Nikon is backwards

In article , Alan Browne
wrote:

Personal experience always beats reading things on google.

Sounds a bit like the reasoning of a flat earther

Bull****, I do not experience flat earth.

you do if you put a ball on the ground and it does not move.

I thought that with flat earth it ran to the middle. :-)

that's the bowl theory, which is how satellites orbit. they simply go
around the edge of the bowl.

All that math and physics I wasted time on...

this should clarify things:
https://wiki.tfes.org/images/f/f8/Orlando_Ferguson_Map.jpg

On 2019-03-03 18:51, nospam wrote:
In article , Alan Browne
wrote:

Personal experience always beats reading things on google.

Sounds a bit like the reasoning of a flat earther

Bull****, I do not experience flat earth.

you do if you put a ball on the ground and it does not move.

I thought that with flat earth it ran to the middle. :-)

that's the bowl theory, which is how satellites orbit. they simply go
around the edge of the bowl.

All that math and physics I wasted time on...

this should clarify things:
https://wiki.tfes.org/images/f/f8/Orlando_Ferguson_Map.jpg

Of course. If it's based in the Bible there is no other explanation to
ponder. Silly me.


--
"2/3 of Donald Trump's wives were immigrants. Proof that we
need immigrants to do jobs that most Americans wouldn't do."
- unknown protester

On Sun, 03 Mar 2019 17:32:48 -0000, "Commander Kinsey"
wrote:

On Sun, 03 Mar 2019 09:03:18 -0000, Eric Stevens wrote:

On Sun, 03 Mar 2019 02:11:48 -0000, "Commander Kinsey"
wrote:

On Sun, 03 Mar 2019 02:02:39 -0000, Eric Stevens wrote:

On Sat, 02 Mar 2019 23:55:04 -0000, "Commander Kinsey"
wrote:

On Sat, 02 Mar 2019 09:16:20 -0000, Eric Stevens wrote:

On Sat, 02 Mar 2019 00:06:08 -0000, "Commander Kinsey"
wrote:

On Fri, 01 Mar 2019 23:01:27 -0000, Eric Stevens wrote:

On Fri, 01 Mar 2019 22:27:34 -0000, "Commander Kinsey"
wrote:

---snip ---

Only if they get really clogged up. The defrost cycle is only initiated to make more room so you don't get half the cavity filled with ice where you want to place food. It cools just fine even though the coils are covered in ice. In fact older ones didn't auto defrost at all. You could leave them forever all frozen up and just get a smaller and smaller food compartment.

Ice is not a good heat conductor and the accumulation of ice does is
to ensure your freezer is at or slightly below 0C whereas the design
temperature is probably -18C. As the ice builds up the temperature
inside the freezer will slowly rise while the power consumptiom of the
freezer increases.

No, the freezer remains at -18C or below just fine. And you'll find ice is a very good conductor. Place some cold ice from a freezer on your hand and feel how much heat it pulls from you. It's probably as good as metal.

What you are sensing is the effect of your hand providing the latent
heat to melt the ice. The thermal conductivity of ice depends upon how
the ice was formed but typically is about 2.5 W/mK (see
https://www.engineeringtoolbox.com/i...ies-d_576.html )
The thermal conductivity of the aluminium upon which the ice is
forming is 200 W/mK or more. The thermal conductivity of copper is 385
W/mK. See
https://chemistry.tutorvista.com/phy...aluminium.html

If ice didn't conduct much, then you wouldn't melt it with your hand very fast.

Why do you say that? It's the surface that your hand is warming and as
soon it is warmed it flows away, exposing more ice.

It has to conduct heat from your hand to the ice.

What is 'it'?

The ice.

That's what you seemed to have said: the ice has to conduct heat from
your hand to the ice. What have you been smoking.

Of course heat goes from your hand to the ice, what's wrong with you?

But you have just said the heat from your hand goes through the ice to
the ice. It doesn't. It goes from your hand to the surface of the ice
and it is the surface of the ice which melts and flows away.

See when you jump in a cold lake, it feels colder than the air? Water is a good conductor of heat. Ice is just frozen water.

I see you ignored this part.

So that makes ice a good conductor of heat too. How old were you when
you left school?

It's the same substance you fool.

Everything you write increases my doubt that you have any kind of
qualification in physis.

It's the same substance only to the extent that they are both composed
of H-O-H. The H-O-H is much more tightly bonded in ice than it is in
water and it takes energy to break that bond (latent heat). Heat is
conducted by exciting the individual H-O-H in one way or another.
Being bound in position, the H-O-H of ice are not free to transfer
excitation energy in the same way as the H-O-H in liquid water. Hence
ice is not as good a heat conductor.

