Super Simple Solar Energy

On Friday, 8 November 2019 03:45:49 UTC, Bill Sloman wrote:

On Friday, November 8, 2019 at 2:14:10 AM UTC+11, tabby wrote:
On Thursday, 7 November 2019 11:02:21 UTC, Bill Sloman wrote:
On Thursday, November 7, 2019 at 5:10:04 PM UTC+11, tabby wrote:
On Thursday, 7 November 2019 01:42:09 UTC, Bill Sloman wrote:
On Thursday, November 7, 2019 at 11:06:31 AM UTC+11, tabby wrote:

Domestic & industrial dehumidifiers normally switch off the compressor when they get to freezing point. (They continue to dehumidify until it warms up.) I say normally as I did encounter one that boosted fan speed instead.

The problem with an iced-up condensor coil is that the frost layer eventually gets thick enough to dramatically reduce the condensing area.

that would be a problem if it ever got that far. I've never known one do so.

One of the many things that NT doesn't know.

I know I've not encountered a dehumdifier that incompetently designed. No sensible engineer would let it run that way. Maybe yours do that.

You've never run into a dehumidifier used in a situation where it's condensor coils iced up.

not to the extent you describe, no, because no competent design engineer would let it run that way. Your proposal that they do is daft. (The only machines that can are historic machines with more or less zero control system.)

> As I originally pointed out, there's not a lot of water in the air when the air is cold enough that you have to run the condensing coils below freezing to get them below the dew/frost point,

no they don't need to be /below/ freezing.

> and if you've got a damp problem in that kind of place, stopping the water getting in is usually a much more cost-effective solution.

obviously dehumidifiers are normally used when that is not the case

Desiccant wheel dehumidifiers aren't designed. They are slapped together by people who haven't thought about what they are doing.

lol. Are you really that clueless?

The cluelessness is all yours. UK industry is full of half-witted executive who know exactly what they want their subordinates to build, and don't take kindly to any suggestion that what they want done could be done a different way.

so yes, you are that clueless


> Clive Sinclair isn't a typical example, but several people who had worked with him have commented on his compulsion to use the cheapest possible components, even when they were crummy enough to drive the production yield of working products below one in ten.

Sinclair's pound pinching has nothing to do with desiccant wheel dehumidifier design

You don't have more than a vague clue about this topic. What a prat.

In reality, the clueless prat here is you. You do make it very obvious.

You're wasting everyone's time here with your stupid bs.


NT

 

On Thu, 7 Nov 2019 13:42:34 -0800 (PST), Rick C
<gnuarm.deletethisbit@gmail.com> wrote:

On Thursday, November 7, 2019 at 4:10:32 PM UTC-5, dca...@krl.org wrote:
On Thursday, November 7, 2019 at 4:03:03 PM UTC-5, Rick C wrote:
On Thursday, November 7, 2019 at 2:46:01 PM UTC-5, dca...@krl.org wrote:
On Wednesday, November 6, 2019 at 11:24:20 PM UTC-5, Bill Sloman wrote:
On Thursday, November 7, 2019 at 1:37:11 PM UTC+11, dca...@krl.org wrote:
On Wednesday, November 6, 2019 at 8:42:09 PM UTC-5, Bill Sloman wrote:
On Thursday, November 7, 2019 at 11:06:31 AM UTC+11, tabb...@gmail.com wrote:
On Wednesday, 6 November 2019 03:29:58 UTC, Bill Sloman wrote:
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.

Domestic & industrial dehumidifiers normally switch off the compressor when they get to freezing point. (They continue to dehumidify until it warms up.) I say normally as I did encounter one that boosted fan speed instead.

The problem with an iced-up condensor coil is that the frost layer eventually gets thick enough to dramatically reduce the condensing area.

Increasing fan speed is unlikely to help there, unless you make it fast enough to blast off the frost crystals

Dehumidifiers are not usually designed to dehumidify very cold areas, where the condensor coil would have to held below freezing to keep it below the dew (frost) point.

