On Tue, 07 Feb 2023 07:02:14 GMT, Jan Panteltje <alien@comet.invalid>
wrote:
>On a sunny day (Mon, 6 Feb 2023 09:01:19 -0500) it happened Phil Hobbs
><pcdhSpamMeSenseless@electrooptical.net> wrote in
><edfbc261-d373-0b06-2b41-145ec2fa273f@electrooptical.net>:
>
>>Right, which is where the gasoline generator comes in.
>
>Solar is cheaper
What about a few weeks with no untilties and snow and below 0 deg F?
"On a sunny day..." is, I assume, an attempt at irony.
Reply by Don Y●February 7, 20232023-02-07
On 2/7/2023 2:00 AM, James wrote:
> On 06/02/2023 15:12, Don Y wrote:
>
>>>> why not use a microwave oven for all
>>>> food prep?
>>>
>>> Because it is inefficient. (Mine is; present your results.)
>>
>> IME, I've never heard anyone cite the ENERGY EFFICIENCY of their
>> meal prep method/equipment.
>
> Evidentially you have missed all the air fryer debates and much of the rest
> about the price of electricity and gas.
Or, they've simply not existed on this side of the pond. We have
a (shamefully) much more cavalier attitude towards energy, here.
At this moment, there are three computers running, here. A dozen more
are drawing their allowed 1W while "off", awaiting a pushbutton start.
The same number of monitors "sleeping", waiting for signal to wake up.
The 3 TVs all sit waiting for a burst of Ir to bring them to life.
Ditto with the two HiFis.
The stove and microwave are dutifully telling a sleeping household
the current time of day (night). As is another clock in the living
room and one at each bedside.
Twelve UPSs are each displaying their current loads and efficiencies.
Garage door opener is waiting for an RF signal to open the door -- and
monitoring the area by the door for obstruction/activity despite the
door being closed.
I can hear the transformer in the furnace humming as it waits to
warm the cool night air.
And, there are 2200W of XMAS lights keeping the chill off the
citrus trees just in case it gets much below freezing. (My
neighbor has probably half that much as his trees are much
smaller)
Do you think I worry that the microwave oven is "wasting" a watt
while "off"? Do you think any of my neighbors have unplugged their
microwaves, garage door openers, stoves, furnaces, computers,
cell phone chargers, etc. to eliminate these power vampires?
>> If I was concerned with the energy efficiency of the meal, I would
>> have taken the sauce out of the freezer yesterday and let it thaw
>> in the refrigerator -- instead of "forcing" the issue in the microwave!
>
> I do.
Good for you! (really) I worry about how much water I use as water is
a scarcity, here. But, I can buy pretty much all the power that I want!
>>> Previously when I tested the induction hob it was close to the
>>> kettle's efficiency, like 93% vs 87% but I heated 1kg of water then,
>>> the kettle has a minimum of 0.5kgs so I did not test this time.
>>
>> Wow, you must be the life of the party -- not! :>
>
> No. I am a thermo-fluids engineer writing in sci.* news group but not for much
> longer if your reply is the standard.
My replies -- then and now -- are honest. You might want to reread them
to see what they say about how many/most folks approach things like cooking
choices, here.
If you aren't happy with them, that's your choice.
Reply by James●February 7, 20232023-02-07
On 06/02/2023 15:12, Don Y wrote:
>>> why not use a microwave oven for all
>>> food prep?
>>
>> Because it is inefficient. (Mine is; present your results.)
>
> IME, I've never heard anyone cite the ENERGY EFFICIENCY of their
> meal prep method/equipment.
Evidentially you have missed all the air fryer debates and much of the
rest about the price of electricity and gas.
> If I was concerned with the energy efficiency of the meal, I would
> have taken the sauce out of the freezer yesterday and let it thaw
> in the refrigerator -- instead of "forcing" the issue in the microwave!
I do.
>> Previously when I tested the induction hob it was close to the
>> kettle's efficiency, like 93% vs 87% but I heated 1kg of water then,
>> the kettle has a minimum of 0.5kgs so I did not test this time.
>
> Wow, you must be the life of the party -- not! :>
No. I am a thermo-fluids engineer writing in sci.* news group but not
for much longer if your reply is the standard.
Reply by Phil Hobbs●February 7, 20232023-02-07
On 2023-02-07 02:02, Jan Panteltje wrote:
> On a sunny day (Mon, 6 Feb 2023 09:01:19 -0500) it happened Phil Hobbs
> <pcdhSpamMeSenseless@electrooptical.net> wrote in
> <edfbc261-d373-0b06-2b41-145ec2fa273f@electrooptical.net>:
>
>> Right, which is where the gasoline generator comes in.
>
> Solar is cheaper
>
Yer cracked, but we knew that. ;)
Cheers
Phil Hobbs
--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510
http://electrooptical.nethttp://hobbs-eo.com
Reply by Jan Panteltje●February 7, 20232023-02-07
On a sunny day (Mon, 6 Feb 2023 09:01:19 -0500) it happened Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote in
<edfbc261-d373-0b06-2b41-145ec2fa273f@electrooptical.net>:
>Right, which is where the gasoline generator comes in.
