Go Back   EcoRenovator > Improvements > Solar Heating
Advanced Search

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

Thread Tools Display Modes
Prev Previous Post   Next Post Next
Old 11-24-18, 02:35 PM   #1
Geo NR Gee
Journeyman EcoRenovator
Join Date: Jan 2011
Location: Seattle
Posts: 326
Thanks: 109
Thanked 23 Times in 18 Posts
Default Prompt guidance requested in a new Drainback system

Thank you for opening this post. Short version is I have a lot of evacuated tubes sitting on the side of my house collecting dust. I am getting help today to install the racking for the tubes and maybe the tubes.

For the last few weeks, I have been looking for the proper way to use them in a drainback system with water (no antifreeze). These are the Thermomax HP200 tubes and are about 7' per section. They have snapdiscs in them to prevent overheating. Mine are the 195* cut off ones I believe.

Experimenting with the different drain slopes yesterday was to fill the manifold on one end with water and measure how much came out at a specific angle.

It seems like the acceptable result was 1 tablespoon of water left over in a 7' section at 9:12 pitch or 4.4* angle, slope is 7.7% according to the slope calculator. With 3-7' sections, is that a problem for freezing?

I have done weeks of research and frankly it's just going to sit another year unless I just get it done. Hoping someone can save the day before we make a big mistake.

I watched videos by Dr. Ben and he shows many viable ways, but I only see he recommends 1" in 20' or 1/4* slope, however I think that is for a unobstructed manifold. The Thermomax manifolds and other evacuated tube collectors have the heat riser pipe going directly into the liquid stream of the manifold. I tried that with the Thermomax manifold and it is way to much water left inside of the manifold. The 4.4* angle slope is much better if a tablespoon of water over the entire 7' length is acceptable.


Geo NR Gee is offline   Reply With Quote

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 09:56 PM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, vBulletin Solutions Inc.
Ad Management by RedTyger
Inactive Reminders By Icora Web Design