Desicant wheel dehumidifiers do not have a condensor coil and work well at low temperatures..

They obviously don't have a condensor coil, and they'd work just as well at low temperature as high - which isn't very well.

Part of the job of a dehumidifier is to run a lot of air through the bit that takes out the water, and solid desiccants don't react well to having a lot of air blasted through them.

They could be. It's not an intrinsic fault of the heat-pump dehumidifier (as you originally claimed) but merely a feature of the normal implementation of the concept for the usual market.

Dan hasn't learned to snip yet - or to think all that well. Going to Princeton (or whatever ever it was) doesn't do anything much for a Tulane-level brain.

--
Bill Sloman, Sydney

Higher IQ , better univesity, more money

Dan

What is required to be able to form compete sentences?

--

Rick C.

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

What is required to communicate with the least amount of typing?

Many times it is better to not say anything at all.

Having said that, why do you ever say anything at all?

 

easiest solar heat

paint some gallon water jugs black
fill them with water
put them out in the sun during the day
move them into the freezer at night
freezer will extract the heat and deliver it to your kitchen
step and repeat


for extra credit, instead of water, use those gel thermal cubes used to keep
picnic bags cool


unfortunately it takers many gallons to move a significant amount of heat

Mark

 

[Bill Sloman]

On Saturday, November 9, 2019 at 12:34:54 AM UTC+11, tabb...@gmail.com wrote:

On Friday, 8 November 2019 03:45:49 UTC, Bill Sloman wrote:
On Friday, November 8, 2019 at 2:14:10 AM UTC+11, tabby wrote:
On Thursday, 7 November 2019 11:02:21 UTC, Bill Sloman wrote:
On Thursday, November 7, 2019 at 5:10:04 PM UTC+11, tabby wrote:
On Thursday, 7 November 2019 01:42:09 UTC, Bill Sloman wrote:
On Thursday, November 7, 2019 at 11:06:31 AM UTC+11, tabby wrote:

Domestic & industrial dehumidifiers normally switch off the compressor when they get to freezing point. (They continue to dehumidify until it warms up.) I say normally as I did encounter one that boosted fan speed instead.

The problem with an iced-up condensor coil is that the frost layer eventually gets thick enough to dramatically reduce the condensing area..

that would be a problem if it ever got that far. I've never known one do so.

One of the many things that NT doesn't know.

I know I've not encountered a dehumdifier that incompetently designed.. No sensible engineer would let it run that way. Maybe yours do that.

You've never run into a dehumidifier used in a situation where it's condensor coils iced up.

not to the extent you describe, no, because no competent design engineer would let it run that way. Your proposal that they do is daft. (The only machines that can are historic machines with more or less zero control system..)

Dehumidifiers aren't used by their design engineers, but by the customers who have bought them. The customers are generally less well-informed than design engineers and can show up complaining about the perfectly obvious consequences of using your gear in situations with which they weren't designed to cope.

The fact that you seem to be unaware of this is telling - and fits your pretentious clown profile to perfection.

As I originally pointed out, there's not a lot of water in the air when the air is cold enough that you have to run the condensing coils below freezing to get them below the dew/frost point,

no they don't need to be /below/ freezing.

That depends on the relative humidity of the air that needs to be dehumdified, as you be aware if you had any clue about what you were talking about.

and if you've got a damp problem in that kind of place, stopping the water getting in is usually a much more cost-effective solution.

obviously dehumidifiers are normally used when that is not the case

Desiccant wheel dehumidifiers aren't designed. They are slapped together by people who haven't thought about what they are doing.

lol. Are you really that clueless?

The cluelessness is all yours. UK industry is full of half-witted executive who know exactly what they want their subordinates to build, and don't take kindly to any suggestion that what they want done could be done a different way.

so yes, you are that clueless

UK industry might have reformed since I last worked there (in 1993) but I somehow doubt it.

