Super Simple Solar Energy

On Tuesday, 5 November 2019 06:07:55 UTC, Bill Sloman wrote:

On Tuesday, November 5, 2019 at 3:43:43 PM UTC+11, tabby wrote:
On Monday, 4 November 2019 14:54:48 UTC, Winfield Hill wrote:
John S wrote...
tabbypurr wrote:

And desiccant wheel dehumidifiers work just fine.

And what do you do with the desiccant when it is
saturated with water?

Do they become humidifiers, when (if) the air
otherwise becomes dry again?

The wheel slowly rotates, drying room air on one side, and drying the desiccant on the other. Pass hot air through it, which then circulates around a metal compartment. The metal is cooled by the room air, forming condensation thus removing damp from the compartment. Condensate drips into a container or down a pipe. These machines are ideal for unheated spaces, where compressor types become near useless.

I wonder why NT thinks that?

because it's correct

> Passing hot air over the drying half of the wheel and letting the room air cool the desiccant enough to let it work again as a desiccant is heating the space being dried.

you don't say

> The thermodynamics aren't going to be impressive.

they're quite practical.

> Heat pumps are designed to be thermodynamically efficient,

some refrigeration dehumidifiers are, some clearly aren't

> and they can certainly take water out of the air in unheated spaces - there isn't much there to take out when the air is cold, but that doesn't stop them taking out what's there to be extracted.

so another topic you don't know enough about to avoid bsing.

For always warm areas the compressor type gives better energy efficiency - or can if well designed.

NT clearly hasn't got a clue about thermodynamics or vapour pressures. Thermodynamics is notoriously hard to teach, and NT is rather too willing to stop thinking when he fixes on a delusion that he likes.

thanks for wasting everyone's time. Again.

 

[dcaster@krl.org]

On Monday, November 4, 2019 at 8:26:15 PM UTC-5, Bill Sloman wrote:

I've never seen one. What sort of volume are they used to desiccate?
"
A hundred million cubic meters and up.

Dan

--
Bill Sloman, Sydney

 

[Jeroen Belleman]

I (Jeroen) wrote:

klaus.kragelund@gmail.com wrote:

[Snip!]


The accuracy of 0.3% is cheap, just takes some thought. As I wrote, much lower than 1 USD

Increasing efficiency of the converter is costly, cannot be compared

Cheers

Klaus

I don't understand that circuit very well. [...]

Jeroen Belleman

Now that I understand better how that MPPT circuit is
supposed to work, I simulated it (in C, not in LTspice).
It works very nicely indeed, periodically shifting back
and forth a few percent over the optimum at both sides.
The averaged power drawn from the array is well over 99%
of the optimum, as you stated.

A very nice feature is that it needs to know neither the
number of cells, nor the expected current. A very nifty
circuit indeed.

Jeroen Belleman

 

But in Denmark the cost of the arrays are about
10.000 USD for 6kW.

USD 1.6/W is indeed expensive. I am getting flexible
at $0.50/W right now. Fixed panels are even cheaper,
perhaps $0.30/W.

" You were pricing adjusting auto-angle panel arrays?"

These are flexible panels with adhesive backing, just roll out and stick on the roof. Much easier to install. Got 20 pcs yesterday, getting another 30 today. I think they have around 200 left. I need to find place to store them for now.

" My roof was expensive, $4/W installed, four years ago,
should be under half that now. Bare panels $0.5/W now."

 

On Mon, 04 Nov 2019 17:24:22 -0800, John Larkin
<jlarkin@highland_atwork_technology.com> wrote:

On Mon, 4 Nov 2019 17:11:20 -0800 (PST),
bloggs.fredbloggs.fred@gmail.com wrote:

On Friday, November 1, 2019 at 6:41:03 PM UTC-4, John Larkin wrote:
On Fri, 1 Nov 2019 15:24:21 -0700 (PDT), Phil Allison
pallison49@gmail.com> wrote:

John Larkin wrote:

------------------


Solar cells are inefficient, and resistive heaters are inefficient.


** Really ?

Other than heat, what do resistive heaters convert electricity into ?

Far IR light?


..... Phil

Some people claim that resistive heating is 100% efficient. Then a
heat pump must be 400% efficient.

They don't use efficiency, they use a measure called coefficient of performance, COP, which is ratio of useful heat output to totality of input energy required to produce it. Electric resistance heating actually has higher COP than the average fossil fuel burner, but the cost factor does the electric in.
https://en.wikipedia.org/wiki/Coefficient_of_performance



If a utility burns gas to make electricity, and I use that electricity
in resistive heaters, to heat my house or to heat water, I *think* it
would be more efficient to burn the gas locally, for the heat.

Simple coal/nuclear and gas power plants have an electric efficiency
about 30-40 %, thus with resistive heating that would also be the
heating efficiency,

However, if a heat pump with COP 3 or better, about the same heat can
be recovered as burning the gas locally for heating. If the power
plant low quality heat is used for district heating to local users,
the fuel energy can be used very effectively.

 

[Winfield Hill]

edward.ming.lee@gmail.com wrote...

But in Denmark the cost of the arrays are about
10.000 USD for 6kW.

