I was wondering if anyone here would be willing to share their knowledge and perhaps some pictures on what they're running for a heat exchanger in an open heat storage tank. The two options I'm looking at are a home-built copper coil system similar to this:
![Heat Exchangers - Built or Bought Heat Exchangers - Built or Bought](https://www.hearth.com/talk/data/attachments/106/106002-e8e0a37716ab36c855329a136bb437cb.jpg)
Source: http://www.builditsolar.com/Projects/SpaceHeating/DHWSpaceBoiler/DHWSpaceBoiler.htm
Or perhaps a manufactured solution like this:
http://www.outdoorfurnacesupply.com...ries-155-000-btu-pool-spa-heat-exchanger.html
Has anyone tried the second method (the heat exchanger style pictured)? If not that type but another, could you provide suggestions?
![Heat Exchangers - Built or Bought Heat Exchangers - Built or Bought](https://www.hearth.com/talk/data/attachments/106/106002-e8e0a37716ab36c855329a136bb437cb.jpg)
Source: http://www.builditsolar.com/Projects/SpaceHeating/DHWSpaceBoiler/DHWSpaceBoiler.htm
Or perhaps a manufactured solution like this:
http://www.outdoorfurnacesupply.com...ries-155-000-btu-pool-spa-heat-exchanger.html
Has anyone tried the second method (the heat exchanger style pictured)? If not that type but another, could you provide suggestions?