Clive Sinclair isn't a typical example, but several people who had worked with him have commented on his compulsion to use the cheapest possible components, even when they were crummy enough to drive the production yield of working products below one in ten.

Sinclair's pound pinching has nothing to do with desiccant wheel dehumidifier design.

He was a UK executive with a silly idea who could get away with insisting that his subordinates did something really stupid.

You don't have more than a vague clue about this topic. What a prat.

In reality, the clueless prat here is you. You do make it very obvious.

You're wasting everyone's time here with your stupid bs.

You do like to think that. The reality is that I've got heartily sick of you doing exactly that, and I'm giving you a hard time about it.

It's open season on pretentious clowns, and you are a very obvious target.

--
Bill Sloman, Sydney

 

On Saturday, 9 November 2019 03:32:17 UTC, Bill Sloman wrote:

On Saturday, November 9, 2019 at 12:34:54 AM UTC+11, tabby wrote:
On Friday, 8 November 2019 03:45:49 UTC, Bill Sloman wrote:
On Friday, November 8, 2019 at 2:14:10 AM UTC+11, tabby wrote:
On Thursday, 7 November 2019 11:02:21 UTC, Bill Sloman wrote:
On Thursday, November 7, 2019 at 5:10:04 PM UTC+11, tabby wrote:
On Thursday, 7 November 2019 01:42:09 UTC, Bill Sloman wrote:
On Thursday, November 7, 2019 at 11:06:31 AM UTC+11, tabby wrote:

Domestic & industrial dehumidifiers normally switch off the compressor when they get to freezing point. (They continue to dehumidify until it warms up.) I say normally as I did encounter one that boosted fan speed instead.

The problem with an iced-up condensor coil is that the frost layer eventually gets thick enough to dramatically reduce the condensing area.

that would be a problem if it ever got that far. I've never known one do so.

One of the many things that NT doesn't know.

I know I've not encountered a dehumdifier that incompetently designed. No sensible engineer would let it run that way. Maybe yours do that.

You've never run into a dehumidifier used in a situation where it's condensor coils iced up.

not to the extent you describe, no, because no competent design engineer would let it run that way. Your proposal that they do is daft. (The only machines that can are historic machines with more or less zero control system.)

Dehumidifiers aren't used by their design engineers, but by the customers who have bought them. The customers are generally less well-informed than design engineers and can show up complaining about the perfectly obvious consequences of using your gear in situations with which they weren't designed to cope.

The fact that you seem to be unaware of this is telling - and fits your pretentious clown profile to perfection.

As I originally pointed out, there's not a lot of water in the air when the air is cold enough that you have to run the condensing coils below freezing to get them below the dew/frost point,

no they don't need to be /below/ freezing.

That depends on the relative humidity of the air that needs to be dehumdified, as you be aware if you had any clue about what you were talking about..

and if you've got a damp problem in that kind of place, stopping the water getting in is usually a much more cost-effective solution.

obviously dehumidifiers are normally used when that is not the case

Desiccant wheel dehumidifiers aren't designed. They are slapped together by people who haven't thought about what they are doing.

lol. Are you really that clueless?

The cluelessness is all yours. UK industry is full of half-witted executive who know exactly what they want their subordinates to build, and don't take kindly to any suggestion that what they want done could be done a different way.

so yes, you are that clueless

UK industry might have reformed since I last worked there (in 1993) but I somehow doubt it.

Clive Sinclair isn't a typical example, but several people who had worked with him have commented on his compulsion to use the cheapest possible components, even when they were crummy enough to drive the production yield of working products below one in ten.

Sinclair's pound pinching has nothing to do with desiccant wheel dehumidifier design.

He was a UK executive with a silly idea who could get away with insisting that his subordinates did something really stupid.

You don't have more than a vague clue about this topic. What a prat..

In reality, the clueless prat here is you. You do make it very obvious.

You're wasting everyone's time here with your stupid bs.

You do like to think that. The reality is that I've got heartily sick of you doing exactly that, and I'm giving you a hard time about it.

It's open season on pretentious clowns, and you are a very obvious target..

It's as pointless replying to your bs as usual. Get a life. Get a sensible mental state too, it would really help. And a clue.

 

[Bill Sloman]

On Sunday, November 10, 2019 at 12:12:58 AM UTC+11, tabb...@gmail.com wrote:

On Saturday, 9 November 2019 03:32:17 UTC, Bill Sloman wrote:
On Saturday, November 9, 2019 at 12:34:54 AM UTC+11, tabby wrote:
On Friday, 8 November 2019 03:45:49 UTC, Bill Sloman wrote:
On Friday, November 8, 2019 at 2:14:10 AM UTC+11, tabby wrote:
On Thursday, 7 November 2019 11:02:21 UTC, Bill Sloman wrote:
On Thursday, November 7, 2019 at 5:10:04 PM UTC+11, tabby wrote:
On Thursday, 7 November 2019 01:42:09 UTC, Bill Sloman wrote:
On Thursday, November 7, 2019 at 11:06:31 AM UTC+11, tabby wrote:

Domestic & industrial dehumidifiers normally switch off the compressor when they get to freezing point. (They continue to dehumidify until it warms up.) I say normally as I did encounter one that boosted fan speed instead.

The problem with an iced-up condensor coil is that the frost layer eventually gets thick enough to dramatically reduce the condensing area.

that would be a problem if it ever got that far. I've never known one do so.

One of the many things that NT doesn't know.

I know I've not encountered a dehumdifier that incompetently designed. No sensible engineer would let it run that way. Maybe yours do that.

You've never run into a dehumidifier used in a situation where it's condensor coils iced up.

not to the extent you describe, no, because no competent design engineer would let it run that way. Your proposal that they do is daft. (The only machines that can are historic machines with more or less zero control system.)

Dehumidifiers aren't used by their design engineers, but by the customers who have bought them. The customers are generally less well-informed than design engineers and can show up complaining about the perfectly obvious consequences of using your gear in situations with which they weren't designed to cope.

The fact that you seem to be unaware of this is telling - and fits your pretentious clown profile to perfection.

As I originally pointed out, there's not a lot of water in the air when the air is cold enough that you have to run the condensing coils below freezing to get them below the dew/frost point,

no they don't need to be /below/ freezing.

That depends on the relative humidity of the air that needs to be dehumdified, as you be aware if you had any clue about what you were talking about.

and if you've got a damp problem in that kind of place, stopping the water getting in is usually a much more cost-effective solution.

obviously dehumidifiers are normally used when that is not the case

Desiccant wheel dehumidifiers aren't designed. They are slapped together by people who haven't thought about what they are doing.

lol. Are you really that clueless?

The cluelessness is all yours. UK industry is full of half-witted executive who know exactly what they want their subordinates to build, and don't take kindly to any suggestion that what they want done could be done a different way.

so yes, you are that clueless

UK industry might have reformed since I last worked there (in 1993) but I somehow doubt it.

Clive Sinclair isn't a typical example, but several people who had worked with him have commented on his compulsion to use the cheapest possible components, even when they were crummy enough to drive the production yield of working products below one in ten.

Sinclair's pound pinching has nothing to do with desiccant wheel dehumidifier design.

He was a UK executive with a silly idea who could get away with insisting that his subordinates did something really stupid.

You don't have more than a vague clue about this topic. What a prat.

In reality, the clueless prat here is you. You do make it very obvious.

You're wasting everyone's time here with your stupid bs.

You do like to think that. The reality is that I've got heartily sick of you doing exactly that, and I'm giving you a hard time about it.

It's open season on pretentious clowns, and you are a very obvious target.

It's as pointless replying to your bs as usual. Get a life. Get a sensible mental state too, it would really help. And a clue.

