Good Hardware Tools

On Fri, 27 Nov 2020 06:58:53 -0800 (PST), Rick C wrote:

<snip>
>
>How does your refrigerator control the temperatures of the two compartments when using a single compressor?  

I have not looked into it, but it does. The previous one (an 20+
years old Bosch) did it too. There is no air connection between
freeze and cool department. Both the old and new fridge both have a
digital display where you set freeze and  cool temperatures
independently. They must have some valve or other control thing for
it. In fact, some fridges have even different temparature zones
inside the cooler department. 

>If you set your refrigerator to -3&deg;C, don't things freeze?  My fridge would sometimes freeze things in the bottom when the temperature was set below 40&deg;F (5&deg;C).  

Never, because cool and freeze are completely independent, even
though they must share the same motor, at least on my model, a
Liebherr CP4813.  The energy differences between modern fridges can
run in the hundreds of kWhs per year, according to a consumer test
here; energy use was a selection criteria for us.

Mat Nieuwenhoven

On 11/28/2020 9:04 AM, Mat Nieuwenhoven wrote:
> I have not looked into it, but it does. The previous one (an 20+
> years old Bosch) did it too. There is no air connection between
> freeze and cool department. Both the old and new fridge both have a
> digital display where you set freeze and  cool temperatures
> independently. They must have some valve or other control thing for
> it. In fact, some fridges have even different temparature zones
> inside the cooler department.

This is increasingly common, here, with "multiple compartment" (> 2)
units.  A separate evaporator in each compartment allows the temperature
in each to be independently controlled.  So, you can opt to have two
freezer compartments, a refrigerator compartment and a "chiller"
compartment.  Or, some other combination (up to and including
all refrigerator or freezer)

Each compartment independently "calls for cooling", as needed.  If
any do so, the compressor is started and refrigerant gated through
the applicable evaporator.

Sadly, we've been "waved off" of many of the units we've looked at
as too costly and short lifespan (based on industry insiders).
I'd rather spend money for electricity and KNOW my 'frig is
going to keep running than worry about it sh*tting the bed while
full of foodstuffs!  Then I'd be faced with needing to find a
repair/replacement ASAP (and there is some opportunity cost, there)

On Saturday, November 28, 2020 at 11:04:11 AM UTC-5, Mat Nieuwenhoven wrote:
> On Fri, 27 Nov 2020 06:58:53 -0800 (PST), Rick C wrote: 
> 
> <snip>
> > 
> >How does your refrigerator control the temperatures of the two compartments when using a single compressor?
> I have not looked into it, but it does. The previous one (an 20+ 
> years old Bosch) did it too. There is no air connection between 
> freeze and cool department. Both the old and new fridge both have a 
> digital display where you set freeze and cool temperatures 
> independently. They must have some valve or other control thing for 
> it. In fact, some fridges have even different temparature zones 
> inside the cooler department.

Being able to set independent temperatures does not mean there are two coils with valves.  It is much more likely to have a controlled damper to modulate the amount of cold air from the freezer entering the refrigerator.   My refrigerator has a fan, but I can't say for sure where it blows, freezer only or freezer and refrigerator.  


> >If you set your refrigerator to -3&deg;C, don't things freeze? My fridge would sometimes freeze things in the bottom when the temperature was set below 40&deg;F (5&deg;C).
> Never, because cool and freeze are completely independent, even 
> though they must share the same motor, at least on my model, a 
> Liebherr CP4813. The energy differences between modern fridges can 
> run in the hundreds of kWhs per year, according to a consumer test 
> here; energy use was a selection criteria for us. 

Sorry, I can't follow your reasoning.  If you set the refrigerator temperature to -3&deg;C, it should freeze things.  Do I misunderstand the Celsius scale?  Or does your refrigerator not keep things at the set temperature?  

-- 

Rick C.

++- Get 1,000 miles of free Supercharging
++- Tesla referral code - https://ts.la/richard11209

On 2020-11-28, Mat Nieuwenhoven <mnieuw@zap.a2000.nl> wrote:
> On Fri, 27 Nov 2020 06:58:53 -0800 (PST), Rick C wrote:
>
><snip>
>>
>>How does your refrigerator control the temperatures of the two
>>compartments when using a single compressor?

Well, a lot of european refrigerators do have two compressors. I know
mine does. There's no air connection between freezer and refrigerator
and there are two completely separate thermostats.

> I have not looked into it, but it does. The previous one (an 20+
> years old Bosch) did it too.

Maybe they had two compressors. I thought most Bosch ones did.