2. They are designed (including sized) to operate in that
condition.

Then the heat pumps should be designed in the same way. And they are, plenty of them can cope with sub zero outdoor temperatures.

That's why I said to be careful as there are also plenty of them which
can't.

Yes, there's always some ****wit designer who makes a device to heat a house which only works when it's already warm outside. Doh!

Depends upon your definition of warm.

Well you said they won't work below 6C. Consider a country that never goes below 6C. That's a warm country. One not worth bothering to install a heat pump in.

No I didn't. I said there can be problems below 6C.

If there are problems, that means it isn't working. The definition of working is something operating without problems.

3. There is probably something wrong if if the coils are permanently
heavily iced up. But possibly, it is either a very old or cheap
design. In any case, it will be more expensive to run if it is
permanently operating with the coils severely iced up.

Defrosting them when they're iced up a little bit is pointless.

Why do you say that?

The defroster would be on all the time and simply keep adding heat back in.

That's not too serious considering that it is heat you are after.

I was considering a freezer, which clearly manages just fine without continually heating the coils.

We were talking about heat pumps to heat a house. A freezer turns the
problem inside out.

It's the same device. You're moving heat from a cold place to a warm place. If a freezer can do it when the cold side is -18C, then a house heat pump can do the same at more than -18C.

Once it has cooled down an insulated freezer has to pump very little
heat from the interior. The same does not apply to a heat pump trying
to keep a house hot.

What about a freezer at -10C? It gets from there to -18C pretty easily.

And the evaporator coils in the heater are ice free.

At -10C? I doubt it.

When you start a clean freezer from it's initial condition the coils
are ice free. Providing it is closed and the door seals work there
will be insufficient water vapour in the freezer to cause significant
icing as the temperature drops from the dew point to 0C. Such
condensation as there may be willdrop from the evaporator as it forms.
The situation will be different if you are using the freezer to
freeze-dry your laundry.
--

Regards,

Eric Stevens

On Sun, 03 Mar 2019 02:13:19 -0000, "Commander Kinsey"
wrote:

On Sun, 03 Mar 2019 02:07:34 -0000, Eric Stevens wrote:

On Sat, 02 Mar 2019 23:57:33 -0000, "Commander Kinsey"
wrote:

On Sat, 02 Mar 2019 18:31:43 -0000, Alan Browne wrote:

On 2019-03-01 17:27, Commander Kinsey wrote:
On Fri, 01 Mar 2019 01:30:18 -0000, Eric Stevens
wrote:

On Wed, 27 Feb 2019 23:48:53 -0000, "Commander Kinsey"
wrote:

On Wed, 27 Feb 2019 22:38:00 -0000, Eric Stevens
wrote:

On Wed, 27 Feb 2019 20:28:30 -0000, "Commander Kinsey"
wrote:

On Wed, 27 Feb 2019 04:00:58 -0000, Eric Stevens
wrote:

On Wed, 27 Feb 2019 01:47:36 -0000, "Commander Kinsey"
wrote:

On Tue, 26 Feb 2019 09:58:00 -0000, Eric Stevens
wrote:

On Mon, 25 Feb 2019 23:12:05 -0000, "Commander Kinsey"
wrote:

On Wed, 20 Feb 2019 22:28:59 -0000, Eric Stevens
wrote:

On Wed, 20 Feb 2019 01:31:48 -0800 (PST), Whisky-dave
wrote:

On Tuesday, 19 February 2019 21:49:04 UTC, Eric Stevens wrote:
On Mon, 18 Feb 2019 02:02:36 -0800 (PST), Whisky-dave
wrote:

On Saturday, 16 February 2019 00:00:21 UTC, Commander
Kinsey wrote:
On Tue, 12 Feb 2019 13:26:52 -0000, Whisky-dave
wrote:



Why would I want the heating on at home when I'm out
most of the day ?
I see you don't know what energy conservation is.

So you don't heat the home when you're at home?

Yes when at home.

I assume you come home at some point.

Yes and like most do have a switch that turns on to heat
the home, switches are things thatr can be off or on and for
teh most part I prefer my heating off from about 8am to
around 4pm during the week because I am not there.

I suppose you leave your car heater and the engine on when
you're not using your car.

I don't turn the heating off when I leave home. I merely
turn down the
thermostat.

So why do you do that ?

See below.