USD 1.6/W is indeed expensive. I am getting flexible
at $0.50/W right now. Fixed panels are even cheaper,
perhaps $0.30/W.

You were pricing adjusting auto-angle panel arrays?

My roof was expensive, $4/W installed, four years ago,
should be under half that now. Bare panels $0.5/W now.


--
Thanks,
- Win

 

On Tuesday, 5 November 2019 14:46:51 UTC+1, Jeroen Belleman wrote:

I (Jeroen) wrote:

klaus.kragelund@gmail.com wrote:

[Snip!]


The accuracy of 0.3% is cheap, just takes some thought. As I wrote, much lower than 1 USD

Increasing efficiency of the converter is costly, cannot be compared

Cheers

Klaus

I don't understand that circuit very well. [...]

Jeroen Belleman

Now that I understand better how that MPPT circuit is
supposed to work, I simulated it (in C, not in LTspice).
It works very nicely indeed, periodically shifting back
and forth a few percent over the optimum at both sides.
The averaged power drawn from the array is well over 99%
of the optimum, as you stated.

A very nice feature is that it needs to know neither the
number of cells, nor the expected current. A very nifty
circuit indeed.

Yeah, and it works

It is used in many different satellites in operation, been through thorough reviews by a lot of people. We never had an issue with it

I tried to do an alternative design with an ADC for sampling, so the S/H would have zero droop, but it became simply too complex.

I did add a twist that would let it operate with very high capacitance on the array, worked very good

Cheers

Klaus

 

[Rick C]

On Tuesday, November 5, 2019 at 7:41:11 AM UTC-5, Martin Brown wrote:

On 04/11/2019 15:28, Rick C wrote:
On Monday, November 4, 2019 at 8:06:24 AM UTC-5, Martin Brown wrote:
On 03/11/2019 17:15, Rick C wrote:
On Sunday, November 3, 2019 at 4:32:49 AM UTC-5, Martin Brown wrote:

Plenty of designs about usually for heating swimming pools or bulk
thermal stores.

I'm sure there are lots of ways to do this job more efficiently, but
really? You want the guy to run plumbing instead of wires for a 300
watt heater?

It is a way more appropriate solution to the problem than the DIY solar
PV approach and would be able to supply more heat than a puny 300W.

It's also a lot more work for a DIY project. A LOT more work.

It's not electronics but I'd say it is about the same amount of work and
it does involve some soldering of copper just with much bigger joints.
It will function considerably better although obviously it works best in
midsummer when you might be glad of the cool air in the basement.

I don't know what plumbing you have done, but the stuff I've done has been much harder than plugging in some connectors and maybe soldering a wire. I'm glad you find plumbing so easy.

--

Rick C.

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

 

[Rick C]

On Tuesday, November 5, 2019 at 5:01:03 AM UTC-5, Jasen Betts wrote:

On 2019-11-04, John S <Sophi.2@invalid.org> wrote:
On 11/4/2019 8:14 AM, tabbypurr@gmail.com wrote:
On Monday, 4 November 2019 05:10:32 UTC, Bill Sloman wrote:
On Monday, November 4, 2019 at 1:15:30 PM UTC+11, tabby wrote:
On Monday, 4 November 2019 01:20:14 UTC, Bill Sloman wrote:
On Monday, November 4, 2019 at 3:48:17 AM UTC+11, tabby wrote:
On Saturday, 2 November 2019 22:27:17 UTC, John S wrote:

Heating the air does not remove the moisture. The water content in the
air stays constant, just the *relative* humidity goes down. To remove
the moisture you must cool the air to below the dew point. You can then
heat the air if needed.

some half truths there

But NT doesn't know, and can't tell us, which bits are less than perfectly accurate.

Sure I can. And for once I will reply despite your childishness.


I can't find anything wrong with either statement, so this looks more like NT not understanding what is being said and.

Dehumidifiers do cool the incoming air below it's dew point. The cold, dry air is then passed over the other end of the heat-pump circuit to warm it up again (and recondense the refrigerant that little bit faster).


Heating air doesn't directly change its moisture content, though it does lower its RH.

So NT agrees that this statement was entirely correct

But heated indoor air inevitably exchanges with outdoor air in domestic properties, which is on average lower in moisture content, and which then drops RH as it warms.

This is just irrelevant carping. Out-door air was be wetter or drier than indoor air, or warmer or cooler. Swapping air with the outside world is ventilation.

Exchange between heated indoor air & unheated outdoor air is the mechanism by which the great majority of houses are dehumidified.

It's an incidental feature of the more general process of ventilation.. If you are getting worried by damp patches on the walls, dehumidifiers attack the problem directly. NT is in evasive mode here.

Dehumidifiers do cool the incoming air below it's dew point. The cold, dry

To remove
the moisture you must cool the air to below the dew point.

Not really, on both counts there are other options too. Desiccant wheel dehumidifiers don't use chilling at all. Nor do box-of-salt type ones, even though they're of minimal use.

I have seen both sorts of dehumidifier sold for domestic use. It's nuts, but some hardware stores cater for people with little money and even less sense. As NT admits, they don't work well enough to be of much use, and they certainly aren't cost effective.