--
Grant

On Saturday, November 28, 2020 at 3:53:57 PM UTC-5, Grant Edwards wrote:
> On 2020-11-28, Mat Nieuwenhoven <mni...@zap.a2000.nl> wrote: 
> > On Fri, 27 Nov 2020 06:58:53 -0800 (PST), Rick C wrote: 
> > 
> ><snip> 
> >> 
> >>How does your refrigerator control the temperatures of the two 
> >>compartments when using a single compressor?
> Well, a lot of european refrigerators do have two compressors. I know 
> mine does. There's no air connection between freezer and refrigerator 
> and there are two completely separate thermostats.
> > I have not looked into it, but it does. The previous one (an 20+ 
> > years old Bosch) did it too.
> Maybe they had two compressors. I thought most Bosch ones did. 

That has to be an expensive refrigerator.  Two of everything makes for a lot of works.  I can't see the need.  With the thermostat in the refrigerator and the evaporator around the freezer, the unit will run until the refrigerator is cold and by then the freezer will be adequately cold.  That can be adjusted by adjusting the air flow between the two.  I can't see adding a second compressor to take the place of an air damper.  

-- 

Rick C.

+++ Get 1,000 miles of free Supercharging
+++ Tesla referral code - https://ts.la/richard11209

On 11/28/20 6:16 PM, Rick C wrote:
> On Saturday, November 28, 2020 at 3:53:57 PM UTC-5, Grant Edwards wrote:
>> On 2020-11-28, Mat Nieuwenhoven <mni...@zap.a2000.nl> wrote: 
>>> On Fri, 27 Nov 2020 06:58:53 -0800 (PST), Rick C wrote: 
>>>
>>> <snip> 
>>>>
>>>> How does your refrigerator control the temperatures of the two 
>>>> compartments when using a single compressor?
>> Well, a lot of european refrigerators do have two compressors. I know 
>> mine does. There's no air connection between freezer and refrigerator 
>> and there are two completely separate thermostats.
>>> I have not looked into it, but it does. The previous one (an 20+ 
>>> years old Bosch) did it too.
>> Maybe they had two compressors. I thought most Bosch ones did. 
> 
> That has to be an expensive refrigerator.  Two of everything makes for a lot of works.  I can't see the need.  With the thermostat in the refrigerator and the evaporator around the freezer, the unit will run until the refrigerator is cold and by then the freezer will be adequately cold.  That can be adjusted by adjusting the air flow between the two.  I can't see adding a second compressor to take the place of an air damper.  
> 

You don't actually need a second compressor. You just need a seperate
cooler coil to cool the refrigerator compartment, and control valves to
select which cooling coils are being feed by the compressor based on the
demands.

On Saturday, November 28, 2020 at 8:57:43 PM UTC-5, Richard Damon wrote:
> On 11/28/20 6:16 PM, Rick C wrote: 
> > On Saturday, November 28, 2020 at 3:53:57 PM UTC-5, Grant Edwards wrote: 
> >> On 2020-11-28, Mat Nieuwenhoven <mni...@zap.a2000.nl> wrote: 
> >>> On Fri, 27 Nov 2020 06:58:53 -0800 (PST), Rick C wrote: 
> >>> 
> >>> <snip> 
> >>>> 
> >>>> How does your refrigerator control the temperatures of the two 
> >>>> compartments when using a single compressor? 
> >> Well, a lot of european refrigerators do have two compressors. I know 
> >> mine does. There's no air connection between freezer and refrigerator 
> >> and there are two completely separate thermostats. 
> >>> I have not looked into it, but it does. The previous one (an 20+ 
> >>> years old Bosch) did it too. 
> >> Maybe they had two compressors. I thought most Bosch ones did. 
> > 
> > That has to be an expensive refrigerator. Two of everything makes for a lot of works. I can't see the need. With the thermostat in the refrigerator and the evaporator around the freezer, the unit will run until the refrigerator is cold and by then the freezer will be adequately cold. That can be adjusted by adjusting the air flow between the two. I can't see adding a second compressor to take the place of an air damper. 
> >
> You don't actually need a second compressor. You just need a seperate 
> cooler coil to cool the refrigerator compartment, and control valves to 
> select which cooling coils are being feed by the compressor based on the 
> demands.

That's not the issue.  The issue is there is added cost with little gain.  Someone mentioned a unit with multiple freezer compartments.  It would be a very specialized use to need multiple freezer compartments in a single refrigerator.  None of that makes any sense to me. 

-- 

Rick C.

