Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

Swh 0209


Published on

Published in: Business, Technology
  • Be the first to comment

Swh 0209

  1. 1. Solar Water Heating by Solar Texas
  2. 2. Two Basic Types <ul><li>Open Loop – Household water is circulated through the collectors and gains heat directly from the sun. </li></ul><ul><ul><li>Subject to damage from freezing </li></ul></ul><ul><li>Closed Loop – Heat transfer fluid/heat exchanger </li></ul><ul><ul><li>More complex </li></ul></ul><ul><ul><li>Good freeze protection </li></ul></ul>
  3. 3. Solar Water Heating in Texas <ul><li>Solar Texas recommends Closed Loop systems almost throughout Texas. </li></ul><ul><li>Closed Loop systems use a heat exchange fluid to transfer heat from the sun to a separate water storage system. </li></ul><ul><li>Main benefit: Freeze protection. </li></ul>Solar Loop Household Water Heat Exchanger
  4. 4. System Types 1. Batch Water Heating 2. Integrated Collector and Storage (ICS) 3. Passive or Thermosiphon (no pumps) 4. Active (pumps) Recommended For Diehard Enthusiasts
  5. 5. Batch Heaters <ul><li>Simple and very cheap. </li></ul><ul><li>No backup. Need traditional water heater. </li></ul><ul><li>Will cool water on cold nights. </li></ul><ul><li>Use hot water when it’s available. </li></ul>
  6. 6. Integrated Collector and Storage (ICS) <ul><li>Simple and relatively inexpensive. </li></ul><ul><li>No backup. Need traditional water heater. </li></ul><ul><li>Will cool water on cold nights. </li></ul><ul><li>Use hot water when it’s available. </li></ul>
  7. 7. Integrated Collector and Storage (ICS) <ul><li>Capacity needs to be at least 40 Gallons </li></ul><ul><li>Low iron tempered glass glazing ONLY. </li></ul><ul><li>Lower 2/3rds of tubing should be buried in closed cell insulation. </li></ul>
  8. 8. Closed Loop Passive <ul><li>Good performance and storage. </li></ul><ul><li>No pumps, controllers or electronics. </li></ul><ul><li>Standalone system (has integrated backup). </li></ul>
  9. 9. Closed Loop Passive <ul><li>Can cope with light to short moderate freezes. </li></ul><ul><li>Storage tank must be positioned above collectors. </li></ul>
  10. 10. How Does it Work? <ul><li>Sun shines on fluid in collectors </li></ul><ul><li>Cooler fluid descends to bottom of collectors </li></ul><ul><li>Transfers heat to the household water </li></ul><ul><li>Warmer fluid in collectors rises and proceeds to a jacket around the household water, and </li></ul>
  11. 11. If the Storage Tank is Moved Elsewhere <ul><li>Thermosiphon process won’t work </li></ul><ul><li>Pump/s must be incorporated to move the heat transfer fluid </li></ul><ul><li>Temperature sensors and a controller must be included to activate the pump/s when heat is available </li></ul><ul><li>This is an ACTIVE system </li></ul>
  12. 12. Active Drainback <ul><li>Excellent long term operation </li></ul><ul><li>Excellent freeze protection </li></ul><ul><li>Failsafe with power loss </li></ul><ul><li>High temp limited </li></ul><ul><li>Double pump system – mainly retrofits </li></ul>
  13. 13. Active Drainback <ul><li>Collector on roof. </li></ul>Flow
  14. 14. Active Drainback <ul><li>Storage tank, drainback reservoir with internal heat exchanger. </li></ul>Retrofit to a 50 Gallon electric water heater.
  15. 15. Active Drainback <ul><li>Requires care in installation </li></ul><ul><li>Takes up a little more space than most SHW’s </li></ul><ul><li>Owner can provide basic maintenance </li></ul><ul><li>Single pump system </li></ul>
  16. 16. Active Pressurized <ul><li>Excellent freeze protection </li></ul><ul><li>Flexible in site requirements </li></ul><ul><li>Specialized installation equipment </li></ul><ul><li>Can be problem with power blackouts </li></ul>
  17. 17. Solar Texas P.O. Box 840 Helotes, TX 78023 Ph. (210) 669-2504 Web: Email: