
These systems normally also have a fan from the cooler module. This is
switched off, when the cooler is being defrosted. So the main freezer
contents only 'warm', by perhaps half a degree in the entire cycle.

That forms an
oscillator with a frequency dependant on ambient temperature and the
quality of the fridge's insulation. I guess what you mean is that
it
defrosts until another thermostat says there isn't any more ice.

No, just the one thermostat. It opens at about 0 C, stopping the
compressor, and the heater then warms up the plate to about 5 C, when
the thermostat closes again and cuts off the heat. I won't go to law on
the precise temperatures.
It is worth making a comment here about the 'Hotpoint' units, that have
had some significant bad reports here. I have one. A few months from new,
it developed the sort of problem being discussed. The engineer who came
said it was a known problem with the module, and replaced it with a new
design. The original system was a fairly basic mechanical timer, and
thermostat. The new module was a solid state system, with a temperature
pickup that had to be attached to the cooler assembly. I have had this now
for over eighteen months, without any problems at all. Hopefully new units
would have this design.

Best Wishes

Sam Goldwasser wrote:

John Woodgate writes:

How cramped are the quarters in
that country anyway?

The floor plan of my bungalow is 40 ft by 20 ft. Individual rooms in
quite modest US houses are bigger than that.

Maybe in McMansions. Not most of the more than modest homes
around where we live.

True. I've never seen a single room that big. But one time I moved
from a relatively small rooming house to an apartment, and my Dad
remarked, "The bathroom is bigger than the room you used to live in!"

Cheers!
Rich

John Woodgate wrote:

I read in sci.electronics.design that Sam Goldwasser
wrote (in )
about 'Frost free / Auto defrost?', on Tue, 10 Aug 2004:

So you heat your food when the compressor isn't running?
'Heat' is a big word. It's about a 5 W heater embedded in the cooling
coil plate.

That forms an
oscillator with a frequency dependant on ambient temperature and the
quality of the fridge's insulation. I guess what you mean is that it
defrosts until another thermostat says there isn't any more ice.

No, just the one thermostat. It opens at about 0 C, stopping the
compressor, and the heater then warms up the plate to about 5 C, when
the thermostat closes again and cuts off the heat. I won't go to law on
the precise temperatures.

John, would it be possible to humor me and take some actual temp.
measurements? I can't imagine a freezer with a chill plate at only
0 C doing much freezing of stuff at all.

Thanks,
Rich

I read in sci.electronics.design that Rich Grise
wrote (in ) about 'Frost free /
Auto defrost?', on Tue, 10 Aug 2004:
John, would it be possible to humor me and take some actual temp.
measurements? I can't imagine a freezer with a chill plate at only 0 C
doing much freezing of stuff at all.

Sorry, my numbers refer to the *fridge* section defroster. I don't know
how the freezer defrosts. I'll ask someone who knows, but he often
doesn't answer.
--
Regards, John Woodgate, OOO - Own Opinions Only.
The good news is that nothing is compulsory.
The bad news is that everything is prohibited.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk

Hi Terry,

1. Are 'Frost Free' and 'Auto Fridge Defrost' independent features
(not 'the same thing' as Ken and Don both said)? The evidence of my
research, as per the examples I gave, appear to imply that they are.

2. Why is 'defrost' necessary, if the unit is frost free? Is it just
an admission that the Frost Free thing doesn't always work?

3. Is 'Auto Fridge Defrost' a worthwhile feature?


I'd side with John. Whenever you open a freezer or fridge door some air
will enter. That air has a certain humidity. Now some of that humidity
will condense on the walls and freeze there. That is inevitable. Same if
you don't open the door, just slower. That is because no door seal is
going to be 100% tight.

I have yet to see a frost free unit that doesn't have an auto-defrost
feature.

In the olden days the defroster was a human. We had to turn off the
fridge, leave the door cracked and then take the little container of
water out. And clean whatever had spilled. Then came the auto-defrosters
where you still had to remember to check that container in there or
it'll spill over. The amount of water in there depended on the weather
and all. The current state of the art appears to be the auto-defroster
that has a little hose which guides the water outside into a little
tray. In ours that tray is within the outside blower airflow so it
evaporates enough that we hardly have to worry about it overflowing. But
it still needs to be scrubbed regularly or molds might grow.

