Welcome to the Solar Collector
Brainstorming and Development Page!


 

Home

Hot Air Collector

Hot Water Project 1

Hot Water & Space Heating

Solar Electric

Solar Construction 101

FAQs

Best Collectors

Simply Solar
Sign up Calendar Latest Topics
 
 
 


Reply
  Author   Comment   Page 44 of 46     «   Prev   41   42   43   44   45   46   Next
jamieF

Registered:
Posts: 269
Reply with quote  #431 
lots of bubblewrap goes by my desk daily.  I'll snag some and see if it helps

Rick H Parker

Avatar / Picture

Registered:
Posts: 790
Reply with quote  #432 
Anything solid, porous or liquid that comes in contact with a water molecule in vapor-phase, will steal energy from the water molecules causing it to re-enter the liquid phase.
__________________
Rick H Parker
Kansas, USA
Electronics Engineering Technologist
jamieF

Registered:
Posts: 269
Reply with quote  #433 
the saran wrap is working great. I've lost maybe 1/4" since adding it and the tank was over 40C for most of that time.

Today the tank hit 49.13C and the exchanger in hit 51.25C.  

We're entering a heatwave so I'll need to get the differential controller working as I wouldn't be shocked to see the tank hit 55 or even hotter in the next few days if I don't stagnate the collector. 
stmbtwle

Avatar / Picture

Registered:
Posts: 2,860
Reply with quote  #434 
Glad to hear it's working. It made me think a piece of insulation (bubblewrap?) on top of the saran wrap might help reduce heat loss.

Did you ever get/install the twinwall on the collector?

__________________
Solar is like the wind. It may be free, but putting it to work isn't!
Willie, Tampa Bay
jamieF

Registered:
Posts: 269
Reply with quote  #435 
The entire expansion bucket needs thought about.  Heat loss from it right now is pretty bad and it's 30C outside come winter it will only get worse.     bubble wrap won't do much.
stmbtwle

Avatar / Picture

Registered:
Posts: 2,860
Reply with quote  #436 
That's true, I was thinking in the short term. Suppose you got the smallest bucket you could, put it inside a larger bucket, and fill the gap with foam insulation? Then insulate the lid with polyiso.

You could put the whole show (pump and all) inside a plastic storage box and pack with fiberglass, foam peanuts, or whatever you like.

__________________
Solar is like the wind. It may be free, but putting it to work isn't!
Willie, Tampa Bay
SolarInterested

Avatar / Picture

Spam Stomper
Registered:
Posts: 1,055
Reply with quote  #437 
or just use an insulated container like a picnic cooler.
__________________
Both temperature rise and airflow are integral to comparing hot air collectors
jamieF

Registered:
Posts: 269
Reply with quote  #438 
I'm really busy with everything other than this project  but a quick update.  Tank is at 50C and has been for over a week.   No sign of issues with the tank liner and the saran wrap seems to have stopped the vast majority of the water loss.

The heat shrink glazing on the collector let go on one side in some decent winds while being insanely hot outside.  It may be an OK temporary solution if you need only one sheet but the seam is where the wind got in and torn it to pieces.
SolarInterested

Avatar / Picture

Spam Stomper
Registered:
Posts: 1,055
Reply with quote  #439 
Quote:
Originally Posted by jamieF
...   No sign of issues with the tank liner and the saran wrap seems to have stopped the vast majority of the water loss.
That's really interesting that the regular construction poly has worked as long and as well as it has as a tank liner.

Saw the articles below and thought of your saran wrap cover:
Need to Cover Your Sous Vide Container? Try Sous Vide Ping Pong Balls (link)

Why You Should Add Ping-Pong Balls to Your Sous Vide Bath (link)

__________________
Both temperature rise and airflow are integral to comparing hot air collectors
jamieF

Registered:
Posts: 269
Reply with quote  #440 
Updates - no real progress forward but I have changed a lot on the system.

first I decided that rather than use my homebrewed relay system and controller to activate the pump I'd get something off the shelf and UL certified to keep my house insurance valid...  It turns out that smart plugs are about $30 and go on sale regularly.   For Christmas I recieved a TP-link HS-110 which easily handles the pump and gives me energy usage readings which is neat to know even of not overly useful.   The issue with this route is you need something smart to turn it on and off.  So I took a big detour on the solar project and got interested in smart home tech.   

I setup homeassistant https://home-assistant.io/ on my server.  When it was up and running adding the TP-link was trivial.  I then added a MQTT broker to my server.  And then I rewrote the code on my nodeMCU's to send MQTT data to the broker.   After adding the sensors in homeassistant I added a simple automation to turn the tp-link on and off if the collector surface is > 20 C warmer than the tank temperature.    

This means that I threw away weeks of coding my own thing to end up with almost the same but a "standard". That's ok with me though as  I do this for fun and to learn.

While on the smart home kick I've been replacing all of my light switches with smart dimmers and automating my door locks. 

In the end the solar system worked exactly as intended for 3 days until I noticed it wasn't pumping.   It turns out my dirt cheap chinese pump no longer pumps.   I think that is ultra cheap pump #3 that I've gone through in this project.   I decided I've had enough of replacing those things and installed a grundfos 1/25 3 speed circulator pump  https://www.amazon.ca/gp/product/B000JGH2F6/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1
It's quiet, It's 5 times the price of the old one and it used 52 watts at the lowest speed,   86 at the highest.   I really hope it lasts a good long time.   The antifreeze in the system has corrosion inhibitors so that should help protect the cast iron.  

One thing that I did notice is I have far fewer losses in the trench now.    I used to lose 2+ degrees that way.   right now it's sunny for the first time in weeks and the system is working for the first time since early January.   The collector surface is 60C.   The Collector outlet is 22C the heat exchange inlet is 21.5C, the heat exchange outlet is 19.5C and the collector inlet is 19C.   so it's losting 0.5C to and from the collector.   This is likely due to higher flow rates.  The collector is  gaining about 3C in a pass and the exchanger is transferring about 2C per pass.  The tank (~300 gallons) has gained 3C  in the last 2 hours  going from 13.5C to 16.5C.

Since it gets asked every time I update the poly tank liner still looks fine.  It's discolored but that may be from the water. It's not brittle at all.   The poly on the collector is fogged over.  I really need to replace that with something proper this year.   Of course I said that last year as well...
Previous Topic | Next Topic
Print
Reply

Quick Navigation:

Easily create a Forum Website with Website Toolbox.

 

web statistics