A/C box...

[RichD]

There\'s a new window box air conditioner that\'s shaking
up a stodgy industry. The story described its gizzards
as a \"variable speed inverting compressor\".

Your explication, please ...

--
Rich

 

[RichD]

On June 23, RichD wrote:

There\'s a new window box air conditioner that\'s shaking
up a stodgy industry. The story described its gizzards
as a \"variable speed inverting compressor\".

\"inverter compressor\"

 

[Lasse Langwadt Christensen]

fredag den 23. juni 2023 kl. 22.09.05 UTC+2 skrev RichD:

There\'s a new window box air conditioner that\'s shaking
up a stodgy industry. The story described its gizzards
as a \"variable speed inverting compressor\".

Your explication, please ...

instead of running the compressor at a fixed high speed set by the mains frequency
it uses an inverter to generate a variable frequency 3 phase AC to run the compressor
at the just right speed needed for the load

 

[Don Y]

On 6/23/2023 1:21 PM, Lasse Langwadt Christensen wrote:

fredag den 23. juni 2023 kl. 22.09.05 UTC+2 skrev RichD:
There\'s a new window box air conditioner that\'s shaking
up a stodgy industry. The story described its gizzards
as a \"variable speed inverting compressor\".

Your explication, please ...

instead of running the compressor at a fixed high speed set by the mains frequency
it uses an inverter to generate a variable frequency 3 phase AC to run the compressor
at the just right speed needed for the load

Exactly. Some automobiles similarly control the speed of the
compressor (instead of just bang-on, bang-off) in an effort
to improve efficiency and comfort.

[Air conditioning being one of the biggest loads in a vehicle]

 

[Lasse Langwadt Christensen]

fredag den 23. juni 2023 kl. 22.50.09 UTC+2 skrev Don Y:

On 6/23/2023 1:21 PM, Lasse Langwadt Christensen wrote:
fredag den 23. juni 2023 kl. 22.09.05 UTC+2 skrev RichD:
There\'s a new window box air conditioner that\'s shaking
up a stodgy industry. The story described its gizzards
as a \"variable speed inverting compressor\".

Your explication, please ...

instead of running the compressor at a fixed high speed set by the mains frequency
it uses an inverter to generate a variable frequency 3 phase AC to run the compressor
at the just right speed needed for the load
Exactly. Some automobiles similarly control the speed of the
compressor (instead of just bang-on, bang-off) in an effort
to improve efficiency and comfort.

at one point there was talk about switching cars to 42V with a big combined starter generator
that way all the accessories could be electrical and mounted where convenient instead of
where it could be driven by a belt

for AC that would also enable variable speed and a hermetically sealed compressor with out
fancy seals on an input shaft that have to hold high side refrigerant pressure

 

[Jasen Betts]

On 2023-06-23, RichD <r_delaney2001@yahoo.com> wrote:

There\'s a new window box air conditioner that\'s shaking
up a stodgy industry. The story described its gizzards
as a \"variable speed inverting compressor\".

Your explication, please ...

The compressor is driven by a VFD
(which they call a variable speed inverter)

This is not new Air Con technology, but may be new to
through-wall units.

--
Jasen.
🇺🇦 Слава Україні

 

[RichD]

On June 23, Don Y wrote:

There\'s a new window box air conditioner that\'s shaking
up a stodgy industry. The story described its gizzards
as a \"variable speed inverting compressor\".

instead of running the compressor at a fixed high speed set by the mains frequency
it uses an inverter to generate a variable frequency 3 phase AC to run the compressor
at the just right speed needed for the load

Exactly. Some automobiles similarly control the speed of the
compressor (instead of just bang-on, bang-off) in an effort
to improve efficiency and comfort.

Switchers use bang/bang for greater efficiency vs. linear.

--
Rich

 

[Don Y]

On 6/23/2023 2:23 PM, Lasse Langwadt Christensen wrote:

fredag den 23. juni 2023 kl. 22.50.09 UTC+2 skrev Don Y:
On 6/23/2023 1:21 PM, Lasse Langwadt Christensen wrote:
fredag den 23. juni 2023 kl. 22.09.05 UTC+2 skrev RichD:
There\'s a new window box air conditioner that\'s shaking
up a stodgy industry. The story described its gizzards
as a \"variable speed inverting compressor\".

Your explication, please ...

instead of running the compressor at a fixed high speed set by the mains frequency
it uses an inverter to generate a variable frequency 3 phase AC to run the compressor
at the just right speed needed for the load
Exactly. Some automobiles similarly control the speed of the
compressor (instead of just bang-on, bang-off) in an effort
to improve efficiency and comfort.

at one point there was talk about switching cars to 42V with a big combined starter generator
that way all the accessories could be electrical and mounted where convenient instead of
where it could be driven by a belt

There have been some changes in that direction. E.g., power steering assist
is now electric in many ICEs.

for AC that would also enable variable speed and a hermetically sealed compressor with out
fancy seals on an input shaft that have to hold high side refrigerant pressure

\"Refrigeration\" is supposedly the biggest energy problem to address (folks
without cards still need/want ACbrrr -- think the half of the world population
that is represented by India + China).