Regards, Joerg

http://www.analogconsultants.com

Hi Sam,

It's not only the cost of a CD4060. Add in the power supply and other
low power components for it (a few cents) and the power relays needed to
switch the compressor circuit and heater circuit.


No need for a compressor relay since that is already handled by the
thermostat. The defroster only receives power when the compressor is
off. So that only leaves a tiny triac or so to turn on that little
heater loop. Ok, the triac would add a few cents here. But the whole
thing wouldn't break so often anymore.

Our fancy combo had cost way over $1000 yet it has broken down twice in
five year. The ol' Bosch in the basement is from 1958, never broke down,
can't even remember whether it ever asked for a new light bulb.

Regards, Joerg

http://www.analogconsultants.com

Joerg writes:

Hi Sam,

It's not only the cost of a CD4060. Add in the power supply and other
low power components for it (a few cents) and the power relays needed to
switch the compressor circuit and heater circuit.

No need for a compressor relay since that is already handled by the
thermostat. The defroster only receives power when the compressor is
off. So that only leaves a tiny triac or so to turn on that little
heater loop. Ok, the triac would add a few cents here. But the whole
thing wouldn't break so often anymore.

In the systems I've seen, the timer also turns off the compressor
if it is on since it's possible for the compressor to be running 24/7 in
very extreme conditions and then there would be no defrost.

Typical circuit from GE Frost Free:

Black (4)
Gray (3) /o---------o Normal position - Compressor, evaporator fan.
H* o-----+------/
| o---o Blue (2)
Timer | Defrost heater Defrost Thermostat
Motor (3180 o------------/\/\/\------------o/o----------+
| ohms) 31 ohms 32 F |
| |
| Orange (1) |
o---------------------------------------------------------+--o Common

* H is the Hot wire after passing through the main thermostat (cold control)
in the fresh food compartment.

The contacts switching the black and blue wires is controlled by the timer.

Our fancy combo had cost way over $1000 yet it has broken down twice
in five year. The ol' Bosch in the basement is from 1958, never broke
down, can't even remember whether it ever asked for a new light bulb.

Yep!

--- sam | Sci.Electronics.Repair FAQ Home Page: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Site Info: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header is ignored.
To contact me, please use the feedback form on the S.E.R FAQ Web sites.

John Woodgate wrote:
I read in sci.electronics.design that Fred Bloggs
wrote (in ) about 'Frost free / Auto
defrost?', on Tue, 10 Aug 2004:


How cramped are the quarters in
that country anyway?


The floor plan of my bungalow is 40 ft by 20 ft. Individual rooms in
quite modest US houses are bigger than that.

I live in a 650 sq ft space and still have a 14 cu ft refrigerator, in
addition to every other appliance known to mankind. It feels bigger than
it sounds because of the cathedral ceilings, skylights, and floor plan.
This area is rightly pursuing high density housing in an attempt to
staunch the so-called urban sprawl and all the damaging and wasteful
aftermath associated with it. The 650 sq ft is quite large when you
consider that it is situated in a 20 acre park setting with two pools,
tennis courts, jogging trails, 24-hour fitness center, indoor handball
courts, private parking, sound barrier, immaculately maintained grounds
and infrastructure, and centrally located within urban neighborhood
requiring no travel whatsoever- not 1/2 mile direct from a choice of two
mega-supermarkets for example. It was either this place or a townhouse,
but when I took the tour, I was immediately sold on the efficiency of
the compactness- and fully intend to buy the place once I save up about
five million dollars.

Fred Bloggs wrote:



John Woodgate wrote:
I read in sci.electronics.design that Fred Bloggs
wrote (in ) about 'Frost free / Auto
defrost?', on Tue, 10 Aug 2004:


How cramped are the quarters in
that country anyway?


The floor plan of my bungalow is 40 ft by 20 ft. Individual rooms in
quite modest US houses are bigger than that.

I live in a 650 sq ft space and still have a 14 cu ft refrigerator, in
addition to every other appliance known to mankind. It feels bigger than
it sounds because of the cathedral ceilings, skylights, and floor plan.

Now those *are* features we just don't get in our fridges here...

--
Terry Pinnell
Hobbyist, West Sussex, UK