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Thanks for the good photo-thermal systems presentation.

Iron

Good overview of the photo-thermal systems.
Thanks Jon, Ann, Design News and Digi-Key!

Iron

Techniques used for safety when focusing solar: regulate pressure with pressure relief valves and monitor temperature.

Iron

Why don't troughs need tracking? Parabolic shape tracks using a fixed orientation.

Iron

What can be used to hold heat without toxicity? Mineral oils or alchohol.

Iron

Hello from Beaverton, Oregon. Getting caught up...

Iron

Thanks Jon! Very informative. The slides are very nicely prepared. Good pictures, graphics are included to give basic ideas.

Iron

System shutdown, Unfocus of rays from mirrow

No tracing system due to parabiloc shape

What is overall maintenance cost for Panel Solar Absorbers?

Thanks Jon for nice presentation.

Iron

Thank you Jon & Ann, great information.

Iron

hello all from Edmonton, Alberta.

Iron

The powerpoint for the talk is available here:

http://www.glyfac.buffalo.edu/mib/course/marcellus/

Please rspect Jon's time as  it really can be a distracting topic with lots of misinformation.

Iron

If people really want more info -- see this lecture on the marcellus shale.

http://www.youtube.com/watch?v=6Jjb5akEsrI

Dr. Langhorne "Taury" Smith, who works as NYS Geologist within the State Museum, which is part of the State Education Department.

This can be awfully distracting -- so please ...

Iron

??How hard a vacuum do you need for an evacuated tube to work?

Iron

OK -- Thanks everyone -- Hope you will be hear tomorrow -- Jon

 

Iron

If there are any questions I did not address, please chime in now. Sorry if I missed them.

 

 

Iron

Interesting and concerning info about fracking moist of us don't realize...

Thank you for the insights Jon!

Iron

I do write some drilling contracts. Don't want to go off topic though.

If you have a study shoing that amount of leaking -- please let me know where to find the study. Till then it's tough to believe.

 

Iron

"?? Jon, Thanks for the good answer. What is the dark absorbing material in the tube? Can a guy build a tube himself?"

 

There are expermental materials and nanotubes used by some companies for the core but black aluminum will work for a home made flavor. It is the highly transparent, tough, evacuated tube that will be hard to do. You are probably better off buying a ready made system.

Iron

Gees, why isn't the media talking about this? (rhetorical question)

Gold

?? Jon, a little off topic but do you have any information about whether fracking or drilling might release uncontrolled amounts of methane into the atmosphere that could threaten us? It's a bit touchy to talk about this as political tempers could rise.

 

This is a real concern. Methane is a MUCH worse greenhouse gas than CO or CO2. We are already seeing some methane blooms in parts of the oceans. If only 6% of the stored subterranean and sub oceanic methane is released, it could be a mass extinction event for most species.

 

If the permafrost thaws, or the ocean temperature rises enough, it will be problems. I hope we are not too late.

 

And fracking could be a contributor, A recent study found that drill holes are leaking up to 16 % which makes fracking and gas worse than coal.

 

 

 

Iron

?? Jon, Thanks for the good answer. What is the dark absorbing material in the tube? Can a guy build a tube himself?

Gold

thanks for the webinar.

Iron

Thanks, another good class.

Iron

"?? Will you explain the physics of vacuum tubes more on slide 8?"

 

Inside the glass is a dark absorbing material. As it absorbs heat, the heat rises to a top solid collector. Being in contact with a tank, the heat from the collector is transferred to the fluid in the tank. The fluid is transported around a loop to deliver its heat where needed...

Iron

?? Jon, a little off topic but do you have any information about whether fracking or drilling might release uncontrolled amounts of methane into the atmosphere that could threaten us? It's a bit touchy to talk about this as political tempers could rise.

Gold

"I think you mean that a vacuum will not _conduct_ heat. Infrared radiation can travel through a vacuum."

 

Yes, thank you for the correction.

 

 

Iron

try www.sunlit-design.com for one of the DLL units. I think there is another though.

Iron

Answer to question 4 -- Glycol is also commonly used in automotove antifreeze.

 

DO NOT INHALE VAPORS or INGEST. It can burn you too if you are not careful so please, be careful...

 

Iron

Question 3 answer -- safety devices like pressure relief valves, thermal cutoffs, higher diameter steam escape paths, and failsafe coding (if watchdog doesn't respond, do shutdown proceedure - for example).

 

 

Iron

Thanks again, DaveWR

Gold

Jon, Your answer to question 2 is amazing. Duh, I thought I knew geometry better than that.