But, there are lots of \"tricks\" that can be applied to reduce the energy
that goes to this task.

E.g., cooling the entire interior space in a vehicle is ~4KW. Yet, ~70+% of
vehicles are single occupant -- needing ~650W to keep JUST that occupant
comfortable (by carefully controlling the cooling).

Here, for example, speed limits in town are 45MPH (which *means* 55MPH).
Yet, average vehicle speed (confirmed by querying friends to watch their
trip computers) is about 20MPH. So, HALF of the travel time is spent
SITTING STILL.

Even if you can shut off ALL of the power required for locomotion, you
still need to keep the occupant(s) \"comfortable\". Naively trying to cool the
entire interior of the vehicle would be a horrendous waste of energy.

If, instead, you can direct cooling to the DETECTED occupants and to
the parts of their bodies that will be most sensitive to said cooling,
then you can reduce the energy that you would otherwise naively dump
into the vehicle\'s interior.

And, if you can make for a more uniform experience (e.g., not cold, cool,
cold, cool, cold, cool...) then the occupants will be more likely to
tolerate a higher temperature setting (if you control based on temperature)

[The same, of course, is true in edifices. Why cool an entire space
if only parts of it are used by \"temperature sensitive entities\"?]

 

[Phil Hobbs]

On 2023-06-23 16:21, Lasse Langwadt Christensen wrote:

fredag den 23. juni 2023 kl. 22.09.05 UTC+2 skrev RichD:
There\'s a new window box air conditioner that\'s shaking
up a stodgy industry. The story described its gizzards
as a \"variable speed inverting compressor\".

Your explication, please ...

instead of running the compressor at a fixed high speed set by the mains frequency
it uses an inverter to generate a variable frequency 3 phase AC to run the compressor
at the just right speed needed for the load

Oh, great, now we\'ll be completely inundated with crappy unfiltered
Chinese variable-frequency drives. Talk about an EMI nightmare.

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.net
http://hobbs-eo.com

 

[John Larkin]

On Fri, 23 Jun 2023 19:09:27 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

On 2023-06-23 16:21, Lasse Langwadt Christensen wrote:
fredag den 23. juni 2023 kl. 22.09.05 UTC+2 skrev RichD:
There\'s a new window box air conditioner that\'s shaking
up a stodgy industry. The story described its gizzards
as a \"variable speed inverting compressor\".

Your explication, please ...

instead of running the compressor at a fixed high speed set by the mains frequency
it uses an inverter to generate a variable frequency 3 phase AC to run the compressor
at the just right speed needed for the load


Oh, great, now we\'ll be completely inundated with crappy unfiltered
Chinese variable-frequency drives. Talk about an EMI nightmare.

Cheers

Phil Hobbs

Quit your bitchin\'. They will all have UL and FCC and CE stickers.

 

[Ricky]

On Friday, June 23, 2023 at 6:38:48 PM UTC-4, Don Y wrote:

On 6/23/2023 2:23 PM, Lasse Langwadt Christensen wrote:
fredag den 23. juni 2023 kl. 22.50.09 UTC+2 skrev Don Y:
On 6/23/2023 1:21 PM, Lasse Langwadt Christensen wrote:
fredag den 23. juni 2023 kl. 22.09.05 UTC+2 skrev RichD:
There\'s a new window box air conditioner that\'s shaking
up a stodgy industry. The story described its gizzards
as a \"variable speed inverting compressor\".

Your explication, please ...

instead of running the compressor at a fixed high speed set by the mains frequency
it uses an inverter to generate a variable frequency 3 phase AC to run the compressor
at the just right speed needed for the load
Exactly. Some automobiles similarly control the speed of the
compressor (instead of just bang-on, bang-off) in an effort
to improve efficiency and comfort.

at one point there was talk about switching cars to 42V with a big combined starter generator
that way all the accessories could be electrical and mounted where convenient instead of
where it could be driven by a belt
There have been some changes in that direction. E.g., power steering assist
is now electric in many ICEs.
for AC that would also enable variable speed and a hermetically sealed compressor with out
fancy seals on an input shaft that have to hold high side refrigerant pressure
\"Refrigeration\" is supposedly the biggest energy problem to address (folks
without cards still need/want ACbrrr -- think the half of the world population
that is represented by India + China).

But, there are lots of \"tricks\" that can be applied to reduce the energy
that goes to this task.