Now NT thinks that he's some kind of life coach. Any time now he's going get even more outrageous delusions of competence and decide to run for pope.

--
Bill Sloman, Sydney

 

On Saturday, 9 November 2019 14:46:05 UTC, Bill Sloman wrote:

On Sunday, November 10, 2019 at 12:12:58 AM UTC+11, tabby wrote:

It's as pointless replying to your bs as usual. Get a life. Get a sensible mental state too, it would really help. And a clue.

Now NT thinks that he's some kind of life coach. Any time now he's going get even more outrageous delusions of competence and decide to run for pope.

I see you're both ignorant of the facts AND making stuff up again. Your usual BSSBS mode.

 

[Bill Sloman]

On Sunday, November 10, 2019 at 6:41:06 AM UTC+11, tabb...@gmail.com wrote:

On Saturday, 9 November 2019 14:46:05 UTC, Bill Sloman wrote:
On Sunday, November 10, 2019 at 12:12:58 AM UTC+11, tabby wrote:

It's as pointless replying to your bs as usual. Get a life. Get a sensible mental state too, it would really help. And a clue.

Now NT thinks that he's some kind of life coach. Any time now he's going get even more outrageous delusions of competence and decide to run for pope.

I see you're both ignorant of the facts AND making stuff up again. Your usual BSSBS mode.

NT hasn't bothered to tell us which particular facts he imagines me to be ignorant of or inventing. This is standard operating procedure for pretentious clowns.

--
Bill Sloman, Sydney

 

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.

--
Regards,
Martin Brown

A solar-thermal collector with air as the working fluid is awfully
simple and rugged. YouTube abounds with examples made from aluminum
cans.
https://www.builditsolar.com/Projects/SpaceHeating/GregCanCol/GregCanCo.htm

I think aluminum foil or dryer vent-duct collectors would make more
sense given the construction labor savings.

The thermal collector is a far more efficient converter of solar
energy than a PV panel, too. Such collectors can be passive (thermosyphon)
or fan-driven from a PV panel.

I worked keenly on a whiz-bang solar thermal collector some seasons
ago, hoping for some winter heat. I came up with a decent, simple,
more-efficient-than-usual design.

Then I looked up and happened to notice it had been cloudy 9 days
out of 10 that winter, which continued the whole season -- never
mind! But if you've got some sun, it's pretty easy to make a nice
collector without too much hassle.

Cheers,
James Arthur

 

On Monday, 11 November 2019 02:30:28 UTC, dagmarg...@yahoo.com wrote:

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.

--
Regards,
Martin Brown

A solar-thermal collector with air as the working fluid is awfully
simple and rugged. YouTube abounds with examples made from aluminum
cans.
https://www.builditsolar.com/Projects/SpaceHeating/GregCanCol/GregCanCo.htm

I think aluminum foil or dryer vent-duct collectors would make more
sense given the construction labor savings.

The thermal collector is a far more efficient converter of solar
energy than a PV panel, too. Such collectors can be passive (thermosyphon)
or fan-driven from a PV panel.

I worked keenly on a whiz-bang solar thermal collector some seasons
ago, hoping for some winter heat. I came up with a decent, simple,
more-efficient-than-usual design.

Then I looked up and happened to notice it had been cloudy 9 days
out of 10 that winter, which continued the whole season -- never
mind! But if you've got some sun, it's pretty easy to make a nice
collector without too much hassle.

Cheers,
James Arthur

Black cloth collectors offer some improvement in efficiency.


NT

 

On Monday, November 11, 2019 at 5:04:08 PM UTC-5, tabb...@gmail.com wrote:

On Monday, 11 November 2019 02:30:28 UTC, dagmarg...@yahoo.com wrote:
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.

--
Regards,
Martin Brown

A solar-thermal collector with air as the working fluid is awfully
simple and rugged. YouTube abounds with examples made from aluminum
cans.
https://www.builditsolar.com/Projects/SpaceHeating/GregCanCol/GregCanCo.htm

I think aluminum foil or dryer vent-duct collectors would make more
sense given the construction labor savings.