Laboratory desiccators frequently used water absorbers which can be regenerated by heating, but strictly for tiny volumes of air.

I know from Bill's history here that any moment of sense from him is merely an invitation to enter into his spiral of madness. I'm not interested in doing so & don't care what he has to say.

There's no madness involved, if we exclude NT's inane enthusiasm for unhelpful pontification.


Lol. And desiccant wheel dehumidifiers work just fine.


And what do you do with the desiccant when it is saturated with water?

You blow hot air over it until it dries, and the wheel rotates the
dessicant back into the damp air flow.

What do you do with the hot, damp air? Blow it into the cool, damp air so you have warm damp air?

--

Rick C.

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

 

[Bill Sloman]

On Wednesday, November 6, 2019 at 12:30:48 AM UTC+11, tabb...@gmail.com wrote:

On Tuesday, 5 November 2019 06:07:55 UTC, Bill Sloman wrote:
On Tuesday, November 5, 2019 at 3:43:43 PM UTC+11, tabby wrote:
On Monday, 4 November 2019 14:54:48 UTC, Winfield Hill wrote:
John S wrote...
tabbypurr wrote:

And desiccant wheel dehumidifiers work just fine.

And what do you do with the desiccant when it is
saturated with water?

Do they become humidifiers, when (if) the air
otherwise becomes dry again?

The wheel slowly rotates, drying room air on one side, and drying the desiccant on the other. Pass hot air through it, which then circulates around a metal compartment. The metal is cooled by the room air, forming condensation thus removing damp from the compartment. Condensate drips into a container or down a pipe. These machines are ideal for unheated spaces, where compressor types become near useless.

I wonder why NT thinks that?

because it's correct

NT has probably run into a dehumifier that don't let its condensing coil get below the freezing point, where it'd ice up.

There are ways of dealing with this - as anybody who owns a modern freezer knows. You warm up the condensor coils from time to time to melt the ice and let it run off as water. This pretty much demands using a microcontroller and extra sensors.

NT doesn't think about stuff like that, so he probably ran into a dehumidifier that didn't work well in a cold room some time ago , and never bothered to work out why.

<snip>

--
Bill Sloman, Sydney

 

[Carl]

"Rick C" wrote in message
news:c986b730-0e40-4b7f-a1a6-4b7e0d0b6bb3@googlegroups.com...

On Tuesday, November 5, 2019 at 5:01:03 AM UTC-5, Jasen Betts wrote:
On 2019-11-04, John S <Sophi.2@invalid.org> wrote:
On 11/4/2019 8:14 AM, tabbypurr@gmail.com wrote:
On Monday, 4 November 2019 05:10:32 UTC, Bill Sloman wrote:
On Monday, November 4, 2019 at 1:15:30 PM UTC+11, tabby wrote:
On Monday, 4 November 2019 01:20:14 UTC, Bill Sloman wrote:
On Monday, November 4, 2019 at 3:48:17 AM UTC+11, tabby wrote:
On Saturday, 2 November 2019 22:27:17 UTC, John S wrote:

Heating the air does not remove the moisture. The water content
in the
air stays constant, just the *relative* humidity goes down. To
remove
the moisture you must cool the air to below the dew point. You
can then
heat the air if needed.

some half truths there

But NT doesn't know, and can't tell us, which bits are less than
perfectly accurate.

Sure I can. And for once I will reply despite your childishness.


I can't find anything wrong with either statement, so this looks
more like NT not understanding what is being said and.

Dehumidifiers do cool the incoming air below it's dew point. The
cold, dry air is then passed over the other end of the heat-pump
circuit to warm it up again (and recondense the refrigerant that
little bit faster).


Heating air doesn't directly change its moisture content, though it
does lower its RH.

So NT agrees that this statement was entirely correct

But heated indoor air inevitably exchanges with outdoor air in
domestic properties, which is on average lower in moisture content,
and which then drops RH as it warms.

This is just irrelevant carping. Out-door air was be wetter or drier
than indoor air, or warmer or cooler. Swapping air with the outside
world is ventilation.

Exchange between heated indoor air & unheated outdoor air is the
mechanism by which the great majority of houses are dehumidified.

It's an incidental feature of the more general process of
ventilation. If you are getting worried by damp patches on the walls,
dehumidifiers attack the problem directly. NT is in evasive mode
here.

Dehumidifiers do cool the incoming air below it's dew point. The
cold, dry

To remove
the moisture you must cool the air to below the dew point.

Not really, on both counts there are other options too. Desiccant
wheel dehumidifiers don't use chilling at all. Nor do box-of-salt
type ones, even though they're of minimal use.

I have seen both sorts of dehumidifier sold for domestic use. It's
nuts, but some hardware stores cater for people with little money and
even less sense. As NT admits, they don't work well enough to be of
much use, and they certainly aren't cost effective.

Laboratory desiccators frequently used water absorbers which can be
regenerated by heating, but strictly for tiny volumes of air.

I know from Bill's history here that any moment of sense from him is
merely an invitation to enter into his spiral of madness. I'm not
interested in doing so & don't care what he has to say.