E.g., cooling the entire interior space in a vehicle is ~4KW. Yet, ~70+% of
vehicles are single occupant -- needing ~650W to keep JUST that occupant
comfortable (by carefully controlling the cooling).

Here, for example, speed limits in town are 45MPH (which *means* 55MPH).
Yet, average vehicle speed (confirmed by querying friends to watch their
trip computers) is about 20MPH. So, HALF of the travel time is spent
SITTING STILL.

Even if you can shut off ALL of the power required for locomotion, you
still need to keep the occupant(s) \"comfortable\". Naively trying to cool the
entire interior of the vehicle would be a horrendous waste of energy.

If, instead, you can direct cooling to the DETECTED occupants and to
the parts of their bodies that will be most sensitive to said cooling,
then you can reduce the energy that you would otherwise naively dump
into the vehicle\'s interior.

And, if you can make for a more uniform experience (e.g., not cold, cool,
cold, cool, cold, cool...) then the occupants will be more likely to
tolerate a higher temperature setting (if you control based on temperature)

[The same, of course, is true in edifices. Why cool an entire space
if only parts of it are used by \"temperature sensitive entities\"?]

The idea of directed cooling is not very functional. My car is rather cavernous, as opposed to a smallish cab pickup truck I used to drive. I notice when going around turns, that the air does not fully turn with the car and I am suddenly sitting in hot/cold air, when I was sitting in cool/warm air.. Cars of any size will have this effect that mitigate the effectiveness of trying to just cool the occupants.

--

Rick C.

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

 

[RichD]

On June 23, Don Y wrote:

for AC that would also enable variable speed and a hermetically sealed compressor
without fancy seals on an input shaft that have to hold high side refrigerant pressure

But, there are lots of \"tricks\" that can be applied to reduce the energy
that goes to this task.
E.g., cooling the entire interior space in a vehicle is ~4KW. Yet, ~70+% of
vehicles are single occupant -- needing ~650W to keep JUST that occupant
comfortable (by carefully controlling the cooling).

There must be an obvious A/C energy saving in EV.

If, instead, you can direct cooling to the DETECTED occupants and to
the parts of their bodies that will be most sensitive to said cooling,

They have heated seats, so....

This raises an interesting question of human biology and
perception. A/C is primarily an issue of perception, comfort.
Then, which surfaces of the body are most sensitive to
temperature? I don\'t know of any research on this. But it might
offer large energy efficiencies for cooling.

--
Rich

 

[ke...@kjwdesigns.com]

On Friday, 23 June 2023 at 17:26:42 UTC-7, Ricky wrote:
....

The idea of directed cooling is not very functional. My car is rather cavernous, as opposed to a smallish cab pickup truck I used to drive. I notice when going around turns, that the air does not fully turn with the car and I am suddenly sitting in hot/cold air, when I was sitting in cool/warm air.. Cars of any size will have this effect that mitigate the effectiveness of trying to just cool the occupants.

....

My Prius has that feature.

A control button allows conditioning either for just the driver or all occupants.

I don\'t know how much it reduces energy consumption but I\'ve never noticed any issue with it.

The Prius is a hybrid so the A/C compressor is powered electrically with an inverter from the traction battery. I don\'t know over what speed range it operates.

kw

 

[Ricky]

On Saturday, June 24, 2023 at 3:50:09 PM UTC-4, RichD wrote:

On June 23, Don Y wrote:
for AC that would also enable variable speed and a hermetically sealed compressor
without fancy seals on an input shaft that have to hold high side refrigerant pressure

But, there are lots of \"tricks\" that can be applied to reduce the energy
that goes to this task.
E.g., cooling the entire interior space in a vehicle is ~4KW. Yet, ~70+% of
vehicles are single occupant -- needing ~650W to keep JUST that occupant
comfortable (by carefully controlling the cooling).
There must be an obvious A/C energy saving in EV.

Yes, there is. In an ICE, all power ultimately comes from the gasoline, converted by the engine to mechanical power. This is VERY inefficient, around 25 to 30%, typically. In the BEV, the electricity runs a compressor thorough an electric motor, all with very good efficiency.

It is the efficiency of converting electrical power to other forms, that reduces the pollution caused by BEVs, even when that electricity is generated from fossil fuels.

If, instead, you can direct cooling to the DETECTED occupants and to
the parts of their bodies that will be most sensitive to said cooling,
They have heated seats, so....

And in some cars, cooled seats.

This raises an interesting question of human biology and
perception. A/C is primarily an issue of perception, comfort.
Then, which surfaces of the body are most sensitive to
temperature? I don\'t know of any research on this. But it might
offer large energy efficiencies for cooling.

I don\'t think it works that way. If find in my model X, in the winter, my left foot tends to be cold and there\'s nothing I can do to mitigate this. I never had it in my T100, where tons of heat was available, or any other car that I can recall.