---- Get 1,000 miles of free Supercharging
---- Tesla referral code - https://ts.la/richard11209

On 29.11.20 4.07, Rick C wrote:
> On Saturday, November 28, 2020 at 8:57:43 PM UTC-5, Richard Damon wrote:
>> On 11/28/20 6:16 PM, Rick C wrote:
>>> On Saturday, November 28, 2020 at 3:53:57 PM UTC-5, Grant Edwards wrote:
>>>> On 2020-11-28, Mat Nieuwenhoven <mni...@zap.a2000.nl> wrote:
>>>>> On Fri, 27 Nov 2020 06:58:53 -0800 (PST), Rick C wrote:
>>>>>
>>>>> <snip>
>>>>>>
>>>>>> How does your refrigerator control the temperatures of the two
>>>>>> compartments when using a single compressor?
>>>> Well, a lot of european refrigerators do have two compressors. I know
>>>> mine does. There's no air connection between freezer and refrigerator
>>>> and there are two completely separate thermostats.
>>>>> I have not looked into it, but it does. The previous one (an 20+
>>>>> years old Bosch) did it too.
>>>> Maybe they had two compressors. I thought most Bosch ones did.
>>>
>>> That has to be an expensive refrigerator. Two of everything makes for a lot of works. I can't see the need. With the thermostat in the refrigerator and the evaporator around the freezer, the unit will run until the refrigerator is cold and by then the freezer will be adequately cold. That can be adjusted by adjusting the air flow between the two. I can't see adding a second compressor to take the place of an air damper.
>>>
>> You don't actually need a second compressor. You just need a seperate
>> cooler coil to cool the refrigerator compartment, and control valves to
>> select which cooling coils are being feed by the compressor based on the
>> demands.
> 
> That's not the issue.  The issue is there is added cost with little gain.  Someone mentioned a unit with multiple freezer compartments.  It would be a very specialized use to need multiple freezer compartments in a single refrigerator.  None of that makes any sense to me.
> 

There is the gain: you can keep the fridge slightly above freezing
and the freeze side well frozen if there are two cooling systems.
A single-compressor unit relies on suitable thermal leak out of
the fridge side to keep the temperature difference between the
compartments.

-- 

-TV

On Sat, 28 Nov 2020 20:53:51 +0000 (UTC), Grant Edwards wrote:

>On 2020-11-28, Mat Nieuwenhoven <mnieuw@zap.a2000.nl> wrote:
>> On Fri, 27 Nov 2020 06:58:53 -0800 (PST), Rick C wrote:
>>
>><snip>
>>>
>>>How does your refrigerator control the temperatures of the two
>>>compartments when using a single compressor?
>
>Well, a lot of european refrigerators do have two compressors. I know
>mine does. There's no air connection between freezer and refrigerator
>and there are two completely separate thermostats.
>
>> I have not looked into it, but it does. The previous one (an 20+
>> years old Bosch) did it too.
>
>Maybe they had two compressors. I thought most Bosch ones did.

I did not see a second compressor. There was one at the back, with on
top a kind of dish that caught the condensation runoff from the
cooler department via a hole, had to clean it once. The compressor
was at the level of the highest freeze drawer, which was shorter than
the other two. There must have been some valves controlling when a
compartment got cooling. The control was fully electronic on a single
PCB board.
I never heard different noises too, I think if there are two
compressors that at some times you'de hear both instead of one.
My current fridge also has a single compressor. 

I'm not sure that "a lot of european refrigerators" have two
compressors. Maybe the side-by-side fridges, they consume much more
energy.

Mat Nieuwenhoven

On Sat, 28 Nov 2020 15:16:07 -0800 (PST), Rick C wrote:

>On Saturday, November 28, 2020 at 3:53:57 PM UTC-5, Grant Edwards wrote:
>> On 2020-11-28, Mat Nieuwenhoven <mni...@zap.a2000.nl> wrote: 
>> > On Fri, 27 Nov 2020 06:58:53 -0800 (PST), Rick C wrote: 
>> > 
>> ><snip> 
>> >> 
>> >>How does your refrigerator control the temperatures of the two 
>> >>compartments when using a single compressor?
>> Well, a lot of european refrigerators do have two compressors. I know 
>> mine does. There's no air connection between freezer and refrigerator 
>> and there are two completely separate thermostats.
>> > I have not looked into it, but it does. The previous one (an 20+ 
>> > years old Bosch) did it too.
>> Maybe they had two compressors. I thought most Bosch ones did. 
>
>That has to be an expensive refrigerator.  Two of everything makes for a lot of works.  I can't see the need.  With the thermostat in the refrigerator and the evaporator around the freezer, the unit will run until the refrigerator is cold and by then the freezer will be adequately cold.  That can be adjusted by adjusting the air flow between the two.  I can't see adding a second compressor to take the place of an air damper.  

They really do have a single compressor, control is fully electronic,
and whatever they use for separate control must make it worthwhile,
they seem to use less energy judging from the brochures. Only the
cheapest fridges have a single mechanical control on the cooler
compartment. Seperate controls also mean that freezing in a large
numer of goods doesn't affect the cool compartment's temperature.

I don't know what you'd call expensive, ours was less than 800
euro's.

Mat Nieuwenhoven