I find I don't save money by turning the heating rigt off
and letting the house cool down.

really most people do and it helps with teh global warming
thing.

Here in the UK we are encouraged to turn down our heating by
just 1C to both save money and the enviroment, but then I
guess if you're a Trump supporter then you don't believe in
such things.


If I do that I've got 30 tons of
house and contents to warm back up again at a time when outside
temperatures are falling.

So you think keeping a house warm when yuo're not there is
more efficient ?

Yes.

My house is hated with a heat pump. If I leave it during the
ay and
turn it on in the evening I am giving it a major load when the
outside
temperatures are approaching coolest. That means the heat pump
runs at
a lower efficiency which means more power has to be used. That
costs
me more. And then there is problem of the icing of the outside
coil.
Deicing heaters come into use and that costs more money also.

Where do you live? I'm in the UK and for some reason heat
pumps haven't taken off here, we're still using gas boilers!
Maybe heat pumps became more popular out in the middle of
nowhere in the USA because piped gas isn't usually available?
I'm shortly going to replace my gas boiler (you call them
furnaces if you're American - we think of a furnace as a huge
commercial thing for burning waste etc) with a heat pump -
mainly because I want to be able to run it in reverse as an air
conditioner.

I live in Auckland. I would be very careful before installing a
conventional heat pump if you expect the temperature to fall much
below 6C for more than a few days in the year.

Most American houses use them without bother. They work well
below 6C. I'll obviously read the specs first. I think some of
them are **** at low temperatures, but not all of them. After
all they work the same as a fridge or freezer, where the cold
side can be -18C or less.

The problem is that the evaporator (outside coil) has to be cooler
than the outside air. Otherwise you would never extract heat from the
outside air. Nominally the temperature difference is only 2C but with
cheaper units the size of the evaporator has bee stinted and it needs
a hiher temperature diffeence to work. The problem is that as the
temperature of the outside air falls moisture starts to condense on
the evaporator and s it falls further the water freezes on the
evaporator. The answer to this is to shut down the heat pump and
switch on heating elements to melt the ice. Once the ice is gone the
heat pump can start up and continue until the next freezing event.

Depending on the heat pump you can run into coil freezing at outside
air temperatures of 6C. However, if the air temperature is less than
0C there should be insignificant water vapour in the air and
continual
freezing is not a problem. So 6C to 0C is the temperature band you
usually have to watch. Bear in mind that heat output is considerably
throttled if the unit has to keep shutting down to thaw out. Also,
the
heating elements will cause power consumption to rise sharply when
you
get into the evaporator freezing zone.

Then explain to me how my freezer can function with the coils
inside the freezer at -18C or below, and constantly frozen up.

1. They will ice up in the normal course of operation and there
usually is a defrost cycle to cope with that.

Only if they get really clogged up. The defrost cycle is only
initiated to make more room so you don't get half the cavity filled
with ice where you want to place food. It cools just fine even
though the coils are covered in ice. In fact older ones didn't auto
defrost at all. You could leave them forever all frozen up and just
get a smaller and smaller food compartment.

Ice is not a good heat conductor and the accumulation of ice does is
to ensure your freezer is at or slightly below 0C whereas the design
temperature is probably -18C. As the ice builds up the temperature
inside the freezer will slowly rise while the power consumptiom of the
freezer increases.

No, the freezer remains at -18C or below just fine. And you'll find ice
is a very good conductor. Place some cold ice from a freezer on your
hand and feel how much heat it pulls from you. It's probably as good as
metal.

Not even close.

Have you tried it? Put a piece of metal in your freezer, and wait till everything has cooled. Now take the metal in one hand and some ice in the other, see if one is different to the other.

I don't know what your background is but it clearly has nothing to do
with physics or engineering.

It's precisely that actually. BSc (Hons) In Physics and Digital Microelectronics.

Granted by whom?

So, did you try my test?

2. They are designed (including sized) to operate in that condition.

Then the heat pumps should be designed in the same way. And they
are, plenty of them can cope with sub zero outdoor temperatures.

That's why I said to be careful as there are also plenty of them which
can't.

Yes, there's always some ****wit designer who makes a device to heat a
house which only works when it's already warm outside. Doh!

I guess you don't get how they work?

Heat pumps are economically sensible when the house temp is set to about
20°C and the outdoor temp is down to about -17°C.

WTF? This discussion included heat pumps not working well below 6C. -17C is a lot below 6C.

