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gbwillson

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Reply with quote  #51 
Quote:
Originally Posted by Garage_Hermit
Good point:

Quote:
The outside air may hold more moisture in terms of Relative Humidity but less in terms of actual moisture when compared to the warmer inside air.

=========

Dumping warm house air into a "plastic tent" around the collector
like I said above, MIGHT work, providing the house air is DRY enough:

Normally in winter, for health, the house air ought to have a RH of around 50 percent (I believe) (most human lungs not bean built to breathe pure dry air...).

Therefore said house air ought to go through a DRYER first.
(Except Greg's installation just got more expensive, and more complicated...).

Dumping humid house air into a cold collector might make the problem worse, because the house air would COOL and shed its humidity (water), in the form of precipitation, which would then FREEZE.

Therefore, to WHEN and HOW MUCH house air to dump, you would need realtime monitoring of the DEW POINT... or rather BOTH dew points (inside and outside...)

or rather still - three dew points (Inside, Outside and INSIDE COLLECTOR...)

You would need a PLC to do all of this...

Greg's installation just got even more expensive and complicated...

(still, the PLC would also provide temperature readings, and U could slave it to a servo-motor controlled bag deployer...).

==========
OBJECTIVELY [rolleyes], we need to be looking at CONDITIONING systems for collectors forced to operate in extreme cold...

If this was a car, one would say, "keep it in a garage"

If one has no choice but to leave one's car out in the snow, then one gets up a quarter-hour earlier, and turns the car on, to heat up, then goes back in to finish breakfast etc.

(I assume...)

(statement of interest: my car lives outside, and I have to scrape the windows and preheat mainly in in January and February, perhaps 10 times a month, therefore, say, roughly, 20 cold nights...)

Perhaps the solution for a collector would be a NIGHT-BLANKET or cover, PLUS a spirit-heater (fire danger ?) or optimally, an electric infrared heater on a timer that comes on, say, for 30 minutes as soon as the BRIGHTNESS SENSOR says that the sun is coming online...

Or Something Like That...

G_H




What's a PLC?


gbwillson

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Reply with quote  #52 
Funny you should mention covering the collector. I might have considered it, but with the top of the unit over 10 feet off the ground, I thought not. I kinda like the idea, but I doubt my neighbors would. I do like the idea of using a piece of screen over the top. You wouldn't be able to see it and it could be re-tasked in the spring. But covers, heaters and other measures don't fix the root problem. I MAY have identified the problem as air leaks between the manifolds and the collector body. I've corrected most of the air leaks. I should be able to find and seal off the rest over the next day or so.

Greg in MN[wave]
Ky-Jeeper

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Reply with quote  #53 
Sort of like the computer in vechicles. Controls motors switchs,checks temps. Does about anything you need it to do, via a laptop for programing.
Quote:
Originally Posted by gbwillson
Quote:
Originally Posted by Garage_Hermit
Good point:

Quote:
The outside air may hold more moisture in terms of Relative Humidity but less in terms of actual moisture when compared to the warmer inside air.

=========

Dumping warm house air into a "plastic tent" around the collector
like I said above, MIGHT work, providing the house air is DRY enough:

Normally in winter, for health, the house air ought to have a RH of around 50 percent (I believe) (most human lungs not bean built to breathe pure dry air...).

Therefore said house air ought to go through a DRYER first.
(Except Greg's installation just got more expensive, and more complicated...).

Dumping humid house air into a cold collector might make the problem worse, because the house air would COOL and shed its humidity (water), in the form of precipitation, which would then FREEZE.

Therefore, to WHEN and HOW MUCH house air to dump, you would need realtime monitoring of the DEW POINT... or rather BOTH dew points (inside and outside...)

or rather still - three dew points (Inside, Outside and INSIDE COLLECTOR...)

You would need a PLC to do all of this...

Greg's installation just got even more expensive and complicated...

(still, the PLC would also provide temperature readings, and U could slave it to a servo-motor controlled bag deployer...).

==========
OBJECTIVELY [rolleyes], we need to be looking at CONDITIONING systems for collectors forced to operate in extreme cold...

If this was a car, one would say, "keep it in a garage"

If one has no choice but to leave one's car out in the snow, then one gets up a quarter-hour earlier, and turns the car on, to heat up, then goes back in to finish breakfast etc.

(I assume...)

(statement of interest: my car lives outside, and I have to scrape the windows and preheat mainly in in January and February, perhaps 10 times a month, therefore, say, roughly, 20 cold nights...)

Perhaps the solution for a collector would be a NIGHT-BLANKET or cover, PLUS a spirit-heater (fire danger ?) or optimally, an electric infrared heater on a timer that comes on, say, for 30 minutes as soon as the BRIGHTNESS SENSOR says that the sun is coming online...

Or Something Like That...

G_H




What's a PLC?


cutnchop

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Posts: 30
Reply with quote  #54 
PLC, Programmable Logic Controller - Here's the Wiki on it - http://en.wikipedia.org/wiki/Programmable_logic_controller

On some other thread I think I came up with Pullet Launch Controller but this wasn't right [biggrin]



Sounds like you may have found the problem.  I wondered whether flooding the heater with cold air at the end of the day would prevent the condensation as well.  In some (all?) cars when you hit the defog it turns the air conditioning on because this is more effective at removing the moisture.
Garage_Hermit

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Reply with quote  #55 
In some (all?) cars when you hit the defog it turns the air conditioning on because this is more effective at removing the moisture.


Precisely !

It is called "climate control" - see a bit more about it here...

http://www.ask.com/question/what-is-climate-control-in-a-car

No reason why tomorrow's collectors should not use similar technology...

G_H

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(2) It's wrote, "voilĂ " unless talking musical instruments...
gbwillson

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Reply with quote  #56 
Hi All-

I've been enjoying a lot of sunny days for testing the last month on my ZeroPass collector. This is quite the opposite of November and December where a sunny day was a rare commodity. I've overcome the fogging/condensation issues between the layers of the twin-walled glazing. 

With that said I expect to have some solid numbers soon. I still have to test different screen spacing at various fan speeds. I'm testing fans speed as high as 173 CFM or roughly 10 MPH. Results so far have been exciting, with few exceptions. So if you can think of any tests you would like me to explore, let me know now, before I write up my final conclusions.


Greg in MN[wave]
joebehr

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Reply with quote  #57 
Greg
How's that zero-pass screen machine working out for you?
gbwillson

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Reply with quote  #58 
Hi Joe-

The ZP collector is working really well. At times it outperforms the 2-screen and other times it doesn't. It's a really poor passive performer, but due to the design, I would have expected that. What I want to do now is find the optimal settings as far as screen gap AND fan speed. While I have adjusted the screen gap, I haven't yet incorporated any changes in fan speed at the same time. Two days ago I was playing around with max air speeds and noted that at higher speeds(over 150CFM), I had some excellent numbers. But then the clouds rolled in and I haven't been able to get back to testing. The next two days are forecast to be clear. I will say that there looks to be a sweet spot as far as max performance as far as max temperature differential. I just need to find out what that is. So I'll be testing different screen gaps at different fan speed over the next few days and see what happens. If all goes well, I'll have final performance numbers for both collectors very soon. I figure I need 2-3 days as my optima test window is only about 2 hours long due to some trees. Fortunately, the peak hours are from 11am-1pm.

Greg in MN[wave]
joebehr

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Reply with quote  #59 
From all the back & forth info flying around it does seem like one screen being positioned real close to the glazing and one or two layers 3/4" apart for great heat scrubbing you could figure out the best fan speed and cfm for the best performance. If I ever get caught up at work I'm going to build some test panels for zero-pass and also for some of the back pass design with baffles much like Pat B.
solardan1959

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Reply with quote  #60 
I don't think Pat did any backpasses, his was just a flat metal plate with baffles that the air flowed in front of.  Same class as an empty box but with baffles.  But with his claims it seems worth a shot.

Dan
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