EcoRenovator  

Go Back   EcoRenovator > Improvements > Renovations & New Construction
Advanced Search
 


Blog 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 11-05-09, 12:41 PM   #6
AC_Hacker
Supreme EcoRenovator
 
AC_Hacker's Avatar
 
Join Date: Mar 2009
Location: Portland, OR
Posts: 4,004
Thanks: 303
Thanked 723 Times in 534 Posts
Default Various Methods of Hydronic Floor Installs...

Quote:
Originally Posted by Daox View Post
Wow, that would indicate that in slab would be MUCH more efficient. Especially in a heat pump situation I'd imagine.
As I mentioned, the hydronics guy is referring to conditions around here, and the weather is much milder here than in many parts of the country and world (must remember we have an international audience here!). The feed temps would be higher in areas where the heating demands are greater, but the ratios would stay pretty close.


Nicolas Léonard Sadi Carnot

Heat pumps, in their present state of development, have difficulty making feed water temperatures much over 120. And the Carnot theorem indicates that efficiency is increased as Delta T is decreased. So heat pump + staple up hydronic heating is not a good match.

Here's a table of Thermal Conductivity of common materials...

The reason a slab is more efficient is that concrete is a pretty good conductor (k=0.42 to 1.7), at least compared to wood or MDF (k=0.12 to 0.17), etc. Another reason favoring concrete and gypcrete (AKA: 'the wet system') is that the slab is poured over and around the PEX, so conduction from the PEX to the concrete is assured. The aluminum (k=250) plate idea , even with a U-bend in them are not in 100% contact with the PEX... conduction needs contact.

But weight is a big factor with the slab on a suspended floor, and I have been working and testing and researching this problem for nearly a year. I think I may have come up with a way to keep cost and weight down and performance at an acceptable level.

Stay tuned...

-AC_Hacker

%%%%%%%%%%%
Attached Thumbnails
Click image for larger version

Name:	300px-Sadi_Carnot.jpeg
Views:	3621
Size:	29.2 KB
ID:	450  
AC_Hacker is offline   Reply With Quote
 


Tags
diy, heat pump, hydronic, pex, radiant

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 05:32 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Ad Management by RedTyger
Inactive Reminders By Icora Web Design