The problem area is between 6C and 0C. Above 6c you are unlikely to
get icing on the evaporator because it should not be getting down to
freezing point. Below 0C the air should be dry for practical purposes
and provide little condensate to freeze.

Funny how freezers don't stall when cooling from room temp down through 0-6C.

They don't have a bloody great fan blowing an endless supply of humid
air through them.

It's all about how cold you can make the refrigerant. As long as you
can make it colder than the outside air, then heat flows into it.
--

Regards,

Eric Stevens

In article , Eric Stevens
wrote:

See when you jump in a cold lake, it feels colder than the air? Water
is a good conductor of heat. Ice is just frozen water.

I see you ignored this part.

So that makes ice a good conductor of heat too. How old were you when
you left school?

It's the same substance you fool.

Everything you write increases my doubt that you have any kind of
qualification in physis.

any remaining doubt should be entirely gone after the colour thread
takes its course.

On Sun, 03 Mar 2019 17:34:11 -0000, "Commander Kinsey"
wrote:

On Sun, 03 Mar 2019 09:07:29 -0000, Eric Stevens wrote:

On Sun, 03 Mar 2019 02:13:19 -0000, "Commander Kinsey"
wrote:

On Sun, 03 Mar 2019 02:07:34 -0000, Eric Stevens wrote:

On Sat, 02 Mar 2019 23:57:33 -0000, "Commander Kinsey"
wrote:

On Sat, 02 Mar 2019 18:31:43 -0000, Alan Browne wrote:

On 2019-03-01 17:27, Commander Kinsey wrote:
On Fri, 01 Mar 2019 01:30:18 -0000, Eric Stevens
wrote:

On Wed, 27 Feb 2019 23:48:53 -0000, "Commander Kinsey"
wrote:

On Wed, 27 Feb 2019 22:38:00 -0000, Eric Stevens
wrote:

2. They are designed (including sized) to operate in that condition.

Then the heat pumps should be designed in the same way. And they
are, plenty of them can cope with sub zero outdoor temperatures.

That's why I said to be careful as there are also plenty of them which
can't.

Yes, there's always some ****wit designer who makes a device to heat a
house which only works when it's already warm outside. Doh!

I guess you don't get how they work?

Heat pumps are economically sensible when the house temp is set to about
20°C and the outdoor temp is down to about -17°C.

WTF? This discussion included heat pumps not working well below 6C. -17C is a lot below 6C.

The problem area is between 6C and 0C. Above 6c you are unlikely to
get icing on the evaporator because it should not be getting down to
freezing point. Below 0C the air should be dry for practical purposes
and provide little condensate to freeze.

Funny how freezers don't stall when cooling from room temp down through 0-6C.

It's because they are in a small sealed space which initially contains
only a small amount of water vapor.

I've seen freezers without automatic defrosting that are VERY iced up - as in 4 inches of ice over the coils. They still cool just fine. The only point in scraping the ice off is to increase the space to store the food.

Evidence of slovenly house keeping leading to excessively high
temperatures and accompanying power bills.
--

Regards,

Eric Stevens

Sandman wrote:
Alan Browne wrote:
Commander Kinsey:
I didn't mean it was expensive per unit, I meant you're spending a
lot on heating. My whole heating bill (not just a saving as you
mentioned) in winter is about $30 a MONTH.

1. Canada.
2. My main floor is 1600 square feet. (150 sq. meters).

Sweden here, and 230 m2 house (plus 40 m2 garage). My annual
heating bill is 12,602 SEK ($1,348).
We have district heating though.

US northeast ... probably around 200 m2 (plus garage bays) and a little
higher? ... but our domestic hot water is included in that. Natural Gas.

Is it uncommon with water based district heating in USA and Canada?

Yes, district heating is uncommon, particularly in suburbs.

Alan Browne:
Central furnace. Not as easy to contol individual rooms.
Though the library is kept cool by keeping the door closed and
the heat vent almost closed. A couple other rooms are on that
diet as well.

Commander Kinsey:
Surely you can adjust each individual radiator/blower/whatever you
use? In the UK, our radiators tend to have thermostatic valves.

I don't have radiators. I have a central furnace. So, as I say
above, vents can be adjusted room by room, but it's not something
you do as a daily tune.

You can buy electrically controlled vents, but after looking into
them I passed on it.

I have electrical thermostats on all my radiators, so I can set the
temperature to lower when we're at work, at night, etc.