There's no madness involved, if we exclude NT's inane enthusiasm for
unhelpful pontification.


Lol. And desiccant wheel dehumidifiers work just fine.


And what do you do with the desiccant when it is saturated with water?

You blow hot air over it until it dries, and the wheel rotates the
dessicant back into the damp air flow.

What do you do with the hot, damp air? Blow it into the cool, damp air so
you have warm damp air?

Picture a wall with a long narrow slot. Put a wheel in the slot with one
end of the axle on one side of the slot and the other end of the axle on the
other side of the slot so half the wheel is on each side of the wall, and
put a sliding seal on the edges of the slot so each side is sealed from the
other side. Coat the wheel with dessicant. One side of the wall is exposed
to interior air and the interior moisture is absorbed by the dessicant as
this air is blown over the wheel. Rotate the wheel so the now saturated
dessicant is on the other side of the wall, exposed to the outside air.
Blow warm outside air over the dessicant to dry it out, exhausting the moist
warm air to the outside. Now rotate the wheel so the dry half is back
inside where it cools back down and takes up more moisture. Repeat ad
nauseum. Actually, of course, the wheel always turns but you get the idea.
The problems are the sliding seals, the lifespan of the dessicant, and the
heat carried into the house by the warm wheel, assuming it is hotter
outside.

--
Regards,
Carl Ijames

 

On Mon, 4 Nov 2019 09:33:02 -0800 (PST), whit3rd <whit3rd@gmail.com>
wrote:

On Sunday, November 3, 2019 at 6:18:19 PM UTC-8, k...@notreal.com wrote:
On Sat, 2 Nov 2019 16:08:21 -0700 (PDT), Rick C
gnuarm.deletethisbit@gmail.com> wrote:

On Saturday, November 2, 2019 at 4:25:01 PM UTC-4, Whoey Louie wrote:
On Saturday, November 2, 2019 at 2:40:55 PM UTC-4, Rick C wrote:

Basements are typically not insulated because being below ground they are close to the optimum temperature. Only above ground walls are insulated.

Only if you think ~55F is the optimum temperature.

Where is this that basement walls are a magic 55F?

It's a good approximation to the situation here in Seattle. Very useful, any pipes in the basement
are not worth worrying about, they'll never freeze.

In the basement, sure. You have a lot of heat leaking from the floor
above. The pipes in our basement in Vermont didn't freeze, either.
The sill cocks had the business end on the inside of the building, in
the basement.

Basement insulation is typically a few feet down from ground level, then... stops. If the
basement is climate controlled, the floor and much of the wall is just NOT capable of
large heat/cooling leak, because the tons of subsoil and rock are not very (thermally) connected
to the local weather. High heat-flow resistance, and large heat capacity, makes
the familiar RC filter...

No, inside insulation generally goes to the floor. Foundation
insulation may not go all the way down but that's just cheaping out.

 

On Sun, 3 Nov 2019 22:33:15 -0800 (PST), Rick C
<gnuarm.deletethisbit@gmail.com> wrote:

On Sunday, November 3, 2019 at 11:02:24 PM UTC-5, Whoey Louie wrote:
On Sunday, November 3, 2019 at 9:18:19 PM UTC-5, k...@notreal.com wrote:
On Sat, 2 Nov 2019 16:08:21 -0700 (PDT), Rick C
gnuarm.deletethisbit@gmail.com> wrote:

On Saturday, November 2, 2019 at 4:25:01 PM UTC-4, Whoey Louie wrote:
On Saturday, November 2, 2019 at 2:40:55 PM UTC-4, Rick C wrote:
On Saturday, November 2, 2019 at 12:34:13 PM UTC-4, jla...@highlandsniptechnology.com wrote:

Sunlight looks bright, but it's low density intermittent energy and
hard to apply. It's even worse in winter. Better to insulate the
basement, probably.

Basements are typically not insulated because being below ground they are close to the optimum temperature. Only above ground walls are insulated.

Only if you think ~55F is the optimum temperature. Otherwise a basement
is like having an uninsulated living space when it's 55F outside.
Actually it's worse than that, because when it's 55F outside, sunlight
is a big help in warming the living space. In the basement you don't
have that. IMO, it most of the US if you're going to finish the basement
and use it as living space, you'd be nuts not to insulate it.

Where is this that basement walls are a magic 55F? I know in Vermont,
the frost line can get down to at least 7'. ...and yes, in much of
the country basement walls *are* insulated if it's finished living
space.



That's the issue. Most basements aren't insulated because they are not living spaces and they are not heated. If they are, then they are generally insulated in colder climates.

That's not what I was talking about. I guess I was generalizing too much. While I think a 7 foot deep frost in Vermont is a bit overly dramatic, the 55 degree temperature is around here. In places like Vermont the underground temp is around mid 40s, so likely the full basement wall is insulated. If the freeze line really did get to 7 foot down, there would be a lot of frozen well pipes every year. They have to come up enough to enter the house at some point.