The thermal collector is a far more efficient converter of solar
energy than a PV panel, too. Such collectors can be passive (thermosyphon)
or fan-driven from a PV panel.

I worked keenly on a whiz-bang solar thermal collector some seasons
ago, hoping for some winter heat. I came up with a decent, simple,
more-efficient-than-usual design.

Then I looked up and happened to notice it had been cloudy 9 days
out of 10 that winter, which continued the whole season -- never
mind! But if you've got some sun, it's pretty easy to make a nice
collector without too much hassle.

Cheers,
James Arthur

Black cloth collectors offer some improvement in efficiency.


NT

I was going to spray paint some aluminum foil black, IIRC. Solar
geeks have found the best-absorbing flat black paints. Aluminum
foil, appropriately supported, is simple to build, and cheap, too.

I was going to flow air on the non-painted side, to eliminate the
any possibility of vapors or smell.

I don't understand the window-screen absorbers -- ISTM they'd let
too much light pass through, wasted. Poor cross-sectional area.

Cheers,
James Arthur

 

On Tuesday, 12 November 2019 03:42:23 UTC, dagmarg...@yahoo.com wrote:

On Monday, November 11, 2019 at 5:04:08 PM UTC-5, tabby wrote:

Black cloth collectors offer some improvement in efficiency.


NT

I was going to spray paint some aluminum foil black, IIRC. Solar
geeks have found the best-absorbing flat black paints. Aluminum
foil, appropriately supported, is simple to build, and cheap, too.

I was going to flow air on the non-painted side, to eliminate the
any possibility of vapors or smell.

I don't understand the window-screen absorbers -- ISTM they'd let
too much light pass through, wasted. Poor cross-sectional area.

Cheers,
James Arthur

the fact that the air travels thru the cloth means the hot air is kept away from the front glass side, reducing heat loss. 3+ layers of cloth are used to get a dense black overall. This also reduces heat radiation outward as a lot of heat from the cloth layers just hits a neighbouring layer. Plenty of other designs work too.


NT

 

On Tuesday, November 12, 2019 at 6:59:46 PM UTC-5, tabb...@gmail.com wrote:

On Tuesday, 12 November 2019 03:42:23 UTC, dagmarg...@yahoo.com wrote:
On Monday, November 11, 2019 at 5:04:08 PM UTC-5, tabby wrote:

Black cloth collectors offer some improvement in efficiency.


NT

I was going to spray paint some aluminum foil black, IIRC. Solar
geeks have found the best-absorbing flat black paints. Aluminum
foil, appropriately supported, is simple to build, and cheap, too.

I was going to flow air on the non-painted side, to eliminate the
any possibility of vapors or smell.

I don't understand the window-screen absorbers -- ISTM they'd let
too much light pass through, wasted. Poor cross-sectional area.

Cheers,
James Arthur

the fact that the air travels thru the cloth means the hot air is kept away from the front glass side, reducing heat loss. 3+ layers of cloth are used to get a dense black overall. This also reduces heat radiation outward as a lot of heat from the cloth layers just hits a neighbouring layer. Plenty of other designs work too.


NT

Got it, thanks.

My notion was to wash the back side of the front glazing with cool
air, minimizing heat loss.

Roughly like this, but IIRC I had a better configuration than this
one...
warm air
^
/|\
..-------. | .-.
: | | |*|
: : | |*|
: : | |*|
: :<~~~~~~~~ glazing
: : | |*|
: : | |*|
: : | |*|<~~ enclosure
: : | |*|
: : |<~~~ absorber plate
: ^ : | |*|
| | |*|
| +-------'*|
| |*********| '*' = insulation
| '---------'
inlet

That approach may have lower flow resistance than window screen.


Cheers,
James Arthur