For heating zones, dramatically fewer in older homes; if you have two,
it’s probably because of an addition (retrofit). In the northern US, it’s
generally forced hot air via furnace, or hot water (usually baseboard)
via a boiler. Radiators (water or steam) are less common, as they
typically weren’t installed after the 1940’s and most home construction
is newer...the US never really adopted the EU’s non-cast iron designs,
at least in residential applications.

Commander Kinsey:
You guys should have twice the insulation we have in the UK, then
your bills would be the same.

There's a limit to ...

Sorry, Google truncating for some reason.


-hh

On Sun, 03 Mar 2019 23:38:48 -0000, "Commander Kinsey"
wrote:

On Sun, 03 Mar 2019 23:16:43 -0000, Eric Stevens wrote:

On Sun, 03 Mar 2019 17:28:34 -0000, "Commander Kinsey"
wrote:

On Sun, 03 Mar 2019 08:59:46 -0000, Eric Stevens wrote:

On Sun, 03 Mar 2019 02:05:44 -0000, "Commander Kinsey"
wrote:

On Sun, 03 Mar 2019 01:58:55 -0000, Eric Stevens wrote:

On Sat, 02 Mar 2019 13:31:25 -0000, "Commander Kinsey"
wrote:

On Sat, 02 Mar 2019 09:12:38 -0000, Eric Stevens wrote:

On Sat, 02 Mar 2019 00:02:59 -0000, "Commander Kinsey"
wrote:

On Fri, 01 Mar 2019 22:57:59 -0000, PeterN wrote:

On 3/1/2019 5:27 PM, Commander Kinsey wrote:

snip


The defroster would be on all the time and simply keep adding heat back
in. Plus ice is a good conductor of heat.

The heat of fusion (heat absorbed on melting of a solid) of water is 334
kilojoules per kilogram. The specific heat of ice at the freezing point
is 2.04 kilojoules per kilogram per degree Celsius. The thermal
conductivity at this temperature is 2.24 watts per metre kelvin.


Pure aluminum has a thermal conductivity of about 235 watts per kelvin
per meter


Brass is 109.....

You may look up the rest.

Well when I hold a piece of ice, it cools my hand pretty quickly. And my freezer which has ice all over the coils works just fine. Clearly you just don't need any more conductivity. Anyway, you should be comparing it with the conductivity of air, because that's what would replace the ice. Funnily enough, air conducts very badly, which is why placing your bare hand outside in winter in the air isn't that cold compared with picking up ice.

Air transfers heat in a freezer by convection. As you say, it is not a
good conductor.

Conduction is way better than convection for any material.

Nonsense.

How ignorant are you? Place your hand outside in the air at 0C. Now touch something. Which feels colder? Conduction passes WAY more heat than convection. Why do you think it's good to have gaps in double brick walls, double glazing etc? Why do you think we don't have solid thick glass or a triple brick wall with no gap?

I am a damned sight less ignorant than you have repeatedly
demonstrated yourself to be. Does your knowledge of thermodynamics
extend beyond what you can touch?

Personal experience always beats reading things on google.

So much for your claimed degree.

Please try to make your replies have at least something to do with the rest of the thread.

My comment is directed at your credibility.

Double brick walls were originally constructed to form a water
barrier. There is a critical gap for double glazing. Too small and
heat can conduct across too easily. Too large a gap and circulation
cells can form giving rise to heat conduction by convection.

Actually anywhere from about 1 to 4 inghes gap is the same R of 4.
--

Regards,

Eric Stevens

On Sun, 03 Mar 2019 20:51:16 -0500, nospam
wrote:

In article , Eric Stevens
wrote:

See when you jump in a cold lake, it feels colder than the air? Water
is a good conductor of heat. Ice is just frozen water.

I see you ignored this part.

So that makes ice a good conductor of heat too. How old were you when
you left school?

It's the same substance you fool.

Everything you write increases my doubt that you have any kind of
qualification in physis.

any remaining doubt should be entirely gone after the colour thread
takes its course.

For a phsicist of any kind he seems to be extraordinarily ignorant of
the properties of materials.
--

Regards,

Eric Stevens

In article , Eric Stevens
wrote:

See when you jump in a cold lake, it feels colder than the air?
Water is a good conductor of heat. Ice is just frozen water.

I see you ignored this part.

So that makes ice a good conductor of heat too. How old were you when
you left school?

It's the same substance you fool.

Everything you write increases my doubt that you have any kind of
qualification in physis.

any remaining doubt should be entirely gone after the colour thread
takes its course.

For a phsicist of any kind he seems to be extraordinarily ignorant

oh, you ain't seen nuthin' yet.

of
the properties of materials.

those words are not needed.