Keep in mind that while a 55°F basement wall may be a bit cool in the winter, it feels really nice in the summer. So insulating the underground portion of the wall will give a savings while heating at the expense of requiring more cooling in the summer. I expect 55°F is a very nice compromise between the two.

Idiot. They know what the frost line is and prepare for it. And,
yes, in particularly cold winters there are water pipes frozen. Yes,
and 7' down.

I still want to know where I can buy some of this magic 55F dirt.

 

On Sun, 3 Nov 2019 20:02:19 -0800 (PST), Whoey Louie
<trader4@optonline.net> wrote:

On Sunday, November 3, 2019 at 9:18:19 PM UTC-5, k...@notreal.com wrote:
On Sat, 2 Nov 2019 16:08:21 -0700 (PDT), Rick C
gnuarm.deletethisbit@gmail.com> wrote:

On Saturday, November 2, 2019 at 4:25:01 PM UTC-4, Whoey Louie wrote:
On Saturday, November 2, 2019 at 2:40:55 PM UTC-4, Rick C wrote:
On Saturday, November 2, 2019 at 12:34:13 PM UTC-4, jla...@highlandsniptechnology.com wrote:

Sunlight looks bright, but it's low density intermittent energy and
hard to apply. It's even worse in winter. Better to insulate the
basement, probably.

Basements are typically not insulated because being below ground they are close to the optimum temperature. Only above ground walls are insulated.

Only if you think ~55F is the optimum temperature. Otherwise a basement
is like having an uninsulated living space when it's 55F outside.
Actually it's worse than that, because when it's 55F outside, sunlight
is a big help in warming the living space. In the basement you don't
have that. IMO, it most of the US if you're going to finish the basement
and use it as living space, you'd be nuts not to insulate it.

Where is this that basement walls are a magic 55F? I know in Vermont,
the frost line can get down to at least 7'. ...and yes, in much of
the country basement walls *are* insulated if it's finished living
space.



That's the issue. Most basements aren't insulated because they are not living spaces and they are not heated. If they are, then they are generally insulated in colder climates.

I think you greatly underestimate the number of homes with finished
basements.

It would appear the majority of homes built in the
US were built by nuts then. The thermal load of a concrete wall with 55°F on the other side is not so large really. In fact, most spaces need to be cooled if they don't have a path for the internally generated heat to escape. Don't try to compare an insulated wall with a huge thermal hole in it (windows) to a basement wall. Temps inside don't really need heat until the outside temps get fairly cool, below 55°F. As someone mentioned, it is the dampness of basements that gets to you more.

Where does this magic 55F dirt come from?

<crickets>

 

[Rick C]

On Tuesday, November 5, 2019 at 10:08:11 PM UTC-5, Carl wrote:

"Rick C" wrote in message
news:c986b730-0e40-4b7f-a1a6-4b7e0d0b6bb3@googlegroups.com...

On Tuesday, November 5, 2019 at 5:01:03 AM UTC-5, Jasen Betts wrote:
On 2019-11-04, John S <Sophi.2@invalid.org> wrote:
On 11/4/2019 8:14 AM, tabbypurr@gmail.com wrote:

Lol. And desiccant wheel dehumidifiers work just fine.


And what do you do with the desiccant when it is saturated with water?

You blow hot air over it until it dries, and the wheel rotates the
dessicant back into the damp air flow.

What do you do with the hot, damp air? Blow it into the cool, damp air so
you have warm damp air?

Picture a wall with a long narrow slot. Put a wheel in the slot with one
end of the axle on one side of the slot and the other end of the axle on the
other side of the slot so half the wheel is on each side of the wall, and
put a sliding seal on the edges of the slot so each side is sealed from the
other side. Coat the wheel with dessicant. One side of the wall is exposed
to interior air and the interior moisture is absorbed by the dessicant as
this air is blown over the wheel. Rotate the wheel so the now saturated
dessicant is on the other side of the wall, exposed to the outside air.
Blow warm outside air over the dessicant to dry it out, exhausting the moist
warm air to the outside. Now rotate the wheel so the dry half is back
inside where it cools back down and takes up more moisture. Repeat ad
nauseum. Actually, of course, the wheel always turns but you get the idea.
The problems are the sliding seals, the lifespan of the dessicant, and the
heat carried into the house by the warm wheel, assuming it is hotter
outside.

Trouble is that here, in the summer, the wheel would pick up moisture from the warm, wet air outside and bring that into the house where the cool, dry air (because of the air conditioning) would pick up the moisture. So both heat and moisture would be transferred from the outside to the inside. I guess that's better than opening a window since it keeps the dirt out.

I guess this works well in the same regions where swamp coolers are functional. In fact, they can be used together. Use a swamp cooler to cool the inside air but making it damp, then use the desiccant wheel to move the moisture back outside while letting some heat back in.

--

Rick C.

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

 

[Carl]

"Rick C" wrote in message
news:8956e476-cbe6-4ce9-b08e-108316baecec@googlegroups.com...

On Tuesday, November 5, 2019 at 10:08:11 PM UTC-5, Carl wrote:
"Rick C" wrote in message
news:c986b730-0e40-4b7f-a1a6-4b7e0d0b6bb3@googlegroups.com...