One thing about the Teslas that I think shows the difference between a startup and a long term automaker, is the lack of attention to details. The poor circulation of warm air by the floor, is one of those. The electric drive train is nothing short of amazing. But the rest of the car is... a car.

--

Rick C.

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

 

[Fred Bloggs]

On Friday, June 23, 2023 at 4:09:05 PM UTC-4, RichD wrote:

There\'s a new window box air conditioner that\'s shaking
up a stodgy industry. The story described its gizzards
as a \"variable speed inverting compressor\".

Your explication, please ...

A bunch of marketing talk- similar to inverter generators. The compressor is not an inverter. It\'s powered by an inverter. And that is the kind of inverter every EE knows to be a DC to AC conversion system

They should say inverter powered variable speed compressor. The meaning of that should be perfectly clear. The advantage is a profound improvement in efficiency. The old technology was lucky to get SEER 8, I would expect at least SEER 16 from the variable speed -dunno for sure ( actually no idea) *.. SEER being seasonal BTU cooling power per Watt-hours dissipated operating it.

*Quick search says that\'s about right.

Every bit of web based explanation for SEER is totally moronic. You have to go to a research paper to find a formula.

https://www.sciencedirect.com/topics/engineering/seasonal-energy-efficiency-ratio

--
Rich

 

[Don Y]

On 6/24/2023 12:50 PM, RichD wrote:

On June 23, Don Y wrote:
for AC that would also enable variable speed and a hermetically sealed compressor
without fancy seals on an input shaft that have to hold high side refrigerant pressure

But, there are lots of \"tricks\" that can be applied to reduce the energy
that goes to this task.
E.g., cooling the entire interior space in a vehicle is ~4KW. Yet, ~70+% of
vehicles are single occupant -- needing ~650W to keep JUST that occupant
comfortable (by carefully controlling the cooling).

There must be an obvious A/C energy saving in EV.

There is a lot of research into it because, unlike in an ICE, you
can\'t just add a gallon of gas to the tank to power the ACbrrr.

Or, fuel up if you\'ve been sitting in traffic and burning
more energy than you\'d expected.

(I can recall a four hour spell in traffic when I was returning
home for the holidays while at school)

If, instead, you can direct cooling to the DETECTED occupants and to
the parts of their bodies that will be most sensitive to said cooling,

They have heated seats, so....

There are \"cooled\" seats as well.

And, there has been research into putting air *at*
the driver\'s face (i.e., from the headrest), detecting
number (and RACE!) of occupants, varying the rate of flow
from *shaped* nozzles, etc.

This raises an interesting question of human biology and
perception. A/C is primarily an issue of perception, comfort.

Exactly. The human closes the loop, not the vehicle/HVAC.
Unless you can make the human FEEL like he is comfortable,
he will likely push the controls past the point where it
might otherwise be a \"comfort-able\" setting into one
that is just incredibly inefficient.

Conditioned air that is emitted from vents for other
occupants that are not *present* in the vehicle is (largely)
wasted energy. HVAC to the rear seats when they are
unoccupied 70++% of the time is waste. Likewise for the
passenger seat (most travel is single occupant)

Most cars have MANUAL controls for air flow (e.g., to close
off vents for the areas of the vehicle that aren\'t occupied).
But, these require manual control and attention. (e.g.,
the back seat in our vehicle is closed as there are seldom
additional occupants, there -- and, if needed, could those
passengers could easily be told to open the vents)

It\'s also possible to set different temperatures in
different occupancy zones. But, again, too much of
this relies on the driver/occupants to actively
engage. With the majority of trips being single
occupant, how often do you think the driver makes
an effort to shut the unneeded vents/controls??

\"Open loop\" (or *nearly* open loop) controls are grossly
inefficient. Expect to see big changes, there. Esp
in EVs where surplus energy isn\'t easily available.

(I can sit in my car for more than a day, idling,
with the ACbrrr running and not run out of fuel)

Then, which surfaces of the body are most sensitive to
temperature? I don\'t know of any research on this. But it might
offer large energy efficiencies for cooling.

The back, chest and ass tend to be most \"sensitive\" to
thermal changes/discomfort. The head and other limbs
slightly less so. The feet and hands, least.

The back of the neck is the most sensitive.

Additionally, getting conditioned air to the \"breathing space\"
yields a disproportionately larger benefit than trying to
envelope the body with a comparable amount. A cool breeze
on your face feels more comforting than one aimed at your chest!

The \"age\" of the conditioned air also plays a role in comfort;
air that has to travel, e.g., the back seat is less effective
than air \"used\" closer to the evaporator. I.e., we may see
more/smaller evaporators in the future to bring the air
*to* the load, better (just as we now see refrigerators
with multiple evaporators). Being able to shut down an
evaporator results in energy savings as that cooling load is
elided.