Solar is cheaper
Reply by Hul Tytus●February 6, 20232023-02-06
Don - there exists an equation whereby the temperature of a surface
of a given area subjected to a given wattage is returned. The surrounding
air is assumed free standing.
something like this: temp = 300 * watts / area
You might look in web for such a creature.
Hul
Don Y <blockedofcourse@foo.invalid> wrote:
> How do I determine the power handling (thermal) capabilities
> and impact on mechanical strength at specific power
> levels/temperatures?
Reply by John Larkin●February 6, 20232023-02-06
On Sat, 4 Feb 2023 11:31:01 -0700, Don Y <blockedofcourse@foo.invalid>
wrote:
>On 2/3/2023 4:32 PM, Clive Arthur wrote:
>> On 03/02/2023 20:21, legg wrote:
>>
>> <snip>
>>
>>> Glass cooktops are a joke, provoking the worst aspects
>>> of the electric stove top cooking w/r to delays, heat tranfer
>>> and loss.
>>>
>>> RL
>>
>> But induction is the bee's knees.� I'd never go back to gas, and the only thing
>> I miss is using the flame to char peppers.
>
>We didn't like the induction cooktops when we were shopping.
>It seems their (practical) claim to fame is how quickly they
>heat up. But, aside from bringing a pot of water to boil,
>they're not going to significantly change the overall cooking
>time.
>
>Pancakes, yesterday. Roughly two minutes per skillet-full.
>I suspect I could cook on a higher heat setting but will
>that cut the time down to... 90 seconds? And, what would
>the consequences be for the flapjacks? Will the sausages
>be ready?
>
>If I bring a pot of water to temperature instantly (!), will
>that meaningfully change the amount of time it takes for the
>contents to cook? (why not use a microwave oven for all
>food prep?)
>
>I routinely (4-6 wks) make a 16 qt pot of red sauce. It
>takes ~12 hours to cook -- so the flavors mellow. The
>biggest problem is making sure the pot doesn't get *too*
>hot (the thermal gradient through a foot of sauce is pretty
>high) and burn to the bottom of the pan. I can't use a gas
>stove for this (can't get the flame low enough as it always
>leaves a small hot spot). And, electric is a juggling act
>to see how close to "OFF" you can set the control!
A FOM for a big steam boiler is "turndown ratio." Our newish Bosch
5-burner stovetop is fabulous.
To avoid hot spots, use a thick cast aluminum pot, like the Curtis
Stone ones.
Reply by Don Y●February 6, 20232023-02-06
On 2/6/2023 2:43 AM, James wrote:
> On 04/02/2023 18:31, Don Y wrote:
>> why not use a microwave oven for all
>> food prep?
>
> Because it is inefficient. (Mine is; present your results.)
IME, I've never heard anyone cite the ENERGY EFFICIENCY of their
meal prep method/equipment. They do, however, tend to be concerned
with the TIME efficiency (note the portion of my quote that you elided):
If I bring a pot of water to temperature instantly (!), will
that meaningfully change the amount of time it takes for the
contents to cook? (why not use a microwave oven for all
food prep?)
I made pasta for breakfast. As I hadn't planned on this, previously,
I had to fetch a container of bolognese sauce from the freezer. I
could coax the block of sauce into a saucepan and heat it on the stovetop
as an expedited means of "defrosting" -- and resign myself to having
to clean another saucepan, afterwards (time). Or, I can put it in the
microwave for a few minutes -- while I put the pot of water (for the pasta)
on the stovetop.
Forty minutes later, I'd eaten the meal and cleaned the plate, silver
and saucepot. And, the pasta spent 20 of those minutes "cooking".
If I was concerned with the energy efficiency of the meal, I would
have taken the sauce out of the freezer yesterday and let it thaw
in the refrigerator -- instead of "forcing" the issue in the microwave!
> Heating 0.25 kgs of water from 18 to boiling, Microwave: 265 kJ of electricity,
> induction hob: 118kJ. Ratio: 0.45. The energy of the water alone is 86kJ but
> inefficiency includes heating the water container, Pyrex vs steel. This was an
> approximate but real test and not a measure of the underlying energy transfer.
>
> Previously when I tested the induction hob it was close to the kettle's
> efficiency, like 93% vs 87% but I heated 1kg of water then, the kettle has a
> minimum of 0.5kgs so I did not test this time.
Wow, you must be the life of the party -- not! :>
> I haven't added the 2W all the time the MW plugged is in, the 28W while its
> door is open [light] nor the 35W it uses afterwards cooling itself.
Your stove/oven doesn't use ANY electricity while it is HARD-WIRED
to the mains? No clock? Standby power for the MCU in the controller?
>> I can't use a gas
>> stove for this (can't get the flame low enough as it always
>> leaves a small hot spot). And, electric is a juggling act
>> to see how close to "OFF" you can set the control!
>
> A case for induction. I have 9 settings plus boost and a "keep hot" setting.
