EcoRenovator  

Go Back   EcoRenovator > Improvements > Solar Heating
Advanced Search
 


Blog Register 60+ Home Energy Saving Tips Recent Posts Search Today's Posts Mark Forums Read


Reply
 
Thread Tools Display Modes
Old 09-18-11, 06:28 PM   #21
DoctorDoctor
Lurking Renovator
 
Join Date: Sep 2011
Location: Colorado
Posts: 11
Thanks: 0
Thanked 0 Times in 0 Posts
Default

I can't believe that one can do better than this heat exchanger here:

$1000 solar water heating system -- storage tank

Like others, I would be concerned about cross contamination of anti-freeze with the drinking water at the solder points whereas, if one uses intact coil of pex tubing, it has plenty(!) of surface area for heat transfer, it holds a good bit of water in the tubing as a reserve, and I wouldn't have reservations about its integrity of the tubing and cross contamination (although they don't use anti-freeze, the water in the storage tank is not exactly potable having sat in the tank for a year or more).

DoctorDoctor is offline   Reply With Quote
Old 02-17-16, 05:13 PM   #22
triumphman
Lurking Renovator
 
Join Date: Feb 2016
Location: Northeastern,USA
Posts: 2
Thanks: 0
Thanked 0 Times in 0 Posts
Default

I would have put a section of finned baseboard on it, thereby getting some free radiant heat on the vertical run. ( I have some lengths that I scrounged somewhere) FYI
triumphman is offline   Reply With Quote
Old 02-19-16, 12:01 PM   #23
jeff5may
Supreme EcoRenovator
 
Join Date: Jan 2010
Location: elizabethtown, ky, USA
Posts: 2,273
Thanks: 338
Thanked 575 Times in 481 Posts
Send a message via Yahoo to jeff5may
Default

I can't believe I missed this thread! Sorry to revive something long dead, but I didn't do it first...

Ben, how did this experiment turn out? Did it work? If so, did it do well? Did you retire the rig? I'm interested if you can't tell.

I know from experience that this type of supplemental heating can work really well. Not just for solar, but for other types of heat sources as well. From a design standpoint, maximum efficiency of the heat exchanger is not paramount. With a low-grade heat source, there are only a certain number of raw btu available to transfer each pass through, so even with a superconducting exchanger, the gains are not enormous like with steam or a flame. As long as the heat doesn't leak out of the loop, it will come back through on the next pass through.

With this "shotgun" heat exchanger, the best way to improve the efficiency is easy. The unit can be built just like Ben made his, then a length of refrigeration-grade tubing (or a quadruple helix or what have you) can be coiled around the straight length of hard pipe, in between the tees. The heat transfer fluid line can be teed off at the supply and return ends, so that the fluid flows both through the center of the water pipe as well as around the outside. This greatly increases the surface area of both loops, and allows for a higher flow rate through the heating loop. Both factors increase hx effectiveness. If you feel the need to maximize contact area on the outside wall, and don't want to solder the tubing to the pipe, toothpaste or zinc oxide ointment are nearly as good at conducting heat.
jeff5may is offline   Reply With Quote
The Following User Says Thank You to jeff5may For This Useful Post:
stevehull (04-29-16)
Old 04-29-16, 05:10 AM   #24
Michael34
Lurking Renovator
 
Join Date: Nov 2015
Location: Orchard Park, NY
Posts: 4
Thanks: 0
Thanked 0 Times in 0 Posts
Default

I also want to do like this something new for solar hot water system. But let me know that how it's working exactly and the materiel what should we collect how to start this? How many problems you face during this period?
Michael34 is offline   Reply With Quote
Old 04-29-16, 08:25 AM   #25
stevehull
Steve Hull
 
Join Date: Dec 2012
Location: hilly, tree covered Arcadia, OK USA
Posts: 829
Thanks: 241
Thanked 164 Times in 122 Posts
Default

"If you feel the need to maximize contact area on the outside wall, and don't want to solder the tubing to the pipe, toothpaste or zinc oxide ointment are nearly as good at conducting heat."

Jeff, with heat do these two materials get runny? I guess I could do the experiment and put some toothpaste in the microwave . . . .

This is a great suggestion as the standard heat conducting gells are expensive.

Thank you for this quick, easy and inexpensive hack.

Steve
__________________
consulting on geothermal heating/cooling & rational energy use since 1990
stevehull is offline   Reply With Quote
Old 04-30-16, 07:56 AM   #26
jeff5may
Supreme EcoRenovator
 
Join Date: Jan 2010
Location: elizabethtown, ky, USA
Posts: 2,273
Thanks: 338
Thanked 575 Times in 481 Posts
Send a message via Yahoo to jeff5may
Default

The zinc oxide stuff is normally oil-based and it depends on what product you use. It is much more like heat sink grease than toothpaste. Once the joints heat up, surface tension sucks the compound into all the nooks and crannies. I usually use the chapstick stuff on close-fitting joints due to its tenacity. The fish oil and diaper rash stuff works well on joints that move against each other due to dissimilar expansion. Neither of these two really harden completely.

OTOH, toothpaste is a hardening product. It doesn't flow out when it heats up. Over time, the water evaporates out, and it ends up like stale polishing compound, cured drywall mud or hazy car wax. Being water-based, it is much easier to rework or clean up later.If the dried assembly is subject to rattling or dissimilar expansion, the toothpaste will eventually lose contact with at least one surface and crumble off where it can.

jeff5may is offline   Reply With Quote
The Following User Says Thank You to jeff5may For This Useful Post:
stevehull (04-30-16)
Reply


Tags
diy, heat exchanger, solar

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 10:04 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2019, vBulletin Solutions Inc.
Ad Management by RedTyger
Inactive Reminders By Icora Web Design