On Tuesday, November 5, 2019 at 5:01:03 AM UTC-5, Jasen Betts wrote:
On 2019-11-04, John S <Sophi.2@invalid.org> wrote:
On 11/4/2019 8:14 AM, tabbypurr@gmail.com wrote:

Lol. And desiccant wheel dehumidifiers work just fine.


And what do you do with the desiccant when it is saturated with
water?

You blow hot air over it until it dries, and the wheel rotates the
dessicant back into the damp air flow.

What do you do with the hot, damp air? Blow it into the cool, damp air
so
you have warm damp air?

Picture a wall with a long narrow slot. Put a wheel in the slot with one
end of the axle on one side of the slot and the other end of the axle on
the
other side of the slot so half the wheel is on each side of the wall, and
put a sliding seal on the edges of the slot so each side is sealed from
the
other side. Coat the wheel with dessicant. One side of the wall is
exposed
to interior air and the interior moisture is absorbed by the dessicant as
this air is blown over the wheel. Rotate the wheel so the now saturated
dessicant is on the other side of the wall, exposed to the outside air.
Blow warm outside air over the dessicant to dry it out, exhausting the
moist
warm air to the outside. Now rotate the wheel so the dry half is back
inside where it cools back down and takes up more moisture. Repeat ad
nauseum. Actually, of course, the wheel always turns but you get the
idea.
The problems are the sliding seals, the lifespan of the dessicant, and
the
heat carried into the house by the warm wheel, assuming it is hotter
outside.

Trouble is that here, in the summer, the wheel would pick up moisture from
the warm, wet air outside and bring that into the house where the cool, dry
air (because of the air conditioning) would pick up the moisture. So both
heat and moisture would be transferred from the outside to the inside. I
guess that's better than opening a window since it keeps the dirt out.

I guess this works well in the same regions where swamp coolers are
functional. In fact, they can be used together. Use a swamp cooler to
cool the inside air but making it damp, then use the desiccant wheel to
move the moisture back outside while letting some heat back in.

That's what I get for posting while watching TV, I left out the part where
you heat the wheel while it is outside. That's what drives the water out of
the dessicant, and you blow outside air over it just to carry the water
vapor away. Some of that water will condense so you need to provide a
liquid water drain, too, along with the air exhaust flow. That means the
wheel is a good bit hotter than the outside temperature when it cycles back
inside, which makes the added heat load that much worse.

--
Regards,
Carl Ijames

 

[Rick C]

On Wednesday, November 6, 2019 at 9:28:14 AM UTC-5, Carl wrote:

"Rick C" wrote in message
news:8956e476-cbe6-4ce9-b08e-108316baecec@googlegroups.com...

On Tuesday, November 5, 2019 at 10:08:11 PM UTC-5, Carl wrote:
"Rick C" wrote in message
news:c986b730-0e40-4b7f-a1a6-4b7e0d0b6bb3@googlegroups.com...

On Tuesday, November 5, 2019 at 5:01:03 AM UTC-5, Jasen Betts wrote:
On 2019-11-04, John S <Sophi.2@invalid.org> wrote:
On 11/4/2019 8:14 AM, tabbypurr@gmail.com wrote:

Lol. And desiccant wheel dehumidifiers work just fine.


And what do you do with the desiccant when it is saturated with
water?

You blow hot air over it until it dries, and the wheel rotates the
dessicant back into the damp air flow.

What do you do with the hot, damp air? Blow it into the cool, damp air
so
you have warm damp air?

Picture a wall with a long narrow slot. Put a wheel in the slot with one
end of the axle on one side of the slot and the other end of the axle on
the
other side of the slot so half the wheel is on each side of the wall, and
put a sliding seal on the edges of the slot so each side is sealed from
the
other side. Coat the wheel with dessicant. One side of the wall is
exposed
to interior air and the interior moisture is absorbed by the dessicant as
this air is blown over the wheel. Rotate the wheel so the now saturated
dessicant is on the other side of the wall, exposed to the outside air..
Blow warm outside air over the dessicant to dry it out, exhausting the
moist
warm air to the outside. Now rotate the wheel so the dry half is back
inside where it cools back down and takes up more moisture. Repeat ad
nauseum. Actually, of course, the wheel always turns but you get the
idea.
The problems are the sliding seals, the lifespan of the dessicant, and
the
heat carried into the house by the warm wheel, assuming it is hotter
outside.

Trouble is that here, in the summer, the wheel would pick up moisture from
the warm, wet air outside and bring that into the house where the cool, dry
air (because of the air conditioning) would pick up the moisture. So both
heat and moisture would be transferred from the outside to the inside. I
guess that's better than opening a window since it keeps the dirt out.

I guess this works well in the same regions where swamp coolers are
functional. In fact, they can be used together. Use a swamp cooler to
cool the inside air but making it damp, then use the desiccant wheel to
move the moisture back outside while letting some heat back in.

That's what I get for posting while watching TV, I left out the part where
you heat the wheel while it is outside. That's what drives the water out of
the dessicant, and you blow outside air over it just to carry the water
vapor away. Some of that water will condense so you need to provide a
liquid water drain, too, along with the air exhaust flow. That means the
wheel is a good bit hotter than the outside temperature when it cycles back
inside, which makes the added heat load that much worse.