Gold

BTW: Astronomical Algorithms by Jan Meeus is "The Bible" on the Sun angles. It has the algorithms. See: willbell.com

Iron

Answer to question 2 -- Because they are parabolic which will always focus to the center regardless of suns height.

Iron

"It's cold here most of the year -- six months plus.  I have a patio on the south side of the house -- in the winter on sunny days the furnace never turns on till it is below -25C. The heated air flows up into the attic through the venting and slows the heat loss. The windows allow heat gain.

Much cheaper than active solar."

 

A couple of low cost heliostats could direct even more sunlight to your house to provide it with more heat energy.

Iron

My outdoor wood furnace here in Montana uses plain water in its 400 gal. boiler with just KNo2 (Potassium Nitrite)to prevent corrosion. BTW KNo2 is deadly for cattle. I burn dead trees from a forest fire that would have been burned in piles anyway. Your comments about global dimming were interesting.

Gold

There is a DLL for sun angle calculation and astronomy -- I will see If I can find the link.

Iron

Answer to question 1 -- was mineral oils -- vegetable oils can be used. Jut make sure the breakdown temperature isn't reached.

 

Iron

It's cold here most of the year -- six months plus.  I have a patio on the south side of the house -- in the winter on sunny days the furnace never turns on till it is below -25C. The heated air flows up into the attic through the venting and slows the heat loss. The windows allow heat gain.

Much cheaper than active solar.

Iron

"?? Slide 14. Can you recommend a source for C-code to calculate the position of the sun? Is it open source? I think NOAC has something, but not sure. I understand the need for calibration for calculated systems. Empirical sensing systems are simple and require no calibration."

 

Here is one link I found, there are others using search engines.

 

http://www.iwilltry.org/b/projects/build-a-heliostat-for-solar-heating-and-lighting/

 

 

Iron

Very interesting.  Thank you for the presentation and the response. 

Iron

"?? Years ago I saw an online article by a professor at U of Montana for a passive collector that used two separated layers of window screen wire between Masonite and greenhouse panel to gather cold air at the bottom and output hot air at the top -- good for heating a workshop or barn. Any experience with how well this might work?

 

Yes, this works very well. I did a double walled structure house design many years ago where heat collected at the surface would cause upward flow and draw in cold from below automatically without any sensors or controllers.

The direction of the louvers could be reversed to bring cool air up to the higher levels as well, but I found this needed fans.

 

Cool approach.

 

 

Iron

?? Slide 14. Can you recommend a source for C-code to calculate the position of the sun? Is it open source? I think NOAC has something, but not sure. I understand the need for calibration for calculated systems. Empirical sensing systems are simple and require no calibration.

Gold

"?? I have seen Thermal balance tracking system, no electronics, any thoughts?


I like this idea but haven't seen any that work really well. The 'memory metals' would be good for this. If someone has found a way to do this, please share links. A simple solution is often times an elegant solution.

Iron

?? Years ago I saw an online article by a professor at U of Montana for a passive collector that used two separated layers of window screen wire between Masonite and greenhouse panel to gather cold air at the bottom and output hot air at the top -- good for heating a workshop or barn. Any experience with how well this might work?

Gold

"How do troughs, parabolic dish, flat panel and evac tube collectors compare, thermal capacity versus cost? "

The panels and evacuated tubes are more widely used so by economy of scale, they can be more cost effective. There are a few companies that support trough and heliostat systems, but these are mostly comercial and industrial. For homeowners, typically panels and tubes are the best choice. There are menay that are even certified for rebates from fed and state incentives.

 

Iron

?? I have seen Thermal balance tracking system, no electronics, any thoughts?

Iron

The heliostat is raised to keep the intense heat away, but how is it serviced?

Iron

Very informative, thank you

Another disadvantage of tracking is the loss of efficiency of the overall system...

Iron

Hello,  Thank you for all the kind words. Please prefix questions with a question mark so I can pick themout more easily -- Thanks --

 

Iron

Thanks Jon. First time I've heard the term Global Dimming.

Iron

That was a nice, simple presentation

Iron

Thanks Jon I learnt heat tech from you. Thanks a lot.

Iron

Thank you.  Interesting presentation.

Thanks Jon nice lecture

Iron

Thank  you for today's presentation Jon 

Thank you also Ann

Iron

Thanks Jon!  Great info

Iron

Great presentation, thanks alot, see you tommorrow

Iron

Thanks,

A very ilustrative presentation.

 

Iron

Some sort of guard screen, monitor pressure and temperature

Iron

personal safty, temp control, valve relief etc

Iron

With focused solar technology, heat sensors should be used to prevent overheating of element.

Iron

Closed loop temperature regulation.

Safety: There should be guard screens to keep animals, people, and birds out of the concentrated areas.