> There are big and small hotplates so this extends the range of settings. I
> have no problem simmering, in fact the low numbers are so good I can cook
> casseroles on the hob without any sticking or burning - forget putting the iron
> pot in the oven. To melt chocolate it is recommended to use a bowl in saucepan
> of boiling water - forget that, just put chocolate directly in a saucepan and
> set the induction hob to 1 or 2. The low simmering saves money because I can
> cook without steam issuing from the lids.
I've not used a double-boiler since the last time I used gas
(40+ years ago). I routinely melt chocolate (SWMBO enjoys
almonds covered in dark chocolate and rolled in cocoa powder)
on the stovetop. The chocolate doesn't boil or burn on
the lowest heat setting.
We make rice weekly using the lowest setting of the burner
to SLOWLY cook the grains -- while we're preparing the rest
of the meal on the other burners.
I routinely use the microwave oven to "soften" butter (the
days of heated butter compartments in refrigerators seem
long gone). Then, have the refrigerator resolidify it
when returned there -- trading my time for energy inefficiency
(I have no desire to wait for the butter to come to room
temperature to soften)
You'll find that cooking a heavy, thick sauce leads to a much
larger thermal gradient from the 12 inches of material that
separate the burner surface from the top of the contents.
The lower surface will be "boiling" (evidenced by bubbles
percolating up through the sauce and "splattering") while
the upper layers remain at room temperature.
There is no way the cooktop can compensate for this; you have
to routinely "ladle" the contents from the bottom of the pot
up to the top to keep those on the bottom from burning to the pan
and move the cooler material from the top down to the heat source.
However, this isn't a wasted effort as it gives you a chance to
shake the condensate from the underside of the lid, thus
thickening the sauce.
Heat sources that aren't well distributed (like a gas flame, on
"low") only exacerbate this due to the thermal gradient
HORIZONTALLY within the pot (a small diameter heat source isn't
going to effectively heat the outer edges of a 12" wide pot).
But, electric lets you select a large diameter heating surface
AND low power; turn the control on until the "burner on" light
JUST illuminates. At this power level, water *won't* boil
(but the sauce will -- due to the insulating effect of the
material above)
Reply by John Larkin●February 6, 20232023-02-06
On Mon, 6 Feb 2023 09:01:19 -0500, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:
>On 2023-02-06 01:30, Jan Panteltje wrote:
>> On a sunny day (Sun, 5 Feb 2023 14:46:38 -0500) it happened Phil Hobbs
>> <pcdhSpamMeSenseless@electrooptical.net> wrote in
>> <99d86a08-66dc-7e57-6e4a-6ba1f1bc9d5d@electrooptical.net>:
>>
>>> On 2023-02-04 01:21, Jan Panteltje wrote:
>>>> On a sunny day (Fri, 3 Feb 2023 23:32:41 +0000) it happened Clive Arthur
>>>> <clive@nowaytoday.co.uk> wrote in <trk5iq$1l09j$1@dont-email.me>:
>>>>
>>>>> On 03/02/2023 20:21, legg wrote:
>>>>>
>>>>> <snip>
>>>>>
>>>>>> Glass cooktops are a joke, provoking the worst aspects
>>>>>> of the electric stove top cooking w/r to delays, heat tranfer
>>>>>> and loss.
>>>>>>
>>>>>> RL
>>>>>
>>>>> But induction is the bee's knees. I'd never go back to gas, and the
>>>>> only thing I miss is using the flame to char peppers.
>>>>
>>>> It depends:
>>>> I have one induction cookplate that gives me a big headache when using it.
>>>> Probably RF radiation, so I no longer use it.
>>>> My Chinese induction experiments work fine though:
>>>> http://panteltje.com/pub/induction_heater_quadcopter_power_dummy_load_test_IMG_6102.JPG
>>>> http://panteltje.com/pub/melting_solder_in_an_metal_olive_bottle_cap_IMG_5191.JPG
>>>> http://panteltje.com/pub/carbon_crucible_zero_load_IMG_5429.JPG
>>>>
>>>
>>> You folks don't have real weather, though.
>>
>> Oh you must be kidding
>> I remember going for a job interview by bus when it was -40 C here,
>> Got of the bus at the wrong stop and had to walk miles to the company
>> with just a plastic coat and jeans...
>> Luckily met some old schoolmates there and warmed up in a local restaurant
>> Got the job
>> When I got back in Amsterdam in my flat at the 9th floor, the central heating no longer worked..
>> Luckily had an electric heater.
>> (The flat next to it was the one that a Boeing 747 cargo plane flew into, 4 years after I moved to the North here,
>> but that was not weather related).
>> We also many years ago had massive flooding from storms in the south west...
>> Dams were build after that,
>>
>>
>>> Round here we get the
>>> occasional storm that would make an Orkneyman or Shetlander shudder.
>>> Gas heat, gas cooktop, gasoline generator, Good Medicine.
>>
>> I have gas central heating here.
>> For that to work you need electricity too.
>
>Right, which is where the gasoline generator comes in.
>
>Cheers
>
>Phil Hobbs
Our old Victorian had a "gravity heater", giant pilot light,
convection only. It was probably inefficient, but gas used to be
cheap.