Ok, I see where you are going with this. You want to cool the desiccant with water before it rotates back into the home? LOL

So a double energy whammy! Pay to generate the extra heat to be added to the heat already being picked up by the wheel and brought inside. Then pay for additional A/C to cool the place... but doesn't the A/C remove moisture from the air? Why would you need both?

Ah, the desiccant is used with the swamp coolers which DON'T reduce the inside humidity! Got it!

--

Rick C.

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

 

On Wednesday, 6 November 2019 15:56:24 UTC, Rick C wrote:

On Wednesday, November 6, 2019 at 9:28:14 AM UTC-5, Carl wrote:
"Rick C" wrote in message
news:8956e476-cbe6-4ce9-b08e-108316baecec@googlegroups.com...

On Tuesday, November 5, 2019 at 10:08:11 PM UTC-5, Carl wrote:
"Rick C" wrote in message
news:c986b730-0e40-4b7f-a1a6-4b7e0d0b6bb3@googlegroups.com...

On Tuesday, November 5, 2019 at 5:01:03 AM UTC-5, Jasen Betts wrote:
On 2019-11-04, John S <Sophi.2@invalid.org> wrote:
On 11/4/2019 8:14 AM, tabbypurr wrote:

Lol. And desiccant wheel dehumidifiers work just fine.


And what do you do with the desiccant when it is saturated with
water?

You blow hot air over it until it dries, and the wheel rotates the
dessicant back into the damp air flow.

What do you do with the hot, damp air? Blow it into the cool, damp air
so
you have warm damp air?

Picture a wall with a long narrow slot. Put a wheel in the slot with one
end of the axle on one side of the slot and the other end of the axle on
the
other side of the slot so half the wheel is on each side of the wall, and
put a sliding seal on the edges of the slot so each side is sealed from
the
other side. Coat the wheel with dessicant. One side of the wall is
exposed
to interior air and the interior moisture is absorbed by the dessicant as
this air is blown over the wheel. Rotate the wheel so the now saturated
dessicant is on the other side of the wall, exposed to the outside air.
Blow warm outside air over the dessicant to dry it out, exhausting the
moist
warm air to the outside. Now rotate the wheel so the dry half is back
inside where it cools back down and takes up more moisture. Repeat ad
nauseum. Actually, of course, the wheel always turns but you get the
idea.
The problems are the sliding seals, the lifespan of the dessicant, and
the
heat carried into the house by the warm wheel, assuming it is hotter
outside.

Trouble is that here, in the summer, the wheel would pick up moisture from
the warm, wet air outside and bring that into the house where the cool, dry
air (because of the air conditioning) would pick up the moisture. So both
heat and moisture would be transferred from the outside to the inside. I
guess that's better than opening a window since it keeps the dirt out.

I guess this works well in the same regions where swamp coolers are
functional. In fact, they can be used together. Use a swamp cooler to
cool the inside air but making it damp, then use the desiccant wheel to
move the moisture back outside while letting some heat back in.

That's what I get for posting while watching TV, I left out the part where
you heat the wheel while it is outside. That's what drives the water out of
the dessicant, and you blow outside air over it just to carry the water
vapor away. Some of that water will condense so you need to provide a
liquid water drain, too, along with the air exhaust flow. That means the
wheel is a good bit hotter than the outside temperature when it cycles back
inside, which makes the added heat load that much worse.

Ok, I see where you are going with this. You want to cool the desiccant with water before it rotates back into the home? LOL

So a double energy whammy! Pay to generate the extra heat to be added to the heat already being picked up by the wheel and brought inside. Then pay for additional A/C to cool the place... but doesn't the A/C remove moisture from the air? Why would you need both?

Ah, the desiccant is used with the swamp coolers which DON'T reduce the inside humidity! Got it!

Whatever you've got I hope you get it treated.


NT

 

On Wednesday, 6 November 2019 01:33:11 UTC, Rick C wrote:

On Tuesday, November 5, 2019 at 5:01:03 AM UTC-5, Jasen Betts wrote:
On 2019-11-04, John S <Sophi.2@invalid.org> wrote:
On 11/4/2019 8:14 AM, tabbypurr wrote:
On Monday, 4 November 2019 05:10:32 UTC, Bill Sloman wrote:
On Monday, November 4, 2019 at 1:15:30 PM UTC+11, tabby wrote:
On Monday, 4 November 2019 01:20:14 UTC, Bill Sloman wrote:
On Monday, November 4, 2019 at 3:48:17 AM UTC+11, tabby wrote:
On Saturday, 2 November 2019 22:27:17 UTC, John S wrote:

Heating the air does not remove the moisture. The water content in the
air stays constant, just the *relative* humidity goes down. To remove
the moisture you must cool the air to below the dew point. You can then
heat the air if needed.

some half truths there

But NT doesn't know, and can't tell us, which bits are less than perfectly accurate.

Sure I can. And for once I will reply despite your childishness.


