Solar Water Heating by Solar Texas

Two Basic Types Open Loop – Household water is circulated through the collectors and gains heat directly from the sun. Subject to damage from freezing Closed Loop – Heat transfer fluid/heat exchanger More complex Good freeze protection

Solar Water Heating in Texas Solar Texas recommends Closed Loop systems almost throughout Texas. Closed Loop systems use a heat exchange fluid to transfer heat from the sun to a separate water storage system. Main benefit: Freeze protection. Solar Loop Heat Exchanger Household Water Storage

System Types For Diehard Enthusiasts Recommended 1. Batch Water Heating For Diehard Enthusiasts 2. Integrated Collector and Storage (ICS) 3. Passive or Thermosiphon (no pumps) Recommended 4. Active (pumps)

Closed Loop Passive Good performance and storage. No pumps, controllers or electronics. Standalone system (has integrated backup).

Closed Loop Passive Can cope with light to short moderate freezes. Storage tank must be positioned above collectors.

How Does it Work? Sun shines on fluid in collectors Warmer fluid in collectors rises and proceeds to a jacket around the household water, and Transfers heat to the household water Cooler fluid descends to bottom of collectors

If the Storage Tank is Moved from Position Above Collectors… Thermosiphon process won’t work Pump/s must be incorporated to move the heat transfer fluid Temperature sensors and a controller must be included to activate the pump/s when heat is available This is an ACTIVE system

Active Drainback Excellent long term operation Excellent freeze protection Failsafe with power loss High temp limited Double pump system – mainly retrofits

Active Drainback Collector on roof. Flow

Active Drainback Storage tank, drainback reservoir with internal heat exchanger. Retrofit to a 50 Gallon electric water heater.

Active Drainback Requires care in installation Takes up a little more space than most SHW’s Owner can provide basic maintenance Single pump system

Active Pressurized Excellent freeze protection Flexible in site requirements Specialized installation equipment Can be problem with power blackouts

Solar Texas P.O. Box 840 Helotes, TX 78023 Ph. (210) 669-2504 Web: www.soltx.com Email: info@soltx.com