Gold

Pressure relief or tempature regulation

Iron

Jon's question was: What technique should always be employed for safety with focusing solar technologies?

Blogger

How do troughs, parabolic dish, flat panel and evac tube collectors compare, thermal capacity versus cost? 

Iron

Always tracking, by nature

no needed due to focus

Iron

Need focus at a point or a line for collection heat.

Iron

No tracking for the trough is needed due to its symmetry.

Iron

Follow and catch the sun

 

Iron

The parabolic shape will focus any light to a single point.

Iron

There are some small parabolic dishes used as a hand held solar powered cigarette lighter.

Iron

Parabolic collectors focus on the center no matter what direction of the incident light.

Iron

Focus on a single point along the tubes axis

 

Iron

Jon's question was: Why don't troughs need tracking systems?

Blogger

Hot water heaters today are typically set for 120°F ~= 50°C maximum to avoid scalding, especially for small children

Iron

ethylene glycol and propylene glycol are probably most common here. (Where it is cold)

Iron

I think you mean that a vacuum will not _conduct_ heat. Infrared radiation can travel through a vacuum.

Gold

Q1: Perhaps ammonia or alcohol.

Iron

?? Will you explain the physics of vacuum tubes more on slide 8?

Gold

but wouldn't salt with heat be corrosive ?

 

So many critics. lol

Iron

Vacuums radiate heat.  They do not convect or conduct it.

Iron

Thought I recall there are specialized oils for this

but wouldn't salt with heat be corrosive ?

Iron

Salt causes crosion into pipe

Iron

Alcohool can be used instead of anti-freeze.

Iron

Salt water makes good antifreeze (or sugar).

Iron

Just use ethanol for a non-toxic antifreeze.  Bootleg whiskey works well :-)

Iron

Jon's question was: What can be used instead of antifreeze to hold heat without toxicity?

Blogger

Jon:  Many people miss the "working with nature" idea for "Gree Energy"! Congratulations -- go to the top of the class! ;-)

Iron

What defines "a colder climate" for your recommendations?

Press the play button on the audio player

 

¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤
Hello from sunny Atlanta

¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤

Iron

No sound again and I refreshed

Iron

Hello everyone Bremen, Gr

Iron

Hi all -Audio is live! If you don't see the audio bar at the top of the screen, please refresh your browser. It may take a couple tries. When you see the audio bar, hit the play button. If you experience audio interruptions and are using IE, try using FF or Chrome as your browser. Many people experience issues with IE. Also, make sure your flash player is updated with the current version. Some companies block live audio streams, so if that is the case for your company, the class will be archived on this page immediately following the class and you can listen then. People don't experience any issues with the audio for the archived version.

Hello from Toronto, Ontario!!

Iron

Good morning from Calgary

Hello from Sunny SE Lake Simcoe Ontario CANADA. Hot and muggy

Iron

Good afternoon from West Point, PA.

Iron

Hello from Inglewood, CA

Iron

Hello again from Monrovia

Iron

Be sure to follow @designnews and @DigiKeyCEC on Twitter for the latest class information. We encourage you to tweet about today's class using the hashtag #CEC.

Blogger

Please join our Digi-Key Continuing Education Center LinkedIn Group at http://linkd.in/yoNGeY

Blogger

Good Morning from rainy and cool Valdez

Hello from Henderson Nevada

Iron

Hi morning every from Vancouver.

Iron

Good afternoon, everyone

Iron

The streaming audio player will appear on this web page when the show starts at 2 PM Eastern time today. Note however that some companies block live audio streams. If when the show starts you don't hear any audio, try refreshing your browser. If that doesn't work, try using Firefox or Google Chrome as your browser. Some users experience audio interruptions with IE. If that doesn't work, the class will be archived immediately following our live taping.

Blogger

Be sure to click 'Today's Slide Deck' under Special Educational Materials above right to download the PowerPoint for today's session.

Blogger

Hello from Scottsdale, AZ

Iron

Hello from Summerville, South Carlina. How's everyone? How is your day going?

Iron

Good Morning from Sheboygan Falls, WI

 

Iron

Morning from Panama City, FL.

Iron

Hello from Hot-in-Chicago

Iron

Howdy from Fort Worth, TX

Iron

Good morning from Edmonton,AB

Iron

Good morning from Tennessee

Iron

Good morning from Mobile, AL

Morning from Portland Oregon

Iron

Missed yesterday.... will pick it up from the archive..

A humble suggestion: Let's preface all our questions that require a response from Jon with a question mark (?) or maybe two (??) so that he can separate the "Thanks" messages, etc. from the actual questions that require a response.

Gold


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