I can't find anything wrong with either statement, so this looks more like NT not understanding what is being said and.

Dehumidifiers do cool the incoming air below it's dew point. The cold, dry air is then passed over the other end of the heat-pump circuit to warm it up again (and recondense the refrigerant that little bit faster).


Heating air doesn't directly change its moisture content, though it does lower its RH.

So NT agrees that this statement was entirely correct

But heated indoor air inevitably exchanges with outdoor air in domestic properties, which is on average lower in moisture content, and which then drops RH as it warms.

This is just irrelevant carping. Out-door air was be wetter or drier than indoor air, or warmer or cooler. Swapping air with the outside world is ventilation.

Exchange between heated indoor air & unheated outdoor air is the mechanism by which the great majority of houses are dehumidified.

It's an incidental feature of the more general process of ventilation. If you are getting worried by damp patches on the walls, dehumidifiers attack the problem directly. NT is in evasive mode here.

Dehumidifiers do cool the incoming air below it's dew point. The cold, dry

To remove
the moisture you must cool the air to below the dew point.

Not really, on both counts there are other options too. Desiccant wheel dehumidifiers don't use chilling at all. Nor do box-of-salt type ones, even though they're of minimal use.

I have seen both sorts of dehumidifier sold for domestic use. It's nuts, but some hardware stores cater for people with little money and even less sense. As NT admits, they don't work well enough to be of much use, and they certainly aren't cost effective.

Laboratory desiccators frequently used water absorbers which can be regenerated by heating, but strictly for tiny volumes of air.

I know from Bill's history here that any moment of sense from him is merely an invitation to enter into his spiral of madness. I'm not interested in doing so & don't care what he has to say.

There's no madness involved, if we exclude NT's inane enthusiasm for unhelpful pontification.


Lol. And desiccant wheel dehumidifiers work just fine.


And what do you do with the desiccant when it is saturated with water?

You blow hot air over it until it dries, and the wheel rotates the
dessicant back into the damp air flow.

What do you do with the hot, damp air? Blow it into the cool, damp air so you have warm damp air?

That was already explained. Circulate it through a metal container whereupon condensation occurs on the metal, which is collected for disposal.


NT

 

On Wednesday, 6 November 2019 14:28:14 UTC, Carl wrote:

"Rick C" wrote in message
news:8956e476-cbe6-4ce9-b08e-108316baecec@googlegroups.com...

On Tuesday, November 5, 2019 at 10:08:11 PM UTC-5, Carl wrote:
"Rick C" wrote in message
news:c986b730-0e40-4b7f-a1a6-4b7e0d0b6bb3@googlegroups.com...

On Tuesday, November 5, 2019 at 5:01:03 AM UTC-5, Jasen Betts wrote:
On 2019-11-04, John S <Sophi.2@invalid.org> wrote:
On 11/4/2019 8:14 AM, tabbypurr wrote:

Lol. And desiccant wheel dehumidifiers work just fine.


And what do you do with the desiccant when it is saturated with
water?

You blow hot air over it until it dries, and the wheel rotates the
dessicant back into the damp air flow.

What do you do with the hot, damp air? Blow it into the cool, damp air
so
you have warm damp air?

Picture a wall with a long narrow slot. Put a wheel in the slot with one
end of the axle on one side of the slot and the other end of the axle on
the
other side of the slot so half the wheel is on each side of the wall, and
put a sliding seal on the edges of the slot so each side is sealed from
the
other side. Coat the wheel with dessicant. One side of the wall is
exposed
to interior air and the interior moisture is absorbed by the dessicant as
this air is blown over the wheel. Rotate the wheel so the now saturated
dessicant is on the other side of the wall, exposed to the outside air.
Blow warm outside air over the dessicant to dry it out, exhausting the
moist
warm air to the outside. Now rotate the wheel so the dry half is back
inside where it cools back down and takes up more moisture. Repeat ad
nauseum. Actually, of course, the wheel always turns but you get the
idea.
The problems are the sliding seals, the lifespan of the dessicant, and
the
heat carried into the house by the warm wheel, assuming it is hotter
outside.

Trouble is that here, in the summer, the wheel would pick up moisture from
the warm, wet air outside and bring that into the house where the cool, dry
air (because of the air conditioning) would pick up the moisture. So both
heat and moisture would be transferred from the outside to the inside. I
guess that's better than opening a window since it keeps the dirt out.

I guess this works well in the same regions where swamp coolers are
functional. In fact, they can be used together. Use a swamp cooler to
cool the inside air but making it damp, then use the desiccant wheel to
move the moisture back outside while letting some heat back in.

That's what I get for posting while watching TV, I left out the part where
you heat the wheel while it is outside. That's what drives the water out of
the dessicant, and you blow outside air over it just to carry the water
vapor away. Some of that water will condense so you need to provide a
liquid water drain, too, along with the air exhaust flow. That means the
wheel is a good bit hotter than the outside temperature when it cycles back
inside, which makes the added heat load that much worse.

The added heat load is trivial via that route as the wheel is very slow moving & has trivial mass. 99% of the heat load (or somewhere in that region) comes from the condensing box.


NT